I just watched this again, and I love the methodical, never give up nature. You kept following the steps, even a couple of false steps, but tracked it down. Nicely done and informative to watch!
"Could it be... sniff, sniff, sniff - no, it's just white powder" You had me laughing out loud at my desk - I didn't see that coming from you. Nice troubleshooting - I enjoyed following along.
Made me laugh too "could it bee..sniff sniff, nah" 😂 Buddy was out for nosecandy like bloodhound 😁 Btw, I've heard from other amptechs that thoose amps got an serius temp problem and often need to get fixed due to that.
I'm a certified Fender amp tech . Upon seeing this problem , I would've resoldered most of the pads on all of the boards and replaced most of the electrolytic caps . Expescailly the ones that have anything to do with the B+ voltage. But Stuart is a great tech. I tip my hat to him.
Hi Tim thanks for the advice. My problem is always money (i.e. trying not to overcharge the customer). I usually just fix the problem and check for anything else really obvious and alert them of that to see if they want to do the work.
Having worked on a fair few of the Hot rod series, they all have the same common faults. Mk 1 through to mk5, none of the issues have ever been resolved!! Ceramics resistors flat against board causing over heating and failure. The worst filter caps on earth that always leak and fail. Solder joints on board mounted sockets crack and fail. Drive switch on amp is cheap and fails. When all of these issues are rectified, these amp are actually very good reliable units. I own and use a 4x10 HR deville. It has been totally reliable since upgrades in 2010.
@@rgbplumbinghilton I also use a HR Deville 4x10. It's a great sounding amp and stays clean on the clean channel even at higher volume. The issue I am having recently is loud buzzing on the overdrive channel. Is this a common problem with a common fix?
Well done chasing down the issue. I've been a tech for over 40 years and have had issues like this that respond to heat and cold. I was pleased to see you use this technique. Most don't know about it. The same crackle etc has often turned out to be a temperature-sensitive part or many times a dry solder joint. I suspect you'll get the amp returned one day for a repeat of the issue and you'll actually discover that the ribbon cable has a dry solder joint. When you bent the ribbon the crackle stopped. It wont last forever. I really did enjoy your methodical approach and respect you skill. Im no good with tubes only semi's.
Stuart!! I'm relieved to see you well, and in good shape. Much time has passed since your last installment, I had feared the worst. This series of amps are poorly designed, and not conducive to servicing. It has not changed since the inception of the Hot Rod series. This really tested your patience. I would have chucked it out he window. I am happy that it got sussed. Cheers to you, and as always, stay safe and clear from harm's way. Speak soon.
Thanks Alex. YEs I went a bit quiet after Christmas as I was enjoying being less busy! More vids on the way soon. I try to do about one a week if poss.
What a fabulous series of videos! I have a rudimentary knowledge of electronics, and your superb step by step fault finding investigations and commentary on your thoughts behind your approach is really inspiring and has helped me put many things in context! I especially like the fact they you be deliberately left in some rabbit holes you went down (and why - I was once advised that sometimes you learn more through errors and mistakes). Thanks so much 😊
I’ve have a Blues Deville that the ribbon cable had actually broken on one of the leads right where it meets the soldering pad . Easy fix but a beast to find !!! Good Work Sir!!!
Very clever technique to use warm humid breath to reveal breakdown conductivity issues. This is the first of your videos I've seen and I'm a new subscriber now. It's always so much more informative to reveal the struggles and mistakes of a difficult task. Please keep it up and Thanks!
@@stuartukguitarampguy5830 Still trying, things keep shifting. Used to be noisy with only the power tubes (EL84) installed. Now it's quiet in that configuration, only noisy when the PI is installed. I think it's a bad solder joint, but I can't find it. Prodding, wiggling, no joy. Will try freeze spray next.
I had a similar sound and resoldered the tube pins (cold solder joints) & no more problems. On this one, all that corrosion indicates a spill… cleaning board maybe a good first step.
Thanks Stuart , I really enjoy watching your investigations , I have a HR Deville I’m fixing up, I’m trying to eliminate a slight high pitched buzz coming from the board area when I turn standby to on , (almost like the noise a Cicada bug makes)
@@stuartukguitarampguy5830 The board definitely seemed overly sensitive , think I’ve got it licked now, noticed someone else had been in there , found some nasty joints and a damaged trace . Thanks 🙏
I picked up a Hot Rod Deluxe this past weekend. I knew I was going to have to repair a reverb problem, but after the deal was done is when I noticed one of the power tubes wasn’t heating up. A quick look at the tube socket board revealed one pin was missing solder. I wondered if that tube socket ever worked. Well soldering the one pin got the tube working. Then came the crackling. 😂 I just finished reflowing solder on all the tube socket connections and no more crackling. I had a reverb tank lying around and it revealed the old tank was broken. Got that on order. I’ve ordered a kit from an eBay seller to address other regular fail components and I also found someone selling a black-backed controls faceplate to hide the rusty chrome face. I also noticed small traces of white powder in my amp. Hmmm. As I always have to do with Fenders, I ordered a new snap-in audio taper volume pot. I don’t understand why Fender uses linear volume pots, but whatever, I’ve just come to expect it. As always, another wonderful production on troubleshooting techniques. Thank you!
Whenever I get a crackling or noisy 2nd hand amp thats old and dirty, i always clean the pots, jacks, tube sockets, and board first. Works 80% of the time
Hi Frank, yes I learned something here and would be quikcer to clean the board - but it looked so immaculate I was fooled. Still not 100% sure what actually caused this problem.
@@stuartukguitarampguy5830 , I don't mean to sound harsh, but did you get the definition of "immaculate" from Webster or from Ambrose Bierce's "Devil's Dictionary"? from . The rusty, crusty control panel, and the rusty, crusty lower lip of the chassis (near the tubes) were clues that you completely missed. This thing quite obviously had a beer or soda spilled into it (bottled water would not have left much residue nor caused that much corrosion). I would have scrubbed those circuit boards and cleaned the tube socket contacts, and examined/resoldered the connections, *FIRST*.
Amazing how you struggle with this beast 🙂Your videos show expertise and experience and demontsrate how much you know about valve amplifiers. Respect! The loud crash sound in this video reminds me of a repair of a guitar amplifier many years ago I did for a friend. He had a guitar amplifier with a MOSFET output stage which did not give any sound at all. But all the time when I turned the volume knob (and only then!) extremely load crashes could be heard in the loudspeaker, exactly sounding like in your video. I sat hours in front of the amplifier and couldn't find the reason. Then I noticed that the wiring from the output stage to the loudspeaker was very close to the input signal routing. They were only a couple of centimeters apart from each other. And when I increased the distance between them considerably, the amplifier awoke from its "sleeping beauty" slumber... So, my idea (just an idea...) is that HF oscillation could be the cause of the loud crash sound. The unshielded ribbon cables (especially when folded and bent close to the pins of valves !) create some unwanted feedback via stray capacitance and make the valve amplifier walking on the edge of instability. And because the shielding backplate is removed, whenever you come the ribbon cables close with your fingers, hands or your face, you increase the unwanted capacitive coupling from the amplifier's output (loudspeaker wires, power valves, etc.) to the ribbon cables or other internal circuitry and initiate oscillation. Moving away the ribbon cables from the valves' pins towards the grounded backplate would eventually help to prevent HF instability, provided the corrosion is removed from the backplate connections. Warm greetings from the romantic Black Forrest in South Germany 🙂
@@stuartukguitarampguy5830 yeah sometimes they drink beer. I have a fender hot rod deluxe 1 that has a hum. If I go to the distortion channel it goes away, but if I hit the more distortion button it comes back. Clean has the hum as well. Any ideas? My plan was to change tunes and learn to solder to replace the 500v IC capacitors.
@@Beezi. That's an odd. one. A big culprit on these amps are the HT smoothing capos, look for leakage. But I would have thought that would give hum no matter what you selected.
@@stuartukguitarampguy5830 I was testing a few resistors that people say go bad and found a 100k resistor by the phase inverter tube that was testing at 215k. I assume that is causing issues and will replace.
I've been working on one of these for a month, very similar issue. I had already narrowed it to the power section as I wasn't hearing the crackle when using the pre-amp out. My logic ended up taking me through the same sections as you and not yielding any results. So finally i took a toothbrush to the tube connectors...Lo and Behold! The crackle vanished. Nice to know pros with years of experience on me have the same runarounds. Now, any idea where I can get replacements for these absolute garbage cable ribbons?😂
Glad to see you back Stuart! Very interesting video there. I noticed a Peavey sat behind you too! I'd be interested to see what that's about, I have a 6505 here that likes to pop V3 just randomly that I've not yet been able to track down why. I've never once thought to do a breath test on boards, very funny but actually very useful tip!
Hi Jon. Yes that's a cool tip isn;t it? Great for HV arcing issues. Poping V3?? Is that the phse splitter? Quite rare for a preamp valve to go more than once.
@Stuart ukguitarampguy I'll correct myself. It is third from the end but in the 6505+ it's a V2 tube active in the lead channel stage. The layout is really odd in those Peaveys. It will be fine for ages (weeks or so, approaching 30-40 hours or so) and then one day pop and it's gone. Clean will still be fine but the lead channel will be dead. I've been through the amplifier with a multi and really don't see anything wrong. Cleaned the sockets, been through the switching circuit in case anything was arcing, found nothing. I think it's one of those things that I have to have the thing apart when it happens to really figure what's going on. One of those fixes itself problems until it happens again. I have a set of Tung Sol in there again, wondering if it was a case of dodgy JJ tubes. I was using ECC83s and have since changed to the 12AX7WA. I have had a few of those JJ EL34s go down in my 100w Marshalls (almost spilled my coffee when I heard you say it too) so wondering if it's just another thing quality wise that JJ are suffering. I'll report back if the Tung Sols go pop though!
Had a Blues Jr with the same crackling issue on the bench. Using your advice and blowing on the junction between the ribbon cable and tube PCB also temporarily got rid of the crackling noise.....but..... The owner had changed the input jack and his solder joints on the PCB were not shiny. When I reflowed them they made a crackling sound. I asked the owner what solder he had used for the repair and it turns out he had used PLUMBING SILVER SOLDER! Removing the plumbing solder and then using normal electrical solder SOLVED THE PROBLEM. Who would have guessed???!!!!
I enjoyed the video, thanks for taking me on that troubleshooting journey! Learned a lot. Is there a reason you don't use an oscilloscope and follow the noise back from a source? (starting at the speaker or the input of the power section on this one)
Hi Frankie I'm glad you enjoyed it. I try to avoid using the scope unless I get really desperate! Most problems can be found using fairly simple diagnostic methods.
Great, detailed, forensic diagnostic journey 🙂 Appreciate your 'working backwards/thinking forwards' methodological approach in order to home in on the issue. - The 'grounding out' technique on nodes to isolate issues - guess that I would normally be wary of shorting out anything in a valve amp in case everything went Magic Smoke BANG! - But yeah, if the node is at *signal* level.. - guess, you can always short it out to test..' - The freezer spray thing I've come across before, (& the hot-air gun) but the moist-air breath straw was a new one on me 🙂 Also liked the shielding with bits of paper - hehe - (might the likes of fancy 'Kapton' tape offer any advantage?) - Anyways, you, the amp, (and us viewers) got there in the end.. well done 🙂
Thanks Gervais. I've got an Orange Matamp OIRST on the bench at the moment with a hum problem. Literally nothing I do changes it by so much as 1% so I'm completely stumped!
@@stuartukguitarampguy5830 Hey - Good luck with all that :-) - have recently been looking into the concept of 'differential scope probes' - might they be of any use in such a situation? - buut... they seem V. expensive: ua-cam.com/video/OZDijMDHmtI/v-deo.html - anyone know of any cheaper/DIY alternatives? ----------------
1am and I've woke up and I'm wide awake. What could be better than a Stuart amp-whodunnit. The crackle might have got away if it wasn't for the pesky toothbrush 😆
Well, wasn't that fun! If it was a PTP amp, it wouldn't have needed that repair. 😉 Thanks for the video. I only found one schematic and it didn't match the boards you were working on so I couldn't follow along that way too much. But I will say at one point, I was thinking volume pot, solder joints. I didn't see anything above that would leak on the board so I wonder what it could have been?
Hey there i have a Hot Rod De Ville 4x10 USA iv replaced the light bulb and it is still verry dim at first it was normal but now you can nearly see if its on any clue as to what that problem is thank you
I've a silicone straw for blowing warm moist breath onto boards / components/ I had an amp in which hum was bad and breath on nearly all tube sockets made it much worse. It was a 1965 Fender Deluxe Reverb and I wanted to preserve the original sockets. I removed them all, scrubbed them with dish soap and water, and soaked them overnight in isopropyl alcohol then blew them dry with heat. No more hum! My theory is that someone used a conductive product to "clean" the tube sockets.
Thts what mine sounded like just before there was no sound at all . But what was the putrid burning smell tht was with it .I took the chassis out but cldnt see anything black or discolored. What might tht be sir . Thkx
Hi Stu, SNAP! I've got a Deluxe on the bench that has intermittent 'Drive' channel, took the main board out and reflowed every joint around V2 and I think it's fixed, but it's comes back intermittent again - f*ing Fenders!
It's a nightmare when that happens. I really hate it when a customer takes an amp away (usually having driven a fair distance) and contacts me next day saying "Err... it's back...". Aaaagggh!
@@stuartukguitarampguy5830 story of my life! Finally tracked down the fault to the relay K2, intermittent contacts, took about 3 blooming hours to trace :/
I had the similar cracking problem but not that loud, I shake the inverter tube effect the cracking sound so I just resoldering the tube socket and others soldering points around it and noise just gone.
Hi Gervais. I have a thing that I only get the scope out as a ;ast resort. 9% of faults can be found by good troibleshooting. But I certainly use it when I need to and get desperate!
@@stuartukguitarampguy5830 thx for reply - how aware of issues might one need to be in terms of low-impedance / shorts when test- shorting nodes to ground (esp. in HV valve circuitry?)
@@stuartukguitarampguy5830 Oh - think I meant like the difference between a 'low current' & 'high current' short - one diagnostic, the other perhaps fire-starting.. 🙄
@@gervaiscurrie6675 , I have a test-probe cable with pointy probes on both ends, for shorting signal to ground or jumpering around suspect parts ---- If I was a newbie I would make sure to have a fuse in line between those two probes, but I've been doing electronics for over 50 years so it isn't strictly necessary for me. Ask me again in 5 years if I've installed an in-line fuse yet, because of my hands getting shaky as my arthritis worsens.....😖
Those crackling/popping problems are always simple to fix, but complicated to find. Literally anything inside the amp can cause that problem so it turns into a wumpus hunt. I always start by carefully inspecting every solder joint- 90% of the time I can find one or more that are bad. It doesn't always fix the problem, but any bad joint will cause a problem anyway. Other than that, it's a tedious guess/test/check until the problem goes away.
I work fixing High End Audio for 30 years. Most of the times I found resistors or tubes making cracking noise. But capacitors , solder joins or PCB inclusive can make the same noise. Best Regards.
It’s videos like this that really make me think twice about sitting directly in front of the 2x12 that’s hooked up to my JVM 😂 Really don’t fancy 100watts of that racket blasting in my face when something inevitably goes wrong… The joys of valve amp ownership!
I wonder if something was spilt on that amp. Which would possibly explain the surface corrosion and also the weird powdery stuff between the back panel and chassis. And of course of any liquid had got on that valve board that could also explain the crackle. Either that or it’s been stored somewhere where water is leaking in.
Hi Your comment is not not attached to your original comment which I cannot find, Please carefully explain the issue you are having and I'll se what I can do.
@@moGear6253 If everything else is ok, then I suspect the actual connections to the back of the bulb. Try moving them around a bit to see if the lamp comes on solid.
thank you ill try looking at that socket it's dim all most noexzistance lol yup i all so noticed that sitting right beside the amp i got a lot of humming so i relocated my amp ???
Hard work Young Stuart!! Would NEVER buy one of these damn amps! Always a bloody problem and extremely difficult to work on!! (I think they are actually made to be that way!!) 5*****
@@stuartukguitarampguy5830 - as my Dentist seemed to say to me as he was taking me under his Gas.. "Relax, Sir, : what Wife or Girlfriend would not come out delighted with your 'New Man Look' as you come back fitted with a full set of matched NOS Russian EL34 mouth-pins..." *Shudder" 🙂 -Look fwd to more interesting vids - Best,
Amazing that Fender continues to fleece it's customers with cheap ribbon cables,junk caps that will prematurely leak,and component placement that will burn up the board...at least they threw in some of Columbia's finest for the tech 🤪
TAKE IT APART FIRST!! PLEASE 90% of crackle is bad joints you cant see when its together, plus those bad caps are effect not cause, so look UNDER. Take a few screws out PLEASE : > p
Nice to see you back Stuart .. I thought you might have been abducted by aliens in this mad and illogical world we live in . A bit like the illogicality of those faults you discovered and fixed. I think, I'd have thrown in the towel as I don't have your patience and determination. What a sad state the amp is in.. How long does it take to wipe a cloth over it ? They're nearly a £1,000 to buy new. Stay well and hope to see you soon..
If anyone is still struggling with this, make sure your phone or any other device isn’t on/right next to your amp, i used to keep my phone on it and that was the problem.
Intermittent issues are time consuming to start with and to throw in a few leaky capacitors for good measure..our customers are lucky us old amplifier technicians enjoy the challenge cuz Sure isn't for the Money.
@@stuartukguitarampguy5830 right on, thanks man. Just got gifted a hot rod deluxe from a friend... Old roomie left it behind so I lucked out on a decent project. Noticed my caps are leaking and a lot of reviews say they're cheapo so I wanted to find a decent enough upgrade.
I just watched this again, and I love the methodical, never give up nature. You kept following the steps, even a couple of false steps, but tracked it down. Nicely done and informative to watch!
Thanks Richard!
I had a Dr. Z last week that was microphonic everywhere. Finally pulled the input jacks and found no star washers.
"Could it be... sniff, sniff, sniff - no, it's just white powder" You had me laughing out loud at my desk - I didn't see that coming from you. Nice troubleshooting - I enjoyed following along.
Thanks Bob!
Made me laugh too "could it bee..sniff sniff, nah" 😂
Buddy was out for nosecandy like bloodhound 😁
Btw, I've heard from other amptechs that thoose amps got an serius temp problem and often need to get fixed due to that.
I'm a certified Fender amp tech . Upon seeing this problem , I would've resoldered most of the pads on all of the boards and replaced most of the electrolytic caps . Expescailly the ones that have anything to do with the B+ voltage. But Stuart is a great tech. I tip my hat to him.
Hi Tim thanks for the advice. My problem is always money (i.e. trying not to overcharge the customer). I usually just fix the problem and check for anything else really obvious and alert them of that to see if they want to do the work.
Having worked on a fair few of the Hot rod series, they all have the same common faults. Mk 1 through to mk5, none of the issues have ever been resolved!!
Ceramics resistors flat against board causing over heating and failure. The worst filter caps on earth that always leak and fail. Solder joints on board mounted sockets crack and fail. Drive switch on amp is cheap and fails.
When all of these issues are rectified, these amp are actually very good reliable units. I own and use a 4x10 HR deville. It has been totally reliable since upgrades in 2010.
@@rgbplumbinghilton Hi Richard yes I've seen all those problems too.
@@rgbplumbinghilton I also use a HR Deville 4x10. It's a great sounding amp and stays clean on the clean channel even at higher volume. The issue I am having recently is loud buzzing on the overdrive channel. Is this a common problem with a common fix?
@Richard56er I would start by taking the board out check for dry joints or just reflow the whole lot.
I love videos like these where he actually troubleshoot his way to success unlike other technicians who seem to create and solve their problems
Thanks Patrick that's exactly what I'm aiming for.
Well done chasing down the issue. I've been a tech for over 40 years and have had issues like this that respond to heat and cold. I was pleased to see you use this technique. Most don't know about it. The same crackle etc has often turned out to be a temperature-sensitive part or many times a dry solder joint. I suspect you'll get the amp returned one day for a repeat of the issue and you'll actually discover that the ribbon cable has a dry solder joint. When you bent the ribbon the crackle stopped. It wont last forever. I really did enjoy your methodical approach and respect you skill. Im no good with tubes only semi's.
Thanks Stephen.
Stuart!! I'm relieved to see you well, and in good shape. Much time has passed since your last installment, I had feared the worst. This series of amps are poorly designed, and not conducive to servicing. It has not changed since the inception of the Hot Rod series. This really tested your patience. I would have chucked it out he window. I am happy that it got sussed. Cheers to you, and as always, stay safe and clear from harm's way. Speak soon.
Thanks Alex. YEs I went a bit quiet after Christmas as I was enjoying being less busy! More vids on the way soon. I try to do about one a week if poss.
This was one of the most interesting amp repair videos I've ever seen! This I will save. Thanks!
Many thanks!
What a fabulous series of videos! I have a rudimentary knowledge of electronics, and your superb step by step fault finding investigations and commentary on your thoughts behind your approach is really inspiring and has helped me put many things in context! I especially like the fact they you be deliberately left in some rabbit holes you went down (and why - I was once advised that sometimes you learn more through errors and mistakes). Thanks so much 😊
Thanks I'm pleased you are enjoying them!
I’ve have a Blues Deville that the ribbon cable had actually broken on one of the leads right where it meets the soldering pad . Easy fix but a beast to find !!! Good Work Sir!!!
Ooo nsaty. Well done for finding!
I admired your patience through the troubleshooting process. A very good lesson.
Thanks Barry
Very clever technique to use warm humid breath to reveal breakdown conductivity issues. This is the first of your videos I've seen and I'm a new subscriber now. It's always so much more informative to reveal the struggles and mistakes of a difficult task. Please keep it up and Thanks!
Thanks I'm pleased you are enjoying the vids!
Loved your work process to hunt the source of the noise
Another enjoyable watch - thanks! Following along with your fault finding logic, including dead ends, is very interesting.
Thanks Greg
I’m chasing a similar problem on a very different amp, but the thought process, and techniques you used have been very helpful. Thanks!
I hope you get yours sorted!
@@stuartukguitarampguy5830 Still trying, things keep shifting. Used to be noisy with only the power tubes (EL84) installed. Now it's quiet in that configuration, only noisy when the PI is installed. I think it's a bad solder joint, but I can't find it. Prodding, wiggling, no joy. Will try freeze spray next.
@@simbotist Ok good luck!
I had a similar sound and resoldered the tube pins (cold solder joints) & no more problems. On this one, all that corrosion indicates a spill… cleaning board maybe a good first step.
Great thanks.
Wow. I thought the crackling were the voices in my head. Thanks for another great and fun video.God Bless from the US.
Seeing that the amp was definitely in a moist environment, possibly some moisture in the tube socket may have also played a part in it. Great video.
Thanks Sean glad you enjoyed it.
Thanks Stuart , I really enjoy watching your investigations , I have a HR Deville I’m fixing up, I’m trying to eliminate a slight high pitched buzz coming from the board area when I turn standby to on , (almost like the noise a Cicada bug makes)
Hi John. Does it change when you flex the board? It COULD be an HT arc - very hard to diagnose over the net!
@@stuartukguitarampguy5830
The board definitely seemed overly sensitive , think I’ve got it licked now, noticed someone else had been in there , found some nasty joints and a damaged trace . Thanks 🙏
well done.@@johnmiller3804
Good to see you again .
Thanks! I took a bit of a break plus had a slew of not very interesting amps/faults.
Wow, that was a pesky one..! Love the fault diagnosis, lots of tips and new ideas..Great vid, take care..Ed..uk..😊
Thanks Ed.
I picked up a Hot Rod Deluxe this past weekend. I knew I was going to have to repair a reverb problem, but after the deal was done is when I noticed one of the power tubes wasn’t heating up. A quick look at the tube socket board revealed one pin was missing solder. I wondered if that tube socket ever worked. Well soldering the one pin got the tube working. Then came the crackling. 😂
I just finished reflowing solder on all the tube socket connections and no more crackling.
I had a reverb tank lying around and it revealed the old tank was broken. Got that on order.
I’ve ordered a kit from an eBay seller to address other regular fail components and I also found someone selling a black-backed controls faceplate to hide the rusty chrome face. I also noticed small traces of white powder in my amp. Hmmm.
As I always have to do with Fenders, I ordered a new snap-in audio taper volume pot. I don’t understand why Fender uses linear volume pots, but whatever, I’ve just come to expect it.
As always, another wonderful production on troubleshooting techniques. Thank you!
Sounds like you've done a great job there Don. Well done.
Like a police procedural drama! Great video, Stuart, as always.
Evenin' All, now what seems to be the trouble here...
Whenever I get a crackling or noisy 2nd hand amp thats old and dirty, i always clean the pots, jacks, tube sockets, and board first. Works 80% of the time
Hi Frank, yes I learned something here and would be quikcer to clean the board - but it looked so immaculate I was fooled. Still not 100% sure what actually caused this problem.
@@stuartukguitarampguy5830 , I don't mean to sound harsh, but did you get the definition of "immaculate" from Webster or from Ambrose Bierce's "Devil's Dictionary"? from . The rusty, crusty control panel, and the rusty, crusty lower lip of the chassis (near the tubes) were clues that you completely missed. This thing quite obviously had a beer or soda spilled into it (bottled water would not have left much residue nor caused that much corrosion). I would have scrubbed those circuit boards and cleaned the tube socket contacts, and examined/resoldered the connections, *FIRST*.
Where can I get one of those CTTs (Certified Test Toothbrush)? I need one for my kit. :)
Hmm, I feel a sideline coming on....
Amazing how you struggle with this beast 🙂Your videos show expertise and experience and demontsrate how much you know about valve amplifiers. Respect!
The loud crash sound in this video reminds me of a repair of a guitar amplifier many years ago I did for a friend. He had a guitar amplifier with a MOSFET output stage which did not give any sound at all. But all the time when I turned the volume knob (and only then!) extremely load crashes could be heard in the loudspeaker, exactly sounding like in your video. I sat hours in front of the amplifier and couldn't find the reason. Then I noticed that the wiring from the output stage to the loudspeaker was very close to the input signal routing. They were only a couple of centimeters apart from each other. And when I increased the distance between them considerably, the amplifier awoke from its "sleeping beauty" slumber...
So, my idea (just an idea...) is that HF oscillation could be the cause of the loud crash sound. The unshielded ribbon cables (especially when folded and bent close to the pins of valves !) create some unwanted feedback via stray capacitance and make the valve amplifier walking on the edge of instability. And because the shielding backplate is removed, whenever you come the ribbon cables close with your fingers, hands or your face, you increase the unwanted capacitive coupling from the amplifier's output (loudspeaker wires, power valves, etc.) to the ribbon cables or other internal circuitry and initiate oscillation. Moving away the ribbon cables from the valves' pins towards the grounded backplate would eventually help to prevent HF instability, provided the corrosion is removed from the backplate connections.
Warm greetings from the romantic Black Forrest in South Germany 🙂
its corroded around that area too so my guess was a beer spilled over the back and put a film on the board. great video.
Are you implying that guitarists drink beer from time to time? I vicious slur.
@@stuartukguitarampguy5830 yeah sometimes they drink beer. I have a fender hot rod deluxe 1 that has a hum. If I go to the distortion channel it goes away, but if I hit the more distortion button it comes back. Clean has the hum as well. Any ideas? My plan was to change tunes and learn to solder to replace the 500v IC capacitors.
@@Beezi. That's an odd. one. A big culprit on these amps are the HT smoothing capos, look for leakage. But I would have thought that would give hum no matter what you selected.
@@stuartukguitarampguy5830 I was testing a few resistors that people say go bad and found a 100k resistor by the phase inverter tube that was testing at 215k. I assume that is causing issues and will replace.
@@Beezi. Yes definitely replace that. It MAY read correct once you actually desolder it.
I've been working on one of these for a month, very similar issue. I had already narrowed it to the power section as I wasn't hearing the crackle when using the pre-amp out. My logic ended up taking me through the same sections as you and not yielding any results. So finally i took a toothbrush to the tube connectors...Lo and Behold! The crackle vanished. Nice to know pros with years of experience on me have the same runarounds. Now, any idea where I can get replacements for these absolute garbage cable ribbons?😂
I, ok interesting. When you say tube connectors do you mean the valve bases?
Glad to see you back Stuart! Very interesting video there. I noticed a Peavey sat behind you too! I'd be interested to see what that's about, I have a 6505 here that likes to pop V3 just randomly that I've not yet been able to track down why. I've never once thought to do a breath test on boards, very funny but actually very useful tip!
Hi Jon. Yes that's a cool tip isn;t it? Great for HV arcing issues. Poping V3?? Is that the phse splitter? Quite rare for a preamp valve to go more than once.
@Stuart ukguitarampguy I'll correct myself. It is third from the end but in the 6505+ it's a V2 tube active in the lead channel stage. The layout is really odd in those Peaveys. It will be fine for ages (weeks or so, approaching 30-40 hours or so) and then one day pop and it's gone. Clean will still be fine but the lead channel will be dead. I've been through the amplifier with a multi and really don't see anything wrong. Cleaned the sockets, been through the switching circuit in case anything was arcing, found nothing. I think it's one of those things that I have to have the thing apart when it happens to really figure what's going on. One of those fixes itself problems until it happens again. I have a set of Tung Sol in there again, wondering if it was a case of dodgy JJ tubes. I was using ECC83s and have since changed to the 12AX7WA. I have had a few of those JJ EL34s go down in my 100w Marshalls (almost spilled my coffee when I heard you say it too) so wondering if it's just another thing quality wise that JJ are suffering. I'll report back if the Tung Sols go pop though!
Brilliant. Enjoyed that very much. Watched the video all the way to the end and its 2:00am on this side of the Atlantic , lol. *Yawn*
Hi Bob Glad you enjoyed it and sorry to keep you up!
Devil Breath😂.
Great honest video so far Stuart👌🎸
Thanks Mark I'm glad you enjoyed it.
Well done Mr Smith👌👍😊
Thanks MArk
Had a Blues Jr with the same crackling issue on the bench. Using your advice and blowing on the junction between the ribbon cable and tube PCB also temporarily got rid of the crackling noise.....but.....
The owner had changed the input jack and his solder joints on the PCB were not shiny. When I reflowed them they made a crackling sound. I asked the owner what solder he had used for the repair and it turns out he had used PLUMBING SILVER SOLDER!
Removing the plumbing solder and then using normal electrical solder SOLVED THE PROBLEM. Who would have guessed???!!!!
I wish people wouldn't 'have a go' themselves! It makes our lives a lot harder.
I enjoyed the video, thanks for taking me on that troubleshooting journey! Learned a lot. Is there a reason you don't use an oscilloscope and follow the noise back from a source? (starting at the speaker or the input of the power section on this one)
Hi Frankie I'm glad you enjoyed it. I try to avoid using the scope unless I get really desperate! Most problems can be found using fairly simple diagnostic methods.
Great, detailed, forensic diagnostic journey 🙂
Appreciate your 'working backwards/thinking forwards' methodological approach in order to home in on the issue.
- The 'grounding out' technique on nodes to isolate issues - guess that I would normally be wary of shorting out anything in a valve amp in case everything went Magic Smoke BANG! - But yeah, if the node is at *signal* level.. - guess, you can always short it out to test..'
- The freezer spray thing I've come across before, (& the hot-air gun) but the moist-air breath straw was a new one on me 🙂
Also liked the shielding with bits of paper - hehe - (might the likes of fancy 'Kapton' tape offer any advantage?)
- Anyways, you, the amp, (and us viewers) got there in the end.. well done 🙂
Thanks Gervais. I've got an Orange Matamp OIRST on the bench at the moment with a hum problem. Literally nothing I do changes it by so much as 1% so I'm completely stumped!
@@stuartukguitarampguy5830 Hey - Good luck with all that :-)
- have recently been looking into the concept of 'differential scope probes' - might they be of any use in such a situation?
- buut... they seem V. expensive:
ua-cam.com/video/OZDijMDHmtI/v-deo.html
- anyone know of any cheaper/DIY alternatives?
----------------
Please, need an advice. Is it ok if I connect one extra cap in paralel 47uf 500V in my Fender Hot Rod Deluxe?
1am and I've woke up and I'm wide awake. What could be better than a Stuart amp-whodunnit. The crackle might have got away if it wasn't for the pesky toothbrush 😆
I enjoyed this one a lot. Thank you kindly Stuart.
I'm pleased! All the best.
Well, wasn't that fun! If it was a PTP amp, it wouldn't have needed that repair. 😉
Thanks for the video. I only found one schematic and it didn't match the boards you were working on so I couldn't follow along that way too much. But I will say at one point, I was thinking volume pot, solder joints. I didn't see anything above that would leak on the board so I wonder what it could have been?
I guess we'll never know!
Hey there i have a Hot Rod De Ville 4x10 USA iv replaced the light bulb and it is still verry dim at first it was normal but now you can nearly see if its on any clue as to what that problem is thank you
Bit confused. Light bulb? DO you mean the red on/off indicator bulb?
I've a silicone straw for blowing warm moist breath onto boards / components/ I had an amp in which hum was bad and breath on nearly all tube sockets made it much worse. It was a 1965 Fender Deluxe Reverb and I wanted to preserve the original sockets. I removed them all, scrubbed them with dish soap and water, and soaked them overnight in isopropyl alcohol then blew them dry with heat. No more hum! My theory is that someone used a conductive product to "clean" the tube sockets.
Nice tip thanks. Often it's also just a build up of dirt/grease etc and a good clean gets rid of those unwanted conductive paths.
Thts what mine sounded like just before there was no sound at all . But what was the putrid burning smell tht was with it .I took the chassis out but cldnt see anything black or discolored. What might tht be sir . Thkx
Hmm tricky to say at a distance I'm afraid. Might need an amp tech for that one. Good luck.
Hi Stu, SNAP! I've got a Deluxe on the bench that has intermittent 'Drive' channel, took the main board out and reflowed every joint around V2 and I think it's fixed, but it's comes back intermittent again - f*ing Fenders!
It's a nightmare when that happens. I really hate it when a customer takes an amp away (usually having driven a fair distance) and contacts me next day saying "Err... it's back...". Aaaagggh!
@@stuartukguitarampguy5830 story of my life! Finally tracked down the fault to the relay K2, intermittent contacts, took about 3 blooming hours to trace :/
@@MreViewer Well done. I'll make a mental note of that one! I hate relays on amps tbh.
I had the similar cracking problem but not that loud, I shake the inverter tube effect the cracking sound so I just resoldering the tube socket and others soldering points around it and noise just gone.
Well done!
See the J hook on the cement resistor @ 3:50!
Great video!
That was a breath taking job :)
Great job Stuart.
Thanks David!
interesting 'shorting nodes to ground' technique - do you combine that with scoping other nodes?
Hi Gervais. I have a thing that I only get the scope out as a ;ast resort. 9% of faults can be found by good troibleshooting. But I certainly use it when I need to and get desperate!
@@stuartukguitarampguy5830 thx for reply - how aware of issues might one need to be in terms of low-impedance / shorts when test- shorting nodes to ground (esp. in HV valve circuitry?)
Hi Gervais. Sorry I didn;t really understand the question.
@@stuartukguitarampguy5830 Oh - think I meant like the difference between a 'low current' & 'high current' short - one diagnostic, the other perhaps fire-starting.. 🙄
@@gervaiscurrie6675 , I have a test-probe cable with pointy probes on both ends, for shorting signal to ground or jumpering around suspect parts ---- If I was a newbie I would make sure to have a fuse in line between those two probes, but I've been doing electronics for over 50 years so it isn't strictly necessary for me. Ask me again in 5 years if I've installed an in-line fuse yet, because of my hands getting shaky as my arthritis worsens.....😖
Great work you shared here thanks :)
Thanks Jacob
Those crackling/popping problems are always simple to fix, but complicated to find. Literally anything inside the amp can cause that problem so it turns into a wumpus hunt. I always start by carefully inspecting every solder joint- 90% of the time I can find one or more that are bad. It doesn't always fix the problem, but any bad joint will cause a problem anyway. Other than that, it's a tedious guess/test/check until the problem goes away.
Hi, yes agreed and that's what happened in this instance. Slow, methodical hunting.
I work fixing High End Audio for 30 years.
Most of the times I found resistors or tubes making cracking noise.
But capacitors , solder joins or PCB inclusive can make the same noise.
Best Regards.
It’s videos like this that really make me think twice about sitting directly in front of the 2x12 that’s hooked up to my JVM 😂 Really don’t fancy 100watts of that racket blasting in my face when something inevitably goes wrong… The joys of valve amp ownership!
Ha ha!
I wonder if something was spilt on that amp. Which would possibly explain the surface corrosion and also the weird powdery stuff between the back panel and chassis. And of course of any liquid had got on that valve board that could also explain the crackle. Either that or it’s been stored somewhere where water is leaking in.
Yes good point, I hadn;t considered that.
This was very interesting and helpful, thanks 🙏
Thanks I'm glad you enjoyed it.
@@stuartukguitarampguy5830 it was very informative
yes the indicator light
Hi Your comment is not not attached to your original comment which I cannot find, Please carefully explain the issue you are having and I'll se what I can do.
@@stuartukguitarampguy5830 yaaa i dont know what happen there but yes my indicator light do's dim flickering ???
@@moGear6253 If everything else is ok, then I suspect the actual connections to the back of the bulb. Try moving them around a bit to see if the lamp comes on solid.
thank you ill try looking at that socket it's dim all most noexzistance lol yup i all so noticed that sitting right beside the amp i got a lot of humming so i relocated my amp ???
@@moGear6253 Hi Mel If the guitar is anywhere near the amp you'll get a lot of hum. Just move the guitar away.
Hard work Young Stuart!! Would NEVER buy one of these damn amps! Always a bloody problem and extremely difficult to work on!! (I think they are actually made to be that way!!) 5*****
Glad you enjoyed it!
great video thx
Keeps it in his bedroom?
Good job Stuart! And guitarists, don't store your amps in a garage or a basement.
This amp suffered from more than damp storage, it obviously had something spilled in it. The rust and corrosion was readily apparent.
I have the same issue with a solid state amp, any advice?
Hi Kadeem Unfortuately crackling is one of those issues that can have quite a few causes.
@@stuartukguitarampguy5830 I realized, haha! Ok well thanks for the feedback. I'll leave it up to a professional. Cheers!
Just finished watching Hotrod repair vid just now - 'Repair Dentistry' :) - Looking fwd to future videos - Best now -
I'm selling those toothbrushes for £25 a pop if you're interested....
@@stuartukguitarampguy5830 - as my Dentist seemed to say to me as he was taking me under his Gas..
"Relax, Sir, : what Wife or Girlfriend would not come out delighted with your 'New Man Look' as you come back fitted with a full set of matched NOS Russian EL34 mouth-pins..."
*Shudder" 🙂
-Look fwd to more interesting vids -
Best,
Thank you!
Glad you enjoyed it Brandon.
Amazing that Fender continues to fleece it's customers with cheap ribbon cables,junk caps that will prematurely leak,and component placement that will burn up the board...at least they threw in some of Columbia's finest for the tech 🤪
It was good stuff too!!
Great video, thank you!
Thanks I'm glad you enjoyed it.
TAKE IT APART FIRST!! PLEASE 90% of crackle is bad joints you cant see when its together, plus those bad caps are effect not cause, so look UNDER. Take a few screws out PLEASE : > p
Nice to see you back Stuart .. I thought you might have been abducted by aliens in this mad and illogical world we live in . A bit like the illogicality of those faults you discovered and fixed. I think, I'd have thrown in the towel as I don't have your patience and determination. What a sad state the amp is in.. How long does it take to wipe a cloth over it ? They're nearly a £1,000 to buy new. Stay well and hope to see you soon..
Thanks Pete. More vids coming soon!
Amazing
Thanks Todd
If anyone is still struggling with this, make sure your phone or any other device isn’t on/right next to your amp, i used to keep my phone on it and that was the problem.
Great tip thanks.
Intermittent issues are time consuming to start with and to throw in a few leaky capacitors for good measure..our customers are lucky us old amplifier technicians enjoy the challenge cuz Sure isn't for the Money.
That's very true!
44:09 It's like something out of a horror movie
Just when you thought it was safe to go into the amp.....
You can lie to your dr. But you can't lie to your amp dr.
That was a bit of a nightmare :/ but I still think it could have been....that powder ;)
That's strange because after doing that sniff test I was completely out of it for 24 hours....
@@stuartukguitarampguy5830 😂😂😂😂
@@stuartukguitarampguy5830 :)
- yep -& those B@r$@rd flaky ribbon cable connections from the main PCB to the valve daughter board...
Fabulous design idea....
Maybe the garlic you had for lunch kicked off the noise? lol
That amp is ALWAYS going to have problems .
It is corroded .
Yep. It hasn't come back so far though.
Just looking at that level of neglect disgust me to no end.😬😬🤬🤬👿👿
This amp is on it's last legs.
What an awful amp.
Yes 'awful' ... I believe that was the word I shouted out a few times....
This will teach the owner not to play in the beach surf.
Fender and their cheap plate resistors
What kind of electrolytic filter caps do you usually use for replacement on these amps and the deluxe?
I LIke F&T caps as they are good quality. But I expect there are other makes that are as good too, I just don't know them all.
@@stuartukguitarampguy5830 right on, thanks man. Just got gifted a hot rod deluxe from a friend... Old roomie left it behind so I lucked out on a decent project. Noticed my caps are leaking and a lot of reviews say they're cheapo so I wanted to find a decent enough upgrade.