I restored my mid 80s tape deck and pre-amp after watching several of your videos. Thanks for uploading your knowledge! The incandescent light bulbs with green condom has hardened and lost the green coloring so I replaced all with green 5mm LED which should last forever.
I don't understand how anyone can give you a thumbs down, you're showing how things are done for free basically, I'm enjoying them and giving you a thumbs up for every one, thanks.
I have a small size spring loaded solder pump with a teflon tip ($5). Sucks the solder right out of the holes in the blink of an eye. I have been using it for many years. I admire your perseverance, spending time on repairing a cheap piece of crap like that.
Great vids! I have dozens of old units and really like to figure out problems. Vids like this help me learn, thanks. It feels really good to fix a thing rather than throw it away. It's sad to me to see this good older stuff thrown away so I grab it when I see it and shelf it to mess with later. I have a lot to learn, that's for sure.
Hello, thank you very much. I solved the problem with volume motor. It had some corrosion, had the same problem. You can pull out the spacer, after taking of the end bell of the motor, so you don't destroy the brushes on the endbell of the motor. Also one motor pin was damaged, had to resolder. Was not easy to find your Video, maybee because of the wrong title. The Modelname ist Pioneer Stereo Amplifier A-X50, again thanx for the detailed video.
@@12voltvids I think it was good that in the title was the word "repair" Problems, I would add volume repair and bulbs, etc. So that is clear thats a repair video.
I wouldn't know why some folks hate Deoxit (aside from price), it's my go-to for cleaning contacts. The corrosive glue is called "Sonybond", it was used by quite a few manufacturers in the day with the exception of Sony. The Klein snips were originally used for cutting frame wires in telco shops and work just as well for component leads. The broken brackets can be super glued back on and the hardening can be sped up with a heat gun on low. Just my two cents, thanks for the entertainment as I'm never bored watching electronic equipment being repaired.
Night Stranger Deoxit is great. Yes it is expensive buy you get what you pay for. Sony bond funny because sony didn't use it. Yes I am aware of the original use for the lions snips as I work in the telecom industry. We use them now for fiber cutting as using anything else can cause the fiber to shatter several inches from your desired cut. Still used by frame personnel for cutting the ends off jumpers before removing them do they don't snag on other jumpers and damage them coming out. Had to do that yesterday when I was sent to a remote to run in some junpers.
I was given a 1988 pioneer 6 CD changer and when it would read a disk you could hear a loud pitch squeal coming from the laser I did a just the focus gain on laser and made it work like normal. This uses cartridge that was used in car CD changers.
way to inspector gadget this puzzle. nice work. dc ripple always a problem with the powerboard mega caps. automatic upgrade on this era of audio. as always great vid. this company always had beefy caps.
Craig deoxit is one of the best contact cleaners you can buy. It is quite expensive and that is what people don't like. They think it should be 1 1/10 the price.
@@12voltvids yes it's expensive but after my own experiences with it I don't care about the money.An audio crazed friend turned me on to it back in the 70's while I was doing sound for a southern rock band. I did a quick application to the amp sends in a three way tri amped setup. Before and after the system was 4db hotter!! NO B.S.!!! And this was just the house sends from the stage box to the amp rack twenty feet away and the hi mid lo sends from the electronic crossover to the stage sends.I had to back system gain down 4 db! To me that's proof enough.Four db in a tiny bottle still amazed me.
Great video as usual A small suggestion if it's broken and either mechanical or electronic or electrical do as my mum does out with the WD40 or its equivalent and shoot it into the works, she's cute with that stuff and sometimes it actually works Oh yes I'd be a deoxit fan but it is incredibly expensive in Australia
The holes on the back of the motor are for inserting small bush holder "pins" (like pieces of a paper clip/etc) when the end cover is installed. Same idea for holding back the brushes for say the field brushes on an automotive alternator.
Holding the brushes apart... yet another job for bent paper clip engineering. Straighten a small paper clip. Bend exactly in half. Bend last 5mm (1/4" ) or so of the ends at right angles. Insert in holes and use the paper clips natural springiness to hold brushes apart prior to re-assembly. Remove once assembled. "Trombone" for the win.
Andrew Hull That would do it. I didn't have a paper clip around so I just used a jeweler screwdriver on one side as it was a tight fit in the cap, and my dental pick for the other side. Done deal. There is more than one way to skin a cat.
Regarding the volume control motor, a few Q-tips and alcohol on the commutator & brushes cleanup with a follow up with the DeOxit would have done the same job; IMO.
Smashing repair :-D. The protection circuit would have confused me for a while too, and that motor drive was clever for the era, the volume display is unusual. Usually a motor drive means a remote control can be used, but i didn't see an i.r detector. Screw madness lol, the "Gotcha!" moment :-)
If I remember right, he said that the other components of the stack, the tuner and stuff, can remote control the amp. So, presumably some data line coming in the back from the tuner and stuff?
I don't see an IR sensor on any of the components, but there is a remote plug on each component , so they do talk to each other. Perhaps just for input selection or something, or there was an external remote receiver available as an option. Some companies did that.
I was never fond of wired together systems, they were special and you could not use different stack units, the psu was in one of the boxes and every box took power from it, impossible to use any unit on its own. I stuck to the normal phono/rca connector units, i liked choice. i like the old methods better.
A desoldering tool is great if you are a computer restorer because of those chips that have so many pins, but in your case there aren't so many things at once to desolder.
How often does all of not most of the componets on a multiple components system fail all at the same time ? I assume most people would unplug if now quit using it after the receiver or amplifier quit working. Thanks for all the great videos!
By design this one looks like it coms from the communication series, the one that came after their blue line series. This one I have never see before, I recal their integrated amps, the first being designated A instead of SA: A-5 A-6, A-8 A-9. those integrated all had fysical know to turn on instead of soft touch bottons... Still, this looks like an inbetween moment: we get Pioneer complexity even further expending, but with a much more inferior build quality, that would lead to were we are today. Looks seem to be quite okay though...
Anyone else can sit & watch this being snott and giving it a thumbs down , so I give it a thumbs up . Why sit there & watch a video they don't like for this long anyway ?
I have saved a lot of colored Christmas lights (incondescent. How can I use them in circuits, because every time I do, they blow. Thank you. Frank Reiser M.S. Frank Reiser Video/Audio Service
I usually know I've learned something if my vocabulary increases. The new word I got from this very informative video is "light condom", or green light condom. Try looking that up on google... thanks Dave. Oh and why was there a slight sigh in your voice when you said, "I've got two more to do." Sorry old boy!
I was waiting for someone to mention that. Good, that means you are listening. There are other less politically correct terms used to describe various electronic devices that have been commonly used in the service industry for years.
I tried a quick google search for specs but couldn't find an exact match. Going with + & - 42v rails, complementary symmetry emitter follower outputs driving 8 ohm load and reasonable circuit losses the arithmetic puts it at around 110 watts rms. I think 80 wpc rms clean would be a very good slightly conservative rating, but that's just me and i could be off a little. Those heat sinks looked a bit small for 80 watts. Not impossible, just a bit small.
12voltvids I have no other way to explain it but I hear this low-level buzzing noise every once in awhile in the background almost like it's coming from a clock on the hour?
at 43:49 you hear the alarm. Look at his wristwatch a little later (44:46), it reads exactly 7:00. not sure, but my guess he has an hourly alarm rigged up somewhere so he can monitor his repair time
I have another question if i record with a camera part of o movie. Saying what i have in common with the movie 10 seconds or the ball drop at newyears eve. Again maybe 15 seconds and post them if i give the sorce
Greetings. Please can you help me with the following ... I have a SONY amplifier and on the amplifier power card it uses ceramic capacitors of colors identical to the color resistors that create confusion; I identified them and was able to address them thanks to the screen printing on the plate and the service manual ... well, the question is if I can change those colored ceramic capacitors for "lentil" type capacitors ... of course, of the same capacitance and voltage if that exists? Thank you
I still have the old Iwatsu that needs the HV multiplier. The new one a Tek 2465 was donated by a viewer.It's a great unit that I have't even begun to use to the fullest. I just use it to look at analog wave forms. I have that cheap DSO as well, and it works for some things, but not so well for complex analog waveforms.
Those are in fact scissors made by Klein and cost less than $15. I'm not knocking your use of them, I own several pair and use them all the time. Great quality and made in the USA.
In Canada they are run more like 30, plus tax of course. In the trade they are called "snips" as opposed to scissors, because, well scissors are used in the office to cut paper. We don't say "order me new set of electricians scissors" we order a new pair of "snips" The larger "snips" used for sheet metal are referred to, in industry as "tin snips" Yes they are made in USA, Chicago to be exact.
Just wondering what peoples views on using WD40 as a contact cleaner are? It's what I have been using as I find contact cleaner to be more expensive here than WD40 and so far it's been working great.
Yes you can, and it will trigger a match at which point it will say eligible for revenue sharing and you just check the box "This is a cover of someone else's work" and it is done. They split the revenue.
About soldering tools: you probably are aware of those 40w soldering pumps. I will mention them anyway because i find them remarkably useful for the little money they cost (10 EUR or USD or so). Even desoldering an IC is perfectly doable with them. Review: ua-cam.com/video/5-EsOJNfDAc/v-deo.html
Ain't those motorized volume pots an attempt to keep those fussy audiophiles happy, because they believe the cheaper electronic alternative colours or distorts the sound of their vinyl records etc, on playback? ...or so i've heard. They even go as far as using switched fixed resistors for volume controls insted of pots in high end Hifi gear. Maybe not in this case given the age of this Amplifier...
I don't think electronic volumes even were a thing in the early '80s. Even electronic source selectors would still have been rather limited, with anything you could get being able to run on +/-8 V or so tops (e.g. 4066), and even then distortion specs would only have been so-so. (The parts capable of running at +/-15 V are also notorious for blowing up unless their inputs are well-protected.) Electronic volumes would have been a '90s thing, first appearing in TVs and car radios and the like, and it took until the late '90s and early 2000s for high-quality PGAs to finally appear (and those still aren't cheap). At that time, consumer home theater receivers would commonly use CMOS jobs running on +5V only with a single stage of attenuation, resulting in rather poor dynamic range (from very limited voltage swing + noisy amplifiers). When the spec says 95 dB of SNR, that doesn't sound too bad on paper, but in fact could mean an annoyingly hissy amplifier when full power equates to 110 dB SPL @ 1m and the noise floor does not actually reduce at lower volumes. Some even were 5 or 10 dB worse than that, totally hopeless! The current BOTL H/K model says 75 dB (higher-end ones say 100 dB at least), that sounds a bit scary...
in those days, there were no rotary encoders, any amp i ever saw from this period the motor was hacked to a regular pot, but usually with a manual knob on the front
Digital volume controls indeed distort the sound, and at low levels it goes up to .5% THD which makes a difference. Carbon track pots are OK, but there is a bit of engineering in making a good one that has an even thickness and consistency in the carbon, as well as the optimum feel and lowest wiper noise. Hence why Alps is still in business and not overtaken by the cheapest Chinese brand.
Hi my name is Chuck and I just subscribed to your videos I like your stuff always looking for someone to help me fix my Icom 211 let me know if you could be hired to do such get in contact with me I am desperately wanting the Shelf Queen to be in service again and locating somebody that can work on radios around here is darn near impossible
I restored my mid 80s tape deck and pre-amp after watching several of your videos.
Thanks for uploading your knowledge!
The incandescent light bulbs with green condom has hardened and lost the green coloring so I replaced all with green 5mm LED which should last forever.
I don't understand how anyone can give you a thumbs down, you're showing how things are done for free basically, I'm enjoying them and giving you a thumbs up for every one, thanks.
Got the same amplifier with the same problems and I did the same fix. Everything works fine, thank you very much!
I have a small size spring loaded solder pump with a teflon tip ($5). Sucks the solder right out of the holes in the blink of an eye. I have been using it for many years. I admire your perseverance, spending time on repairing a cheap piece of crap like that.
Fantastic. Great repair to watch and learn from - I have this amp and all of the tone lamps have failed. I will be ordering the replacements !
T
Plaq
P CV
Great vids! I have dozens of old units and really like to figure out problems. Vids like this help me learn, thanks. It feels really good to fix a thing rather than throw it away. It's sad to me to see this good older stuff thrown away so I grab it when I see it and shelf it to mess with later. I have a lot to learn, that's for sure.
GENIOUS REALLY. LOTS OF PATIENCE IS YOUR STRONG POINT.
Hello, thank you very much. I solved the problem with volume motor. It had some corrosion, had the same problem. You can pull out the spacer, after taking of the end bell of the motor, so you don't destroy the brushes on the endbell of the motor. Also one motor pin was damaged, had to resolder.
Was not easy to find your Video, maybee because of the wrong title. The Modelname ist Pioneer Stereo Amplifier A-X50, again thanx for the detailed video.
Changed title.
@@12voltvids I think it was good that in the title was the word "repair" Problems, I would add volume repair and bulbs, etc. So that is clear thats a repair video.
Good fault finding, you were very lucky with pc components not shorting out on the chassis metalwork whilst the unit was powered up !!!!
I wouldn't know why some folks hate Deoxit (aside from price), it's my go-to for cleaning contacts. The corrosive glue is called "Sonybond", it was used by quite a few manufacturers in the day with the exception of Sony. The Klein snips were originally used for cutting frame wires in telco shops and work just as well for component leads. The broken brackets can be super glued back on and the hardening can be sped up with a heat gun on low.
Just my two cents, thanks for the entertainment as I'm never bored watching electronic equipment being repaired.
Night Stranger
Deoxit is great. Yes it is expensive buy you get what you pay for.
Sony bond funny because sony didn't use it. Yes I am aware of the original use for the lions snips as I work in the telecom industry. We use them now for fiber cutting as using anything else can cause the fiber to shatter several inches from your desired cut. Still used by frame personnel for cutting the ends off jumpers before removing them do they don't snag on other jumpers and damage them coming out. Had to do that yesterday when I was sent to a remote to run in some junpers.
Solder wick has always served me well.
Very nice repair, really cool unit, and thank you for not using police grade bright blue LEDs in your conversion!
Blue led, yuck. I usually use incandescent bulbs to replace so they look authentic.
you're so good really enjoy watching you work ..Thank you
Interesting how the pot turned by the motor was not affected by contact problems but the knob for balance that is operated by a human was. :D
Excellent repair and interesting problems to solve! Thanks
I was given a 1988 pioneer 6 CD changer and when it would read a disk you could hear a loud pitch squeal coming from the laser I did a just the focus gain on laser and made it work like normal. This uses cartridge that was used in car CD changers.
way to inspector gadget this puzzle. nice work. dc ripple always a problem with the powerboard mega caps. automatic upgrade on this era of audio. as always great vid. this company always had beefy caps.
Nice repair, well done. Love these repair vids.
What a kool pioneer a50 mini power amp
Maybe you need to oil.the mooreture
Thumbs up for Pioneer mini amp.
Why would anyone not like deoxit?
I just spent $25 on some!👍
I love deoxit. Use it all the time. Always works.
Who could hate on Caig deoxit? That stuff is a gift from the Almighty to electrical contacts!
Craig deoxit is one of the best contact cleaners you can buy. It is quite expensive and that is what people don't like. They think it should be 1 1/10 the price.
@@12voltvids yes it's expensive but after my own experiences with it I don't care about the money.An audio crazed friend turned me on to it back in the 70's while I was doing sound for a southern rock band. I did a quick application to the amp sends in a three way tri amped setup. Before and after the system was 4db hotter!! NO B.S.!!! And this was just the house sends from the stage box to the amp rack twenty feet away and the hi mid lo sends from the electronic crossover to the stage sends.I had to back system gain down 4 db! To me that's proof enough.Four db in a tiny bottle still amazed me.
Great video as usual A small suggestion if it's broken and either mechanical or electronic or electrical do as my mum does out with the WD40 or its equivalent and shoot it into the works, she's cute with that stuff and sometimes it actually works
Oh yes I'd be a deoxit fan but it is incredibly expensive in Australia
nice work,repair must be patient.
Excellent job!
Sir, Have a joyous Father's Day.
This was some excellent troubleshooting! Your vids are great, just became a Patron.
Thanks.
Really good video Dave,,,, thanks man.
34:53 You're absolutely RIGHT ! It's my eyperience too that this helps a lot like on other things contact cleaner too.
The holes on the back of the motor are for inserting small bush holder "pins" (like pieces of a paper clip/etc) when the end cover is installed. Same idea for holding back the brushes for say the field brushes on an automotive alternator.
Thanx ,you do a awesome job every time
Holding the brushes apart... yet another job for bent paper clip engineering.
Straighten a small paper clip.
Bend exactly in half.
Bend last 5mm (1/4" ) or so of the ends at right angles.
Insert in holes and use the paper clips natural springiness to hold brushes apart prior to re-assembly.
Remove once assembled.
"Trombone" for the win.
Andrew Hull
That would do it. I didn't have a paper clip around so I just used a jeweler screwdriver on one side as it was a tight fit in the cap, and my dental pick for the other side. Done deal. There is more than one way to skin a cat.
love deoxit. Use it all the time and it works all the time .
Regarding the volume control motor, a few Q-tips and alcohol on the commutator & brushes cleanup with a follow up with the DeOxit would have done the same job; IMO.
Smashing repair :-D.
The protection circuit would have confused me for a while too, and that motor drive was clever for the era, the volume display is unusual.
Usually a motor drive means a remote control can be used, but i didn't see an i.r detector.
Screw madness lol, the "Gotcha!" moment :-)
If I remember right, he said that the other components of the stack, the tuner and stuff, can remote control the amp. So, presumably some data line coming in the back from the tuner and stuff?
True, I have the Pioneer DC-Z83 and the IR sensor is not on the main unit but on the tuner part.
White Tiger Gaming, yes that sounds very logical, i must admit that i didnt think that far.
I need some mental binoculars :-D
I don't see an IR sensor on any of the components, but there is a remote plug on each component , so they do talk to each other. Perhaps just for input selection or something, or there was an external remote receiver available as an option. Some companies did that.
I was never fond of wired together systems, they were special and you could not use different stack units, the psu was in one of the boxes and every box took power from it, impossible to use any unit on its own.
I stuck to the normal phono/rca connector units, i liked choice.
i like the old methods better.
A desoldering tool is great if you are a computer restorer because of those chips that have so many pins, but in your case there aren't so many things at once to desolder.
I agree about the desoldering. I use a manual sucker.
Yes I have one of those too, but for small jobs wick works fine.
How often does all of not most of the componets on a multiple components system fail all at the same time ? I assume most people would unplug if now quit using it after the receiver or amplifier quit working. Thanks for all the great videos!
Good job. Thanks for your time!
You don't want to see the tape deck. It was ugly.
Silly question...of course I do!
The 2 back to back transistors are in an SCR configuration. Company probably saving a few cents to avoid adding a new part# in the BOM.
perfect working ...
Light condom.. LOL.. all us techs call them that! sooo funny! Good job there!
You are at what you due
You can't rush these
things.They take time.
Nice trick fixing that motor
As long as the winding isn't burnt up they are usually fairly easy to fix the brushes.
Good to know in case I ever run into that problem in the future
Pre-digital volume potentiometers. Probably after this was on the market they said 'lets make this into 1 IC and save some money'.
By design this one looks like it coms from the communication series, the one that came after their blue line series. This one I have never see before, I recal their integrated amps, the first being designated A instead of SA: A-5 A-6, A-8 A-9. those integrated all had fysical know to turn on instead of soft touch bottons...
Still, this looks like an inbetween moment: we get Pioneer complexity even further expending, but with a much more inferior build quality, that would lead to were we are today. Looks seem to be quite okay though...
Anyone else can sit & watch this being snott and giving it a thumbs down , so I give it a thumbs up .
Why sit there & watch a video they don't like for this long anyway ?
Whoa now I wouldn't say rebuilt. Cleaned a little yes. Other wise great video.
The 'glue' - had struck again!
Now, if I had a dollar for every time I had to scrape the glue off. . .
Can you get a replacement online?
I have saved a lot of colored Christmas lights (incondescent. How can I use them in circuits, because every time I do, they blow.
Thank you.
Frank Reiser M.S.
Frank Reiser Video/Audio Service
I usually know I've learned something if my vocabulary increases. The new word I got from this very informative video is "light condom", or green light condom. Try looking that up on google...
thanks Dave.
Oh and why was there a slight sigh in your voice when you said, "I've got two more to do."
Sorry old boy!
I was waiting for someone to mention that. Good, that means you are listening. There are other less politically correct terms used to describe various electronic devices that have been commonly used in the service industry for years.
I missed the part about how many watts per channel. Great video, though!!
I tried a quick google search for specs but couldn't find an exact match. Going with + & - 42v rails, complementary symmetry emitter follower outputs driving 8 ohm load and reasonable circuit losses the arithmetic puts it at around 110 watts rms. I think 80 wpc rms clean would be a very good slightly conservative rating, but that's just me and i could be off a little. Those heat sinks looked a bit small for 80 watts. Not impossible, just a bit small.
That is a classic Pioneer receiver from the 1980s,
correct Sir?
what is that phasor noise I keep hearing in the background?
THEtechknight
I have no idea what you are talking about
12voltvids I have no other way to explain it but I hear this low-level buzzing noise every once in awhile in the background almost like it's coming from a clock on the hour?
at 43:49 you hear the alarm. Look at his wristwatch a little later (44:46), it reads exactly 7:00. not sure, but my guess he has an hourly alarm rigged up somewhere so he can monitor his repair time
How can you be reached to send a Tascam DA-60mkll in for repairs? Load dat tape problems it don’t have belts
I have another question if i record with a camera part of o movie. Saying what i have in common with the movie 10 seconds or the ball drop at newyears eve. Again maybe 15 seconds and post them if i give the sorce
Greetings. Please can you help me with the following ... I have a SONY amplifier and on the amplifier power card it uses ceramic capacitors of colors identical to the color resistors that create confusion; I identified them and was able to address them thanks to the screen printing on the plate and the service manual ... well, the question is if I can change those colored ceramic capacitors for "lentil" type capacitors ... of course, of the same capacitance and voltage if that exists? Thank you
Where did you get the kit to build the media player? I can't find one anywhere!
Did you ever fix your old scope or dump it due to the tripler unit fail..
And what scope is the new one..
Very good vid..
I still have the old Iwatsu that needs the HV multiplier.
The new one a Tek 2465 was donated by a viewer.It's a great unit that I have't even begun to use to the fullest. I just use it to look at analog wave forms.
I have that cheap DSO as well, and it works for some things, but not so well for complex analog waveforms.
Those are in fact scissors made by Klein and cost less than $15. I'm not knocking your use of them, I own several pair and use them all the time. Great quality and made in the USA.
In Canada they are run more like 30, plus tax of course.
In the trade they are called "snips" as opposed to scissors, because, well scissors are used in the office to cut paper.
We don't say "order me new set of electricians scissors" we order a new pair of "snips" The larger "snips" used for sheet metal are referred to, in industry as "tin snips"
Yes they are made in USA, Chicago to be exact.
Ahh, yes, forgot about the current Canadian to freedom unit exchange rate :)
Are those leds using the original 8v to light up?
Very good
For cutting leads, I gave a nail or something (for women) cutter from Revlon. Where do you find your schematics?
Frank
Just wondering what peoples views on using WD40 as a contact cleaner are? It's what I have been using as I find contact cleaner to be more expensive here than WD40 and so far it's been working great.
I wouldn't use WD40 to clean contacts. The do make a contact cleaner though. I use DeOxit and Nutrol to clean contacts.
good job
Love seeing the cat back! What are the 2 grooves on the outside of one of the snip blades for? Do they strip wire?
Yes they strip 19 - 24 ga telecom wire.
I was wondering about the snips!
Interesting. So this would be the competitor to Sony's MHC-2600 type bookshelf systems?? I love those sets,but.....lol
They are a pain in the ass to work on.
damn the a60 is built way better
For motors, why use Deoxit instead of motor oil between the rotor and stator?
Frank
Frank Reiser Video/Audio Service
There's a product called MaxPro Electric Lubricant that would be my go-to. If it's fixed, it's fixed.
I have a question about copyright you might know is it leagle to post cover bands playing multiple artists songs thanks
Yes you can, and it will trigger a match at which point it will say eligible for revenue sharing and you just check the box "This is a cover of someone else's work" and it is done. They split the revenue.
I have Samsung max-670 mini component no sound out put problem
There's a high pitch noise on your videos. Just got a frequency display kit. When your not talking the vary last bar on it is half way up. LOL
Never mind probably the CRT in your scope! ; ]
There is a CRT clock running over my bench, so likely the camera microphone is picking that up.
My brother destroyed a motherboard to a lenovo T-430 by putting to large screw in a place that required a small one.
I could tell they weren't normal scissors.
About soldering tools: you probably are aware of those 40w soldering pumps. I will mention them anyway because i find them remarkably useful for the little money they cost (10 EUR or USD or so). Even desoldering an IC is perfectly doable with them. Review:
ua-cam.com/video/5-EsOJNfDAc/v-deo.html
Ain't those motorized volume pots an attempt to keep those fussy audiophiles happy, because they believe the cheaper electronic alternative colours or distorts the sound of their vinyl records etc, on playback? ...or so i've heard. They even go as far as using switched fixed resistors for volume controls insted of pots in high end Hifi gear. Maybe not in this case given the age of this Amplifier...
I don't think electronic volumes even were a thing in the early '80s. Even electronic source selectors would still have been rather limited, with anything you could get being able to run on +/-8 V or so tops (e.g. 4066), and even then distortion specs would only have been so-so. (The parts capable of running at +/-15 V are also notorious for blowing up unless their inputs are well-protected.)
Electronic volumes would have been a '90s thing, first appearing in TVs and car radios and the like, and it took until the late '90s and early 2000s for high-quality PGAs to finally appear (and those still aren't cheap). At that time, consumer home theater receivers would commonly use CMOS jobs running on +5V only with a single stage of attenuation, resulting in rather poor dynamic range (from very limited voltage swing + noisy amplifiers). When the spec says 95 dB of SNR, that doesn't sound too bad on paper, but in fact could mean an annoyingly hissy amplifier when full power equates to 110 dB SPL @ 1m and the noise floor does not actually reduce at lower volumes. Some even were 5 or 10 dB worse than that, totally hopeless! The current BOTL H/K model says 75 dB (higher-end ones say 100 dB at least), that sounds a bit scary...
in those days, there were no rotary encoders, any amp i ever saw from this period the motor was hacked to a regular pot, but usually with a manual knob on the front
Digital volume controls indeed distort the sound, and at low levels it goes up to .5% THD which makes a difference. Carbon track pots are OK, but there is a bit of engineering in making a good one that has an even thickness and consistency in the carbon, as well as the optimum feel and lowest wiper noise. Hence why Alps is still in business and not overtaken by the cheapest Chinese brand.
Hi my name is Chuck and I just subscribed to your videos I like your stuff always looking for someone to help me fix my Icom 211 let me know if you could be hired to do such get in contact with me I am desperately wanting the Shelf Queen to be in service again and locating somebody that can work on radios around here is darn near impossible
Nice repair but honestly what a terrible piece of equipment.
Sometime you just get really mad repairing a pos that aint worth the money
I never get mad.
@@12voltvids I thought I was the only person up this time of day. Great videos man
LOL @ "Deoxit haters"!