Vacuum tubes are a critical element in many high-end audio products. How do we know when to change them? If you have a question for paul go to: www.psaudio.com/ask-paul/
I worked as a calibration technician for years and I also had to repair any test equipment that failed or degraded. A lot of this equipment used tubes, some of it used 50+ tubes. I was always amazed at how long the tubes in this equipment lasted, it was not unusual to open a up a 15 year old scope and find some original Tektronix tubes in it. The key was this equipment was VERY conservative in it's design, the engineers they employed to design this equipment were the top men in their field. The design was such that the tubes were operated very benignly well below their ratings. I worked on a lot of tube equipment in the army and that equipment was also very conservatively designed. As a rule if you can design a circuit that treats the rube benignly it will last a very long time. There are times when you have to run a tube near it's design limits because it just sounds better there, in those cases the tube will not last as long. I tend to retube my Coinrad Johnson PV10a preamp every 2-3 years. The phono preamp section of that preamp does wear out the 12AX7's faster than the other tubes but I've used an outboard La Pacifica phono preamp for a while now so I can ignore that.
That is interesting about your PV 10. One person who had that amp thought the phono stage was the best thing about it. I owned the same amp myself for a while but never really experimented around to see which part sounded better. I liked the PV 9 a lot if you put in the right NOS tubes to mellow it a bit.
In the Netherlands we had a tube powered medium wave transmitter on the air that was changed for a transistorized one in the mid 1980's. It was still using it's original tube from the late 1930's. That thing was even confiscated and used by the Germans during WW2! So yes, they can last a very very long time as long as they're not working at their maximum ratings.
I have a Prima Luna evo 100 integrated amp. We are told by Prima Luna they run their tubes conservatively. I have been trying to find out which tubes I should change first . The power tubes or the ax7's or indeed the au7 rectifier tubes? PS any modern tube rolling advice for a bright sounding power tube?
Change the tubes once a year might apply to Power tubes like KT88 but definitely does not apply to the smaller input tubes. Mine 12AX7 and 12AT7s are 5 years old and still sound amazing. I know that because 6 months ago, I replaced then all with new tubes (same make and model) and after the break-in period I still couldn't tell the difference between them.
I disagree with having to ,,re-tube,, the system once a year. I own many systems of all sorts and never for the past 8 years had to change tubes ,,definitely not yearly'' in them other that Capacitors and Resistors and perhaps clean switches and pots. I do however own a tube tester and yes I have tested them all (summer last year) but they seem to have between 50-70% life left in them after all this years and yes fairly regular and they all still sound (to my ear) as good as day 1. All amps, preamps, radios, testing equipment that I own contain a total of 237 tubes and only ever had to change 2 tubes (once) because of water spillage (accident caused by my younger daughter) And I have numerous friends who own more or less similar equipment and never had to change a tube in them, ever. So....!? Of course for people who have a lot of money @ their disposal (to waste), well.... by all means go ahead and change it every year. ;)
there is a good reason for changing them every year or two ..it keeps the factories working! and even improving. If they don' make enough ..they SHUT DOWN
My understanding has always been that the equipment will determine the life of the tube. The harder you run the tubes, the less life you get out of them - especially regarding the cathode plating. But, running them harder may yield improved characteristics during that shortened lifespan. Because there are so many different tube components and tube manufacturing variables, you just have to be prepared to get wildly varying anecdotal evidence as to how long they last.
Tubes are great for the output stage of a guitar amp.We like that touch sensitive response.Pick lite and it's clean.Pick hard and it gets dirty.Yea.I worked at H.H. Scott in the 80's.Two of the old engineers were still there,Don Merriman and Peter Globba.I told them about my tube guitar amps.They told me that tubes went out with the Model T.Then I got out my pile of tube amp schematics and the tutorial really started.
I have a tube radio that I use at work, it is on 8 hours a day, 5 days a week. The eye tube is very dim (it was that way when I bought the radio - it is still visible, so I keep the tube), but the radio works fine. I have been using it like this for 2 years now, so there's probably 4000 hours on the tubes (and I do not think that the tubes were new when I bought the radio) and they still work. I had to replace a socket of the output tube (EL84), some capacitors, resistors and the dial lamp, but not any of the tubes.
12ax7 pre amp drivers tubes from sovtek. several different varieties and each with reasonably consistent characteristics. been hooked on them since the early new sensor corp days.
Installed soviet voshkod rockets into my little dot and stored away the stock Chinese made supplied tubes and it was a revelation the sound was astounding thru the cans. 2 yrs on and with occasional use they prob sound better now than from new. I was new to tubes (valves as we call them in uk) and only learned about burning in weeks later but the first few weeks of listening I found the treble a tad too much (the voshkod are renowned for crystal treble reproduction ) but now they have a few miles on the clock the overall sonics are well balanced and defy any reasoning that a cheap amp like the little dot can hold its own against amps costing hundreds more.
Same with me. I have my dad's Pilot 216a preamp and it sounds wonderful. I did however change all the capacitors and many of the out of spec resistors. But the tubes still sound good.
Hey Paul, Bob Carver uses a DC restorer circuit is what he calls it in his tube amps he said he didn't develop it but he got it from the idea from television sets when he was fixing them has something to do with picture tube. He said that that the circuit Idles the tubes when not in use very low current. He said the tubes last about 50 years because of the tidal current is solo they don't waste energy in a lot of heat you know anything about this?
Primaluna amplifier have intelligent system to indicate poor tubes, I wish more companies have to adopt that method for consumer life make easier. New Bob Carver amplifier tubes keep cool running, it will not burn your hand that is also cool feature for other HiFi manufacturers need to must adopt.
My father and his brother bought Yaesu FT 200 HF transceivers at about the same time. His brother left his one turned on 24/7 365. Both radios were still working and had not had a single tube replaced after at least 15 years when both men went to their first transistorized radios. Output power was probably down, but fully operational. I gave my dad my Kenwood TS 430S with the 250 antenna tuner and he used that for another 15 years before he sold everything off and moved to New Zealand.... Nowadays we talk using skype, whatsapp or messenger.....
Between my tube preamp and tube power amp I was changing 24 tubes about once a year. I think the hybrid approach is much better. Put tubes in the voltage amplifying circuits and solid state in the current amplifying circuits. Buying twelve good and matched EL34’s is not easy (but they do sound like heaven).
It's a compromise, but a good one. Allowing the tube to only amplify the voltage does not result in the same level of 'smoothing' that tubes controlling voltage and current do, but due to the lower operating voltages of this, the tubes last longer and suffer less degradation over time.
@Teknogod17 They weren't fine, that is why I was changing them. BTW, I now use a PrimaLuna, much easier on the tubes and they last a lot longer. I now mainly change tubes just because I like to play with the sound.
@Teknogod17 I agree, my current amp is known to be very easy on tubes and over several years I have never had a tube go bad or need replacement unlike other amps I have had which eat tubes for breakfast. I have learned over the years that reliability needs to be near the top of the list when buying audio or anything else. BTW, I love tube rolling just to play around, but I seem to always go back to EL34.
You are right on Dennis, evan my DAC is all tube. I change my pre-amp tubes around every 4-5 years(ECC 83). Power amp has 3 ECC 83s And 4 EL 84s. The EL 84s go down in about 2 years(may be they run so hot and loose efficiancy soon, I do not know).Tubes Are The Way To Go.
From what I know tubes are burned in and tested at the factory, at least they were 60 years ago. Also I have a tube radio with just about all original tubes, they might not sound like new but they still sound great after 64 years and I'm pretty sure most of them will last another 64 years. I sure would like to know how it sounds like with all new tubes though, Sadly most of em aren't made anymore.
I have an old radio, built in 1958. Has the original tubes, not played hard. When the tubes reached 63 years old I noticed the sound was a little off, about 2 years later it got bad sounding, time for new tubes. Another radio I had, gotten rid of, that used tubes required new tubes every couple years, after 6 months they started sounding weak, could get maybe a year or 2 if used sparingly.
I bought a second hand Quicksilver amp with 8417 output tubes back in 1997 for 200 USD as the original owner had concerns that the output tubes had been very hard to find since 1988. The amp still works to this day with the original tubes but I no longer listen to it for long periods because there are EL34 based amps that sound similar (though will less muscular bass cimpared with the 8417 equipped Quicksilver) with more widely available tubes.
the pre amp valves ( mullard) in my 72 marshall superbass are still sounding great. that is now 48 years. not the same as hi fi i know , but still.....
The amount of time that a tube can last depends both on its original quality and how hard it is used. My pre-amp tubes seem to go on for ever, so I presume that they are not pushed too hard in my Conrad Johnson 9a. The ones that I seem to keep replacing are the driver tubes, so I presume that they must have a harder life. I do get the point that they are great for inputs (is this because they present a very high input impedance?), but I also like tube power amps. One thing. I do tend to change to my solid state power in the summer!
If the tubes are driven all the way to their design limits, they won't last long. Some equipment is designed to not push the tubes hard, and then tubes may last decades.
I think it depends on the volume that you are pushing, like tube preamps lasts much longer when compared to guitar power amps that play loud most of time
Paul, Can you extend tube life by not turning of the equipment every night? I am somewhat of the opinion that it is the cold start up that wears out vacuum tubes in tube amplifiers and even in tube preamplifiers. My gear is not high end just for a reference. I always let my tubes warm up before using the amplifier for a few minutes. I wait at least 20 minutes before I push the volume. I have noticed that my tube preamps and even tube amplifiers sound better after being on all day long. Peter
I have very little experience with tubes. I just have two in the preamp of my Rogue Sphinx V3. I have found that replacing them every one to two years is about right. I notice that the midradge starts to disipate after a year or so of steady listening.
The tube warm up is all about the heaters, you want a slow warm up so there is no cathode striping......the metal work inside the glass is coated with various compounds. Also critical is the plate voltages and specially on power tubes. Tube have a curve in response, so they generally get designed into a circuit to run in the linear portion of the curve which can be influenced by the plate voltage and the current. The tube manuals give the curves and the specs and the graphs per the manufacturer and tube type......its not always generic. With tubes....you don't want to red plate them. You have to know the class of operation that the piece is designed for. AND if its push-pull class AB, there can be a crossover notch distortion point in the sine wave that you want to minimize. The whole balance of factors can be tricky. But if the tubes are not being run hard, and they have a good vacuum......you can go a few thousand hours. BUT when domestic tubes are not being manufactured anymore, the existing supplies are being depleted and what might be in circulation today might not be 100% performance tubes...the could be yesterdays era rejects of defectives put back in circulation. Beware of non domestic tubes, some European tubes are actual correct tubes as with JJ/tesla which if I'm not mistaken was set up on telefunken machinery and recipies/designs. The Russian tubes are usually not authentic and can be relabeled tubes domestic to Russia and technically just equivalent tubes rather than the real design. I'm not sure as to if this is getting corrected as there has been a resurrection of some domestic brand names put on to Russian produced tubes. NOS domestic or NOS European tubes will be extremely pricey as compared to the Russian tubes....though the Russian tubes are current manufacture. There is a lot of attention in the Russian market and manufacturing, so quality can be really good....as far as I know. Best bet is to have a full spare set of tubes on hand. The power tubes are the real wear and tear tubes in a system. Vibration is the enemy as well as heat.....so anything tube should be as isolated as possible from vibration and its a good idea to use a fan as long as there is not electrical interference with the audio.....you don't want a tube set enclosed in a closet or cabinet.....air circulation is the key. Solid state uses a heat sink, and as long as the heat sink is big enough to be properly adequate …...heat isn't as big an issue with solid state. In the days of carbon resistors, the heat can cause drift in the components of the circuitry, and specially the power rail electrolytic capacitors & the signal bypass's. I deal with audio as in the direction of guitar amplification which is not to far from audio playback, but in the aspect of guitar....its not about being clean.....its all about distortion and overdrive. One of the secrets in guitar amps is due to design and layout, but its a happy accidental situation. The old carbon type resistors tend to drift up in value as they heat up, heat rises.....tube make heat so it gets absorbed into the chassis.....thus the plate resistors drift up.....which means the gain drifts up along with the distortion & overdrive...and particularly when the plate resistor is not of the right size for the plate voltage (1/2 watt vs a 1 or 2 watt)…...so it becomes a cascading event & phenomenon . Plates drift up for gain, power rail voltage supply begins to dip as the respective resistors heat up...which shifts the tube curve due to plate voltage in conjunction with the gain factor of the plate resistors...…..there isn't a locked in stability but its not a really bad situation with stability in the case of a guitar amplifier. SO an audio play back set has to have a good design layout which suggest being huge as opposed to the compactness of electronics as we have come to know them in this day and age......not that the compact factor wasn't present in the era. High end tube audio pieces tend to have an appearance of a piece of modern artwork.....for a reason as opposed to just being a box with electronic guts inside. 6550 power tubes and KT88/KT90 power tubes are the most linear of the current production power tubes, and I believe there is now a KT120 power tubes which packs a lot of power in it......clean linear tubes (not that they can't be made to distort but its way at the end of their limits when it occurs). Tubes are interesting......as with the one Edison light bulb in some firehouse somewhere in California.....100 years old or alittle more and the filament is still burning (due to good vacuum and seal......not designed obsolescence), so that can carry over to audio vacuum tubes in a perfect world......but reality is different when you want to sale tubes & in the era when tubes ruled......but atleast the electronic circuit was unitized and the tube was removeable and easy maintenance......as opposed to solid state & any potential failure. If I remember right, my Macintosh receiver is hybrid and they were smart enough to socket the transistors......which should carry over to IC's...….but I'm particular.....just me
I'd love to hear your thoughts on the retubed system, but try putting the year old preamp tubes back in and see if they don't sound great. I think there's less need to replace those. Compared to the output tubes. Pre tubes should last for a very long time...many years, or a decade or more. Thanks!
Pretty interesting. Tubes for guitar amps can become pretty scarce now. Just a first gen CyberTwin that hasn't gigged for years but still sounds good. Mace and Blues Jr are gone. Miss them but,,,,,
Hello, I own a Mcintosh MA230 integrated tube amp and am having issues with the left speaker. It is very low and the sound that comes out of it is hissy and crackly. the speakers work fine when i run the right channel through them so i know its not the wire, connection or the speaker itself. My question is, can a bad tube effect only one speaker? The other speaker sounds great. Your wisdom would be greatly appreciated. Thanks.
Yes. You have different output tubes for each channel. Swap the tubes for the left channel with the right channel ones and I bet that your right channel will sound bad and the left one good. Your preamp section is solid state so that is most likely not the culprit. Well since I just noticed your post is almost a year old you probably have it figured out already. Great amp!
I love output tubes. Of course if you asked Paul a year ago he might have said tubes do NOT sound better it the input stage. Viva KT88s! If you can use them in triode mode and still power your speakers properly, they give you most of the great tube sound with almost no downfall. Lots of music energy. I have heard some good MOSFET amps. Nagra - if you’ve can afford Swiss. Still, it’s a different kind of sound - very natural.
Not sure what the difference might be between tubes used in ur type of amps vs guitar amps . I bought an amp a few yrs ago made in 1978 . The preamp tubes were original the prw tubes had been replaced once . The 1st owner was the seller . Still sounded good as ud want . Changed the preamp tubes with no change in sound . Friend of mine says tubes aren't made as good as they were . Is that why us want to change them every ur?
They are great for guitar amps, other gear doesn't really benefit from harmonic distortion. Usually they are too big and loud to play at optimal volume. Attenuators affect tone, amp/speaker interactivity and shorten tube life, so a small single ended guitar amp can be the best choice.
Under normal design range and operating loads of the normal condition preamp tubes (12au, 12ax, etc), you may replace them in 3 to 5 years for daily usage of 3 to 6 hrs a day, I anticipated. The "failure stage" could be longer.
As far as the various tubes that I use, they range in lifespan between 2500 and 5000 hours of use, as per the manufacturer's data sheet. Now, as far as when the sound degradation becomes apparent/ noticeable I'd have to say depends on your own ears.
It really depends on how much you use them, what their application is and the quality of them. I can’t talk for hifi amps but I found with guitar amps that the power section ones only last about a year, preamp ones can last several years .
My ex band mate plays regularly with two bands. His Fender DeVille 212 has hadoriginal tubes +20 years and still working just fine. Only maintenance has been replacing one input jack and one fuse.
I had my 7 years old high end tube amp checked last week and they said they are in great condition and there is no point in changing. I'm using this amp everyday for many hours.
Aw man.. I don't know what input stage and output stage means.. would somebody help me out with that? Tried googling it, nothing clear came up. In puts are PC's, turntables, streamers ect. In my mind an output is a TV or a set of speakers but I don't know what input stage or output stage means in this context.
Dang, I've had the same factory tubes in my Mesa Boogie Strategy 500 since 1994 when I bought it new. I'd probably change tubes out more often if it didn't cost $400 a pop.
in the 60's you could go to the corner drug store & put them on a tester....my guitar amp may need some new ones ...I am hearing a sizzle or maybe there is a lose cover or something.
I’m a guitarist so my needs may be different. My amp uses tubes, 12ax7s and EL34s. After replacing Russian and Chinese tubes far too often I took the plunge and bought NOS and as-new used Mullard tubes from England. The NEWEST of these is a mid seventies NOS set of EL34s, the oldest is a 12ax7 date coded August 1960, same as me. They all work and test better than brand new reproductions. Perhaps the need to replace annually reflects the poor quality of modern tubes rather than the longevity of old school quality control. Maybe I’m just hard of hearing. :)
take it from a guitarist. tubes can last 15 years or 15 months, or 15 weeks. really depends on your luck of the draw and how hard and often you use them, and whether you let them warm up or not. how often should you replace them however is a much easier question to answer: once a year is a luxury! once every two and youre doing really well. once every 5, well, youre getting your moneys worth at least.... if you cant do them every year or two, then the answer is simply as often as your budget permits it
Just think of them like incandescent light bulbs, really. They can last a lifetime if they happen to have flaws and never have any stress on them (power cycles) or they could go out in a week or two for no apparent reason.
I get around 5 years on a set of XF1's in my 8B. I get around 2 years using the reissue Mullard EL34's by New Sensor. Not as good as the originals but easily the best non NOS version for my gear - even better than Winged C.
Annual tube changeovers are excessive unless you run them nearly constantly. Not to mention the cost! Of course, your IRS towers are highly resolving and require a lot of power, so maybe it might be worthwhile in that case.
what is not being made clear is....hours of service. Tubes are kind of rated like a light bulb.....how many hours it should be expected to burn....BECAUSE they both use a thoriated tungsten filament...light bulbs and vacuum tubes. SO if his listening room system is constantly ON...it accumulates hours. Tubes generally are good for several thousand hours.....and if they have a good vacuum and seal...they could go longer. Also factored in is the on/off cycle which could eventually cook off the coatings on the metal parts within the vacuum....so there are other factors for wear and tear.....remembering that cycling on/off also imparts heating and cooling thus expansion and contraction.....so there are basic factors hiding in front of your nose in the matter. BUT in a perfect world they theoretically could last indefinitely. The designed obsolescence factor is the actual vacuum in the glass.....as that can be manipulated as with light bulbs...the science was so precise in manufacturing.......profits depend on repeat sales based on a cycle of longevity and controlling the aspects of longevity.
to illustrate....the edison light bulb in some firehouse out in california has been burning for 100 years.........as it was produced prior to the concept of designed obsolescence in business. So basically it came off the assembly line with an extremely good vacuum and has been permitted to burn steady and not been subject to adversity's.....like extreme vibrations and on/off cycles......its been in a steady state. You definitely wouldn't find a modern chinese made light bulb that would ever last that long ......since they are not made in america these days......and they are made post era of designed obsolescence in the business models.......you might be lucky to get a month or 2 out of a chinese light bulb.
You can tell when preamp tubes are going when the sound gets hissy and lacks dynamics. You know it takes alot longer for a transistor amp to warm up and sound good than a tube amp. Some tubes will last a very long time like some Telefunkens while chinese made tubes are good for about 6 months.
I understand why you replaced all of the tubes, kind of a shotgun technique. There's a really good chance that only one tube was failing and quite a bit of detective work would have been required to find out which one.
You’re right in that tube slowly degrading performance and it’s very deceptive and hard to see but tubes have a very definite life expectancy especially power tubes my holy Grail of the RCA tubing guy Manuel it estimates 1000 hours of full power before the amount of electrodes are burned off by the The cathode decreases to an amount that is unsatisfactory to meet the specs power tubes 1000 hours is usually considered to be a year is used for hi-fi same with stylus is on cartridges once a year low level tubes is well they asked seven for example is not wearing out it will lose the seal as you say but otherwise they last a long long time
about a year service life is a common design flaw. I have full scratch builds running over 10 years now, using same tubes.... Too bad no one listens to me........
Paul is like the grandpa' at the Xmas dinner when you ask him a question, then you're half way through the dinner when he finally gets to the answer 😂 in the mean time you already forgot what the question was😂
I disagree with you on 2 things. first, you don't have to replace tubes once a year. That's like changing the oil for your car daily. Second: Pure tube amps sound much better than a hybrid amp. I have tried both.
I'm not an expert on this stuff by no means, but if you have to replace your tubes every year you must have some pretty shitty tubes. Or maybe you just leave the amp burning 24/7 for a year.
It’s way more convoluted than Paul’s answer regarding tubes. It depends on the quality of tubes, listener, system & parameters the tubes are operated at, age & hours on tubes. Also, with tubes there is always an upgrade path.
Just say it tubes are not worth the headache 🤕 for the money,I listen to a lot of music every day and loosing quality of sound slowly over time is not what I want to put my money into,never for me
don't skimp on preamp tubes if you care about your tone ,your money and your sanity. modern preamp tubes(china ussia \slovakia) last up to 2000 hours .nos preamp tubes last 10000 hours or more . the fact that audiophiles put cheap (10- 40$ each)russian or chinese made components in their high end preamp is crazy since: 1. they sound so bad compared to nos. do an a\b comparison trust your ears( not paul in this case he is marketing his gear which uses russian tubes as the heart of the amp ) 2. they don't last as long as nos. you have to worry about it every year and buy tubes again. paul uses 40$ a piece new sensor genalex tubes (all russian tubes are made in the same factory these days sovtek genalex eh mullard ri brimar tung sol groove tubes all sovtek with nicer labels and boxes)which costs 40$ .even though proper nos tubes costs 2 or 3 times that price ,they sound better ,last longer and keep you free from stupid worries you shouldnt have with high end gear. let's say you have only 5 tubes so 200$ a year for every year of uncertainty and harsh sound or about 500$ for 5 years of sweet sound (so say audiophiles in the last 70 years) and peace of mind. you can buy nos from reputable stores and dealers :upscale audio thetubestore tubedepot etc
wah your tubes only last a year is only about 2000 hrs n the sound turn bad n lose it magic this is not good for business maybe your engineer have turn up the bias too much that why the tubes only go for 2000 hrs n they start to turn bad
Change them once a year? No. Absolute nonsense. *test* them once a year and bias them every 3 to 6 months after initial burn in. If you're having to change your tubes out once a year, you need to check your gear. Even cheap tubes last longer than that.
Dude, the question was how long do tubes last? WTF 3:29 I'm bailing out. Still have no idea what the answer is in your opinion but I know about 500 other things I could care less about.
I worked as a calibration technician for years and I also had to repair any test equipment that failed or degraded. A lot of this equipment used tubes, some of it used 50+ tubes. I was always amazed at how long the tubes in this equipment lasted, it was not unusual to open a up a 15 year old scope and find some original Tektronix tubes in it. The key was this equipment was VERY conservative in it's design, the engineers they employed to design this equipment were the top men in their field. The design was such that the tubes were operated very benignly well below their ratings. I worked on a lot of tube equipment in the army and that equipment was also very conservatively designed.
As a rule if you can design a circuit that treats the rube benignly it will last a very long time. There are times when you have to run a tube near it's design limits because it just sounds better there, in those cases the tube will not last as long. I tend to retube my Coinrad Johnson PV10a preamp every 2-3 years. The phono preamp section of that preamp does wear out the 12AX7's faster than the other tubes but I've used an outboard La Pacifica phono preamp for a while now so I can ignore that.
That is interesting about your PV 10. One person who had that amp thought the phono stage was the best thing about it. I owned the same amp myself for a while but never really experimented around to see which part sounded better. I liked the PV 9 a lot if you put in the right NOS tubes to mellow it a bit.
In the Netherlands we had a tube powered medium wave transmitter on the air that was changed for a transistorized one in the mid 1980's. It was still using it's original tube from the late 1930's. That thing was even confiscated and used by the Germans during WW2! So yes, they can last a very very long time as long as they're not working at their maximum ratings.
I have a Prima Luna evo 100 integrated amp. We are told by Prima Luna they run their tubes conservatively. I have been trying to find out which tubes I should change first . The power tubes or the ax7's or indeed the au7 rectifier tubes?
PS any modern tube rolling advice for a bright sounding power tube?
Change the tubes once a year might apply to Power tubes like KT88 but definitely does not apply to the smaller input tubes. Mine 12AX7 and 12AT7s are 5 years old and still sound amazing. I know that because 6 months ago, I replaced then all with new tubes (same make and model) and after the break-in period I still couldn't tell the difference between them.
I disagree with having to ,,re-tube,, the system once a year. I own many systems of all sorts and never for the past 8 years had to change tubes ,,definitely not yearly'' in them other that Capacitors and Resistors and perhaps clean switches and pots. I do however own a tube tester and yes I have tested them all (summer last year) but they seem to have between 50-70% life left in them after all this years and yes fairly regular and they all still sound (to my ear) as good as day 1. All amps, preamps, radios, testing equipment that I own contain a total of 237 tubes and only ever had to change 2 tubes (once) because of water spillage (accident caused by my younger daughter) And I have numerous friends who own more or less similar equipment and never had to change a tube in them, ever. So....!?
Of course for people who have a lot of money @ their disposal (to waste), well.... by all means go ahead and change it every year. ;)
I agree. Why is it that you can still power up a vintage tube Amp after so many decades
there is a good reason for changing them every year or two ..it keeps the factories working! and even improving. If they don' make enough ..they SHUT DOWN
Wow changed my tubes after 5 years what a difference. Was even thinking of buying a new system saved some money. Thanks Paul
My understanding has always been that the equipment will determine the life of the tube. The harder you run the tubes, the less life you get out of them - especially regarding the cathode plating. But, running them harder may yield improved characteristics during that shortened lifespan. Because there are so many different tube components and tube manufacturing variables, you just have to be prepared to get wildly varying anecdotal evidence as to how long they last.
Tubes are great for the output stage of a guitar amp.We like that touch sensitive response.Pick lite and it's clean.Pick hard and it gets dirty.Yea.I worked at H.H. Scott in the 80's.Two of the old engineers were still there,Don Merriman and Peter Globba.I told them about my tube guitar amps.They told me that tubes went out with the Model T.Then I got out my pile of tube amp schematics and the tutorial really started.
My Philips 807 and RCA 1625 tubes work fine for more than 28 years.
Cheers from Indonesia
I have a tube radio that I use at work, it is on 8 hours a day, 5 days a week. The eye tube is very dim (it was that way when I bought the radio - it is still visible, so I keep the tube), but the radio works fine. I have been using it like this for 2 years now, so there's probably 4000 hours on the tubes (and I do not think that the tubes were new when I bought the radio) and they still work. I had to replace a socket of the output tube (EL84), some capacitors, resistors and the dial lamp, but not any of the tubes.
12ax7 pre amp drivers tubes from sovtek. several different varieties and each with reasonably consistent characteristics.
been hooked on them since the early new sensor corp days.
Installed soviet voshkod rockets into my little dot and stored away the stock Chinese made supplied tubes and it was a revelation the sound was astounding thru the cans. 2 yrs on and with occasional use they prob sound better now than from new. I was new to tubes (valves as we call them in uk) and only learned about burning in weeks later but the first few weeks of listening I found the treble a tad too much (the voshkod are renowned for crystal treble reproduction ) but now they have a few miles on the clock the overall sonics are well balanced and defy any reasoning that a cheap amp like the little dot can hold its own against amps costing hundreds more.
I have a preamp with 12ax7 tubes from 1960 and they still sound good.
Same with me. I have my dad's Pilot 216a preamp and it sounds wonderful. I did however change all the capacitors and many of the out of spec resistors. But the tubes still sound good.
Hey Paul, Bob Carver uses a DC restorer circuit is what he calls it in his tube amps he said he didn't develop it but he got it from the idea from television sets when he was fixing them has something to do with picture tube. He said that that the circuit Idles the tubes when not in use very low current. He said the tubes last about 50 years because of the tidal current is solo they don't waste energy in a lot of heat you know anything about this?
Primaluna amplifier have intelligent system to indicate poor tubes, I wish more companies have to adopt that method for consumer life make easier. New Bob Carver amplifier tubes keep cool running, it will not burn your hand that is also cool feature for other HiFi manufacturers need to must adopt.
Great question and great answer
Great explanation ! Done well !
Paul, you still haven’t heard Kondo Japan tubes on the output stage on properly designed conical horns. It will change how think about endgame sound.
My father and his brother bought Yaesu FT 200 HF transceivers at about the same time. His brother left his one turned on 24/7 365. Both radios were still working and had not had a single tube replaced after at least 15 years when both men went to their first transistorized radios. Output power was probably down, but fully operational. I gave my dad my Kenwood TS 430S with the 250 antenna tuner and he used that for another 15 years before he sold everything off and moved to New Zealand.... Nowadays we talk using skype, whatsapp or messenger.....
Between my tube preamp and tube power amp I was changing 24 tubes about once a year. I think the hybrid approach is much better. Put tubes in the voltage amplifying circuits and solid state in the current amplifying circuits. Buying twelve good and matched EL34’s is not easy (but they do sound like heaven).
It's a compromise, but a good one.
Allowing the tube to only amplify the voltage does not result in the same level of 'smoothing' that tubes controlling voltage and current do, but due to the lower operating voltages of this, the tubes last longer and suffer less degradation over time.
I don't agree, I have used both and pure tube amps are far better.
@Teknogod17 They weren't fine, that is why I was changing them. BTW, I now use a PrimaLuna, much easier on the tubes and they last a lot longer. I now mainly change tubes just because I like to play with the sound.
@Teknogod17 I agree, my current amp is known to be very easy on tubes and over several years I have never had a tube go bad or need replacement unlike other amps I have had which eat tubes for breakfast. I have learned over the years that reliability needs to be near the top of the list when buying audio or anything else. BTW, I love tube rolling just to play around, but I seem to always go back to EL34.
You are right on Dennis, evan my DAC is all tube. I change my pre-amp tubes around every 4-5 years(ECC 83). Power amp has
3 ECC 83s And 4 EL 84s. The EL 84s go down in about 2 years(may be they run so hot and loose efficiancy soon, I do not know).Tubes Are The Way To Go.
From what I know tubes are burned in and tested at the factory, at least they were 60 years ago. Also I have a tube radio with just about all original tubes, they might not sound like new but they still sound great after 64 years and I'm pretty sure most of them will last another 64 years. I sure would like to know how it sounds like with all new tubes though, Sadly most of em aren't made anymore.
I have an old radio, built in 1958. Has the original tubes, not played hard. When the tubes reached 63 years old I noticed the sound was a little off, about 2 years later it got bad sounding, time for new tubes. Another radio I had, gotten rid of, that used tubes required new tubes every couple years, after 6 months they started sounding weak, could get maybe a year or 2 if used sparingly.
I'm pretty new to tube amps... My _new_ Randall blew two fuses back to back. Is this likely a bad tube?
thank you.... same ,, situation i am facing now, my pre amp not sound as like earlier and i orderd new tubes
I bought a second hand Quicksilver amp with 8417 output tubes back in 1997 for 200 USD as the original owner had concerns that the output tubes had been very hard to find since 1988. The amp still works to this day with the original tubes but I no longer listen to it for long periods because there are EL34 based amps that sound similar (though will less muscular bass cimpared with the 8417 equipped Quicksilver) with more widely available tubes.
@Laurentz Duba - to my ears, the 8417 tube sounds like a 1990s era solid state amp designed by Tom Evans.
Paul- what is the concept of warm sounding gear like tube amps?
the pre amp valves ( mullard) in my 72 marshall superbass are still sounding great. that is now 48 years. not the same as hi fi i know , but still.....
Great info. Thank you sir.
The amount of time that a tube can last depends both on its original quality and how hard it is used.
My pre-amp tubes seem to go on for ever, so I presume that they are not pushed too hard in my Conrad Johnson 9a.
The ones that I seem to keep replacing are the driver tubes, so I presume that they must have a harder life.
I do get the point that they are great for inputs (is this because they present a very high input impedance?), but I also like tube power amps.
One thing.
I do tend to change to my solid state power in the summer!
If the tubes are driven all the way to their design limits, they won't last long. Some equipment is designed to not push the tubes hard, and then tubes may last decades.
My current radio the tubes lasted 65 years before they got replaced.
I think it depends on the volume that you are pushing, like tube preamps lasts much longer when compared to guitar power amps that play loud most of time
Of course build year and quality also can change life, I have tubes from 1960 and they are still pretty fine, but many from 60's died aswell
Paul, Can you extend tube life by not turning of the equipment every night? I am somewhat of the opinion that it is the cold start up that wears out vacuum tubes in tube amplifiers and even in tube preamplifiers. My gear is not high end just for a reference.
I always let my tubes warm up before using the amplifier for a few minutes. I wait at least 20 minutes before I push the volume.
I have noticed that my tube preamps and even tube amplifiers sound better after being on all day long.
Peter
I have very little experience with tubes. I just have two in the preamp of my Rogue Sphinx V3. I have found that replacing them every one to two years is about right. I notice that the midradge starts to disipate after a year or so of steady listening.
The tube warm up is all about the heaters, you want a slow warm up so there is no cathode striping......the metal work inside the glass is coated with various compounds. Also critical is the plate voltages and specially on power tubes. Tube have a curve in response, so they generally get designed into a circuit to run in the linear portion of the curve which can be influenced by the plate voltage and the current. The tube manuals give the curves and the specs and the graphs per the manufacturer and tube type......its not always generic. With tubes....you don't want to red plate them. You have to know the class of operation that the piece is designed for. AND if its push-pull class AB, there can be a crossover notch distortion point in the sine wave that you want to minimize. The whole balance of factors can be tricky. But if the tubes are not being run hard, and they have a good vacuum......you can go a few thousand hours. BUT when domestic tubes are not being manufactured anymore, the existing supplies are being depleted and what might be in circulation today might not be 100% performance tubes...the could be yesterdays era rejects of defectives put back in circulation. Beware of non domestic tubes, some European tubes are actual correct tubes as with JJ/tesla which if I'm not mistaken was set up on telefunken machinery and recipies/designs. The Russian tubes are usually not authentic and can be relabeled tubes domestic to Russia and technically just equivalent tubes rather than the real design. I'm not sure as to if this is getting corrected as there has been a resurrection of some domestic brand names put on to Russian produced tubes. NOS domestic or NOS European tubes will be extremely pricey as compared to the Russian tubes....though the Russian tubes are current manufacture. There is a lot of attention in the Russian market and manufacturing, so quality can be really good....as far as I know.
Best bet is to have a full spare set of tubes on hand. The power tubes are the real wear and tear tubes in a system. Vibration is the enemy as well as heat.....so anything tube should be as isolated as possible from vibration and its a good idea to use a fan as long as there is not electrical interference with the audio.....you don't want a tube set enclosed in a closet or cabinet.....air circulation is the key. Solid state uses a heat sink, and as long as the heat sink is big enough to be properly adequate …...heat isn't as big an issue with solid state. In the days of carbon resistors, the heat can cause drift in the components of the circuitry, and specially the power rail electrolytic capacitors & the signal bypass's.
I deal with audio as in the direction of guitar amplification which is not to far from audio playback, but in the aspect of guitar....its not about being clean.....its all about distortion and overdrive. One of the secrets in guitar amps is due to design and layout, but its a happy accidental situation. The old carbon type resistors tend to drift up in value as they heat up, heat rises.....tube make heat so it gets absorbed into the chassis.....thus the plate resistors drift up.....which means the gain drifts up along with the distortion & overdrive...and particularly when the plate resistor is not of the right size for the plate voltage (1/2 watt vs a 1 or 2 watt)…...so it becomes a cascading event & phenomenon . Plates drift up for gain, power rail voltage supply begins to dip as the respective resistors heat up...which shifts the tube curve due to plate voltage in conjunction with the gain factor of the plate resistors...…..there isn't a locked in stability but its not a really bad situation with stability in the case of a guitar amplifier. SO an audio play back set has to have a good design layout which suggest being huge as opposed to the compactness of electronics as we have come to know them in this day and age......not that the compact factor wasn't present in the era.
High end tube audio pieces tend to have an appearance of a piece of modern artwork.....for a reason as opposed to just being a box with electronic guts inside. 6550 power tubes and KT88/KT90 power tubes are the most linear of the current production power tubes, and I believe there is now a KT120 power tubes which packs a lot of power in it......clean linear tubes (not that they can't be made to distort but its way at the end of their limits when it occurs).
Tubes are interesting......as with the one Edison light bulb in some firehouse somewhere in California.....100 years old or alittle more and the filament is still burning (due to good vacuum and seal......not designed obsolescence), so that can carry over to audio vacuum tubes in a perfect world......but reality is different when you want to sale tubes & in the era when tubes ruled......but atleast the electronic circuit was unitized and the tube was removeable and easy maintenance......as opposed to solid state & any potential failure. If I remember right, my Macintosh receiver is hybrid and they were smart enough to socket the transistors......which should carry over to IC's...….but I'm particular.....just me
I'd love to hear your thoughts on the retubed system, but try putting the year old preamp tubes back in and see if they don't sound great. I think there's less need to replace those. Compared to the output tubes. Pre tubes should last for a very long time...many years, or a decade or more. Thanks!
Pretty interesting.
Tubes for guitar amps can become pretty scarce now.
Just a first gen CyberTwin that hasn't gigged for years but still sounds good.
Mace and Blues Jr are gone. Miss them but,,,,,
Hello, I own a Mcintosh MA230 integrated tube amp and am having issues with the left speaker. It is very low and the sound that comes out of it is hissy and crackly. the speakers work fine when i run the right channel through them so i know its not the wire, connection or the speaker itself. My question is, can a bad tube effect only one speaker? The other speaker sounds great. Your wisdom would be greatly appreciated. Thanks.
Yes. You have different output tubes for each channel. Swap the tubes for the left channel with the right channel ones and I bet that your right channel will sound bad and the left one good. Your preamp section is solid state so that is most likely not the culprit. Well since I just noticed your post is almost a year old you probably have it figured out already. Great amp!
I love output tubes. Of course if you asked Paul a year ago he might have said tubes do NOT sound better it the input stage. Viva KT88s! If you can use them in triode mode and still power your speakers properly, they give you most of the great tube sound with almost no downfall. Lots of music energy. I have heard some good MOSFET amps. Nagra - if you’ve can afford Swiss. Still, it’s a different kind of sound - very natural.
Can I ask what that machine is that you are sitting in front of? I see it often and have no idea what it is :-)
if the sound degraded during one year it's modern tubes. nos preamp tubes last 10.000 hours. try nos telefunken simens or mullard tubes
Not sure what the difference might be between tubes used in ur type of amps vs guitar amps . I bought an amp a few yrs ago made in 1978 . The preamp tubes were original the prw tubes had been replaced once . The 1st owner was the seller . Still sounded good as ud want . Changed the preamp tubes with no change in sound . Friend of mine says tubes aren't made as good as they were . Is that why us want to change them every ur?
I've always been very hesitant to buying tube-amps because of of the livespan of tubes... since they are very expensive.
They are great for guitar amps, other gear doesn't really benefit from harmonic distortion. Usually they are too big and loud to play at optimal volume. Attenuators affect tone, amp/speaker interactivity and shorten tube life, so a small single ended guitar amp can be the best choice.
Under normal design range and operating loads of the normal condition preamp tubes (12au, 12ax, etc), you may replace them in 3 to 5 years for daily usage of 3 to 6 hrs a day, I anticipated. The "failure stage" could be longer.
As far as the various tubes that I use, they range in lifespan between 2500 and 5000 hours of use, as per the manufacturer's data sheet. Now, as far as when the sound degradation becomes apparent/ noticeable I'd have to say depends on your own ears.
It really depends on how much you use them, what their application is and the quality of them. I can’t talk for hifi amps but I found with guitar amps that the power section ones only last about a year, preamp ones can last several years .
I agree ,I was lucky, mine lasted about 21/2 yrs to last sat night last song of night and Puff! 🤣
My ex band mate plays regularly with two bands. His Fender DeVille 212 has hadoriginal tubes +20 years and still working just fine. Only maintenance has been replacing one input jack and one fuse.
What was the amp of your friend? :)
and yet I have some tubes from the fourties that still work fine.
this
I had my 7 years old high end tube amp checked last week and they said they are in great condition and there is no point in changing. I'm using this amp everyday for many hours.
Grobbekee seriously?
awdadw adwad my 11 year old tubes still work
This the difference between crappy new tubes and vintage tube I have 6l6s that test stronger than brand new jjs and this kinda the norm lol
Aw man.. I don't know what input stage and output stage means.. would somebody help me out with that? Tried googling it, nothing clear came up.
In puts are PC's, turntables, streamers ect. In my mind an output is a TV or a set of speakers but I don't know what input stage or output stage means in this context.
Dang, I've had the same factory tubes in my Mesa Boogie Strategy 500 since 1994 when I bought it new. I'd probably change tubes out more often if it didn't cost $400 a pop.
Depends on the amp. 10-15 years in a Bob Carver.
in the 60's you could go to the corner drug store & put them on a tester....my guitar amp may need some new ones ...I am hearing a sizzle or maybe there is a lose cover or something.
I’m a guitarist so my needs may be different. My amp uses tubes, 12ax7s and EL34s. After replacing Russian and Chinese tubes far too often I took the plunge and bought NOS and as-new used Mullard tubes from England. The NEWEST of these is a mid seventies NOS set of EL34s, the oldest is a 12ax7 date coded August 1960, same as me. They all work and test better than brand new reproductions. Perhaps the need to replace annually reflects the poor quality of modern tubes rather than the longevity of old school quality control. Maybe I’m just hard of hearing. :)
take it from a guitarist. tubes can last 15 years or 15 months, or 15 weeks. really depends on your luck of the draw and how hard and often you use them, and whether you let them warm up or not. how often should you replace them however is a much easier question to answer: once a year is a luxury! once every two and youre doing really well. once every 5, well, youre getting your moneys worth at least.... if you cant do them every year or two, then the answer is simply as often as your budget permits it
Well, if you have a nice tube amp like the BHK, I assume you have that luxury. xD
Just think of them like incandescent light bulbs, really. They can last a lifetime if they happen to have flaws and never have any stress on them (power cycles) or they could go out in a week or two for no apparent reason.
imantisocial my tube seems to be working still after 11 years even though I never turn my amp off
I agree, it's the cold to hot transition that does most of the damage.
I get around 5 years on a set of XF1's in my 8B. I get around 2 years using the reissue Mullard EL34's by New Sensor. Not as good as the originals but easily the best non NOS version for my gear - even better than Winged C.
Annual tube changeovers are excessive unless you run them nearly constantly. Not to mention the cost! Of course, your IRS towers are highly resolving and require a lot of power, so maybe it might be worthwhile in that case.
what is not being made clear is....hours of service. Tubes are kind of rated like a light bulb.....how many hours it should be expected to burn....BECAUSE they both use a thoriated tungsten filament...light bulbs and vacuum tubes. SO if his listening room system is constantly ON...it accumulates hours. Tubes generally are good for several thousand hours.....and if they have a good vacuum and seal...they could go longer. Also factored in is the on/off cycle which could eventually cook off the coatings on the metal parts within the vacuum....so there are other factors for wear and tear.....remembering that cycling on/off also imparts heating and cooling thus expansion and contraction.....so there are basic factors hiding in front of your nose in the matter. BUT in a perfect world they theoretically could last indefinitely. The designed obsolescence factor is the actual vacuum in the glass.....as that can be manipulated as with light bulbs...the science was so precise in manufacturing.......profits depend on repeat sales based on a cycle of longevity and controlling the aspects of longevity.
to illustrate....the edison light bulb in some firehouse out in california has been burning for 100 years.........as it was produced prior to the concept of designed obsolescence in business. So basically it came off the assembly line with an extremely good vacuum and has been permitted to burn steady and not been subject to adversity's.....like extreme vibrations and on/off cycles......its been in a steady state. You definitely wouldn't find a modern chinese made light bulb that would ever last that long ......since they are not made in america these days......and they are made post era of designed obsolescence in the business models.......you might be lucky to get a month or 2 out of a chinese light bulb.
Dang ... if it’s 1-1.5 years then purchasing good NOS tubes like Pope 6SN7 will not make sense anymore 😢
Paul,
sorry but there was no threshold at where you explained it.
Why not ?
He clearly said he doesn't have much knowledge of tubes. Clean your ears.
You can tell when preamp tubes are going when the sound gets hissy and lacks dynamics. You know it takes alot longer for a transistor amp to warm up and sound good than a tube amp. Some tubes will last a very long time like some Telefunkens while chinese made tubes are good for about 6 months.
How many Nipper's do you own. I have seen 2. I have a bunch of Nippers too.
Hey Paul - Good stuff. But, if you're not sure how long your valves will last, just ask Nipper!
don't tubes very from brand to brand? i noticed that odd brand tubes don't last quite as long as Westinghouse or sylvania
Good vid at last
nos last longer. at least 3 times longer than the modern tubes.
Fell asleep waiting for the answer
I understand why you replaced all of the tubes, kind of a shotgun technique. There's a really good chance that only one tube was failing and quite a bit of detective work would have been required to find out which one.
I've changed mine once in the last 12 years on my hot rod deville.... Just because it stopped working
💪💪💪
You’re right in that tube slowly degrading performance and it’s very deceptive and hard to see but tubes have a very definite life expectancy especially power tubes my holy Grail of the RCA tubing guy Manuel it estimates 1000 hours of full power before the amount of electrodes are burned off by the The cathode decreases to an amount that is unsatisfactory to meet the specs power tubes 1000 hours is usually considered to be a year is used for hi-fi same with stylus is on cartridges once a year low level tubes is well they asked seven for example is not wearing out it will lose the seal as you say but otherwise they last a long long time
Paul,Ask anyone how neo speakers sound in a guitar amp.Everyone says the same thing"Their lite".
so my tubes from 68 are no good..
“Once a year” is a lame answer. It’s based on hours, and on how hard the component drives them. About 5000-10000 hours is the average.
about a year service life is a common design flaw. I have full scratch builds running over 10 years now, using same tubes....
Too bad no one listens to me........
He looks like a scientist
Huh. Won't work on a satellite mission that needs to last 20 years or more.
Paul is like the grandpa' at the Xmas dinner when you ask him a question, then you're half way through the dinner when he finally gets to the answer 😂 in the mean time you already forgot what the question was😂
retubing annually is insane
Once a year? Than your equipment is really bad and run your tubes too hard. Primaluna runs 10 years on a set.
Not mine. Had one go bad within a year. Replaced them with a set of Mullard platinums and one of those toasted in about a year.
I disagree with you on 2 things. first, you don't have to replace tubes once a year. That's like changing the oil for your car daily. Second: Pure tube amps sound much better than a hybrid amp. I have tried both.
I'm not an expert on this stuff by no means, but if you have to replace your tubes every year you must have some pretty shitty tubes. Or maybe you just leave the amp burning 24/7 for a year.
Tube expert?
Huh???
If people keep buying 'em..they'll keep making 'em..if they don't , then they will stop making them and then we all go over to solid state...
7:04
I worked on a Radar site, 1000s of tubes in the rack mounted equipment. Nothing was ever turned off. Tubes lasted a year.
It’s way more convoluted than Paul’s answer regarding tubes. It depends on the quality of tubes, listener, system & parameters the tubes are operated at, age & hours on tubes. Also, with tubes there is always an upgrade path.
Just say it tubes are not worth the headache 🤕 for the money,I listen to a lot of music every day and loosing quality of sound slowly over time is not what I want to put my money into,never for me
I can swear their is a Klipsch heritage headphone amp just under the left side for the monitor! Can anyone agree with me or am I just seeing things.
Under the monitor... looks more like a Focusrite 2i2 interface.
"Burn in overnight", you said to burn in your solid state products for week. Not nessasary in my opinion.
they last as much as you use them i guess?
🙄😅😜😂😂😂
Wait, you just opened an envelope. But there’s no addresses or postmark. So it’s just theatrics?
don't skimp on preamp tubes if you care about your tone ,your money and your sanity.
modern preamp tubes(china
ussia \slovakia) last up to 2000 hours .nos preamp tubes last 10000 hours or more .
the fact that audiophiles put cheap (10- 40$ each)russian or chinese made components in their high end preamp is crazy since:
1. they sound so bad compared to nos. do an a\b comparison trust your ears( not paul in this case he is marketing his gear which uses russian tubes as the heart of the amp )
2. they don't last as long as nos. you have to worry about it every year and buy tubes again.
paul uses 40$ a piece new sensor genalex tubes (all russian tubes are made in the same factory these days sovtek genalex eh mullard ri brimar tung sol groove tubes all sovtek with nicer labels and boxes)which costs 40$ .even though proper nos tubes costs 2 or 3 times that price ,they sound better ,last longer and keep you free from stupid worries you shouldnt have with high end gear. let's say you have only 5 tubes so 200$ a year for every year of uncertainty and harsh sound or about 500$ for 5 years of sweet sound (so say audiophiles in the last 70 years) and peace of mind. you can buy nos from reputable stores and dealers :upscale audio thetubestore tubedepot etc
test the tubes once a year! what about hours of use?
...when they fail.
Stupid question. Stupid answer.
Bs meme.
wah your tubes only last a year is only about 2000 hrs n the sound turn bad n lose it magic this is not good for business maybe your engineer have turn up the bias too much that why the tubes only go for 2000 hrs n they start to turn bad
Who started calling them tubes. They are called valves because they act like a valve in an electrical circuit.
Change them once a year?
No. Absolute nonsense.
*test* them once a year and bias them every 3 to 6 months after initial burn in.
If you're having to change your tubes out once a year, you need to check your gear. Even cheap tubes last longer than that.
Dude, the question was how long do tubes last? WTF 3:29 I'm bailing out. Still have no idea what the answer is in your opinion but I know about 500 other things I could care less about.
He shouldn’t talk about things he doesn’t know anything about! Once a year? Yeah right......if you run it 24/7 maybe....
Tubes sound way better sorry to say but I swear by this.