Pioneer SA 7500 Repair and Restore

This turned out to be one of the nicest performing amps I've ever done. Even though this amp was only rated at 40 watts per channel, it easily reached 55 wats per channel after restoration. Great!

[@johnreel8944]

My first integrated amp was this SA-8500 and I really enjoy the crisp powerful sound. John

[@photography3807]

I just bought for a good price ($150.00 Canadian dollars - shipping include -or $112 USD) a Pioneer SA 7500, (MK1), 100% original and it still working great even if the capacitors are 40 years old. Very good sounding amplifier. Better than my modern Cambridge Audio Azur 351A.

[@mdimenke]

Great video! Very educational with the steps you go through analyzing the fault.

[@rainbowmat8204]

very good Restoration sir

[@resynthesizer4565]

Great video, and a beautiful piece of equipment.

[@afzaalkhan.m]

Excellent diagnostics and repair.

[@invmarthandan]

Excellent troubleshooting job

[@frankrinchiuso3380]

Man if i could do it all over again i wish i studied what you did! I have a Pioneer SA5500 II i would love to overhaul like that! Inspired me to get it from the garage and use it! Thanks for your insight and expertise! ( Regardless if I understood all of it lol)✌️

[@eclecticreader961]

Repairing electronics looks so fascinating when observing the work that is being done. I know if I attempted to do this myself, I would make a fool of myself, and the television would stay broken. I don't have the slightest clue on how to read the diagrams that came with the T.V. set.

[@vintagestereo]

great video, just scored a 7500 mkII

[@absoluteaudio0028]

a lot of hard work there

[@KolfMAKER]

Hi Tony, great video for learning. Thanks! I noticed that you measured for Ripple on the filter capacitors (multimeter set to AC mV). You measured 13 mV as acceptable. (1) Which values for this type of measurement would not be right? (2) What would you than do? Replace the filter capacitors?

[@g.fortin3228]

Love this.. plenty of juice for the level I want. great job and nice amp ! Can I ask what the driver transistor set was that you chose ?? Having trouble choosing a high enough gain model for my sx-737 restore. Same issue you had I think, replacements ( 3503's ) are a bit lower in gain than the 1451's were.

[@bretspangler8717]

correct me if I'm wrong, but a good take away from your video, is that when the power supply is at fault, a basic rebuild of that unit won't hurt and save time over testing every part, since this is such a well build machine, it just makes sense for the longevity

[@user-lh8rb5wx6q]

I am so grateful, for your sharing, generous personality, ways, object, and the sheer thought of all knowledge you just let me take part of for Free! You are humble, go through stuff with patience, and, to be honest, I can even find salvation in seing a video, it just proves some people are good people. Thank You So Much. Can I support you in anyway? Shame, I am in sweden and my inherited and beloved monster Pioneer. A-858 ( sold in europe, also sold as A-71 overseas tho), well, I shorted it and understand it is gross, I wanna restore it, somehow, with 1000 W marked power, and 2 x 27000 uF, 80 V. Capacitors, 24 kg. It should be put to life. Is there any US. amp that might be similar to this 1989 only, Reference Amp? Anyways, rhanks. Take care, keep up the great work Tony! //Patrik, Sweden

[@Gerrit-Max]

I got one since the early 90's and still going but the bass / trebble isn't working to well any more. I have just sourced a schematic so I think I'll be having a look at this soon as I want to keep this beast going. Back when I first bought it it wasn't working on one channel so replaced the main transistors (TO3 housing) on the big heatsink and it was up and running. I've had a few amps since then but nothing measures up to the Pioneer SA7500. BTW, my speakers are the Jamo J252, liik them up and if you get a chance try them on this amp.

[@JimSmith-qm9xh]

Hi There: These are great videos. thank you!!!! Starting a restoration of an SA 7500. Relative newbie to this work. I tested the output transistors as you did in the video. Unit unpowered and unplugged. Also made sure filter caps discharged. Unfortunately I got significant ohm readings across the combinations of pins that should be OL. Like 11k ohms. I feel confident that I had the correct pins selected, the right meter probe on the right pin and the combinations sorted properly. I am assuming this means that the output transistors need to be replaced. Am I right?

[@xraytonyb]

Try checking the output transistors out of circuit with the meter set in diode mode.

[@gertsy2000]

Hey good restoration and great video. Hope it's still going strong. Just got one of these and cleaned it up today. It's working fine but I guess it needs the caps done.

[@xraytonyb]

Thanks for the comment! It seems that most of the old Pioneer gear has issues with leaky caps. I also see a lot of issues with the small transistors in the preamp and tone amp. Best of luck with your restore! They are great amps.

[@gabrielr4270]

Hello friend very good video but to do that the amplifier must have all those devices used. a question. the amplifier is normally 40 watts per channel factory but what is the maximum power that gives me I guess not reach 100 watts ??? you think because I have one and wanted to know the maximum watts per channel

[@gabrielr4270]

and not if you know the SA-606 pioneer the is 40 watts per channel and has a brand vu meters and 100 watts peak per channel but it would be true that 40 watts to 100 watts can reach or pure lie ?

[@Synthematix]

depends what impedance the speakers are

[@ew7007]

Hey Tony, love the channel. Your vids have helped me so much and I thank you. I know this is an old thread but could you tell me what you replaced the 2SA726s with? I'm about to use KSA992s. Thanks

[@hilbert47]

For many years i'm the Lucky owner of de Pioneer SA 8100

[@TyTyTy87]

That was awesome! Thanks mate

[@MK-tj5bf]

Thanks for the video! Was wondering who was the winner? Pioneer, Kenwood, Sansui or Marantz ?

[@coreyfellows9420]

The film is from cigarette smoke . Seen it a thousand times

[@Z4NL]

Would have been nice know what replacement transistors you used. Those differential input pairs must be closely matched otherwise you wont be able to zero out the dc balance.

[@randomrepair1680]

I enjoyed this. thanks!

[@ianhames2465]

An interesting video as I am trying to understand how amplifiers work. Can you explain how you set the quiescent current in terms of how you connected probes and measured the current? Thank you.

[@adamwolfram6126]

Thank you for taking the time to make and share this video. Would you please share what transistors you used as replacements?

[@navpers4764]

Thank you very much ...awesome video !

[@g.fortin3228]

Could you have gone up one notch in the large filter caps size without worry for the switch handling the inrush ? any benefit in bumping it a little ??

[@filmic1]

I picked up a 7500 at a garage sale for next to nothing. I think it just needs deox in the pots because it drives my tx-7800 tuner (bulbs are burnt out), which also needs some deox.

[@emiliaiacono8186]

hi.. could you help me out with a SA 606 problem..? It only work one side... L side... What can I check or mesure to star to fix this..? please respond,,

[@johnreel8944]

Tony, What transistor part are you using that is in the TO-5 case? I have been using KSC3503DSTU and unsure if they are the best choice for me for heat dissipation for my SA-8500 restoration. Thank you, John Reel

[@TheSpacefanric]

That was great - I have a pioneer SA5300 that looks similar I got from the junkyard that I want to try repair. The wheat globe is blown (didn’t know it was called that) can you share that LED replacement ? Thanks anyway, was very informative as to where to start etc. cheers - Ric in Australia

[@kumuist]

Nice and explanatory video. Do you have schematic for technics sa 370S receiver?

[@gino3286]

Hi thank you so much for this extremely interesting and educational video. What about mains transformers ... what about their service life time ? Thanks again. Kind regards, gino

[@t1d100]

Excellent

[@segasonic9117]

I love my SA-7500 but it blew up on me in May :( The left speaker makes a nasty noise and the right is kind of low. From what I have read, I believe it is one or more of the transistors on the phono board. Really need to get it fixed.

[@darrenhartling]

by changing the capacitors, will that take away from the sound? These amps had a lot of speaker pushing power. I was under the understanding that, that is where they got the power, from big old capacitors.

[@tonyfleming3050]

Man - you've got some kit there! I have one of these amps that I bought new in the mid 70's, and it's still going (Lost an output transistor back then but I was driving 2 sets of speakers flat out at a party). I was pleased to find your video as I have a circuit but no service manual, and I have just noticed the crackling coming into the right channel, as described by some other owners. A few millivolts of fluctuation on the speaker output so maybe those transistors? I will see if I can find replacements. Any idea where I can source a service manual? Love your work, thanks.

[@nelisdrums9024]

You'll find a service manual on Hifiengine.com. You must register but there is nothing financial to it. www.hifiengine.com/manual_library/pioneer/sa-7500.shtml

[@amitanaudiophile]

Very nice , keep it up.

[@gabrielr4270]

Hello friend, the largest capacitors of 50 volts per 10000 uf you replaced them with equal ones of the same value or you used other values. and I imagine that all the others were exchanged for the same value?

[@keithputz918]

Hello. A family member gifted me an SA-7500 recently. It works, and quite well actually. But the left channel degrades over time. It eventually degrades to popping and sputtering sounds, barely making any sound at all. I've posted on Audio Karma asking for help. I have some tools and know how, as I am a tradesperson in the automotive industry, but not enough to really know where I should be going or looking. Would you be able to provide me with any tips? Wonderful video you have here. Thanks!

[@xraytonyb]

There is most likely one of the small transistors that is leaking after it warms up. Be careful operating this amp without repairing it. The leaky transistor could throw off the bias of another transistor in the amp and cause it and other components to fail.

[@rogerhelland7424]

Where do you get your schematics I have a sa-7700 pioneer and I can only find blurred one's that I can not even confirm capacitor size or positive side of the capacitor on the board or drawings since none of them are not marked

[@colebizwell5407]

Hey Roger, I'm working on an SA-7700 right now. I can send you the full service manual and answer any questions on it via E-mail if you like.

[@DoRC]

I saw you used muse caps. do you believe that different caps sound different? I know Elma silmic caps are supposed to be best but having the same electrical properties I question how they could sound different. the elmas do have silk and hemp in them (and are assembled by nude virgins)

[@Hagledesperado]

If you listen for a difference, you will hear a difference. That's just how human hearing works.

[@rudigerhoppe5708]

Nice video, had a SA9800 a long time ago and am getting very nostalgic. Should have kept it. I see you're using a double output signal generator. I only have one with one output (an Angel, btw, a kit like the frequency counter you reviewed). Can that be used just feeding both inputs in parallel? Thanks.

[@rudigerhoppe5708]

Not Angel, Ascel, damn autocorrect.

[@aman-mn5kc]

Nice Vid! Is that DC V on the speakers?

[@skipperrussell2025]

I need an on and off indicator bulb for this amp. Where can I get one? Mine works perfect other than that.

[@y2k6507]

How much would it cost to have my amplifier restored like that

[@mjadrnak]

Do you do this for a living and if so what would a restoration like this end up costing someone to get done?

[@wolfje407]

Can you help me with the pioneer sa-6300? There are 2 wires cut by me. Do you know what they do? Or not. Sorry for the short video. Greetings Sander.

[@wolfje407]

kzbin.info/www/bejne/fn2bdqqgfqyqrbs

[@zedius123]

Firstly, Thank you for making such an informative video, as others have said you are clearly very knowledgeable. Could you please offer some advice with regard to troubleshooting my issue? I have this amplifier but believe the relay to be faulty or perhaps another component is causing the relay to not kick in. Over the last few months it was intermittent, lately the relay refuses to kick in at all. It may be worth noting, at high volume a small amount of sound leaks through. I have ordered a new relay and your video has inspired me to re-cap the amplifier in its entirety as I have an interest in furthering my knowledge of electronics. Could you point me in the direction of where to find suitable replacement caps, transistors etc? (I cant find a high resolution schematic with values!) Thank you again!

[@zedius123]

I'm in the UK so I'm not a rival, don't worry! I will register on audio karma. I don't suppose you have a previous order list or anything you could email? Thank you!

[@xraytonyb]

No rivals on this channel, only new friends! If you give me an email address, I'll email you a copy of the service manual. It has a full list of the components as well as the schematics. Mouser and Digikey are great sources for parts, but the shipping would be pretty expensive to the UK. You most likely have similar stores over there. Thanks!

[@zedius123]

xraytonyb hi, my email is sir. nelson @gmail.com , regarding pioneer sa-7500, thank you sir!

[@zedius123]

Hmm, amplifier has turned on and relay kicked in fine today after a couple of weeks turned off. Any idea what to try checking?

[@xraytonyb]

My first guess would be either a faulty preamp or driver transistor or a bad capacitor. Those small transistors are known to fail. If you leave the unit on, I bet the relay will eventually click back out. You may be able to use some freeze spray to locate the bad transistor.

[@DavidBerquist334]

If the power transformer goes can it still be fixed

[@wokafloka7192]

can I come work for you for free so I can learn all this amaizing knowledge

[@DavidBerquist334]

I see many of them come in nice shape for e waste they work but they must be shredded

[@deutzmax612]

How much time do you need for one "normal" ampliefiere to restore?

[@friedmule5403]

12:06 I can't smell it but it looks just like the owner smoked cigars, it leaves an oily brownish substance. :-)

[@patrickbk5765]

Mi equipo parecido a este no tiene salida de audio pero si tiene el Voltaje 110V... que puedo hacer??

[@GigiMts]

Hi! I write from Itlay! I am the owner of this amplifier (SA-7500). I would like to know how a "boredom" can be solvedon these potentiometers/switches. During audio playback, at at their touch, they create noise and audio balance problems. Need only one cleaning or somrthing else? Thanks and congratulations for your videos!

[@MrSergiopen]

ho revisionato il mio 2 giorni fà ,l'ho aperto e soffiato ovunque e spruzzando detergente contatti a go gooo poi risoffiato ora va bene.

[@simonesimone8317]

I have the same amp, would you suggest me to recap?

[@peritolegista]

Tks

[@hqdefault]

I own that amp but the volume pot is now damaged :(

[@zedius123]

How do the wires connect to the PCB in these Pioneer amplifiers? I can't seem to get them off!

[@tonyfleming3050]

Long time ago but they are wire-wound. Ultra high quality connection as used in early computer mainframes.

[@carnicabij]

what transitors did you use?

[@stevewayne1480]

You seem quite knowledgeable and informative. However you REALLY need to mount your camera. The constant camera motion makes the video nearly unwatchable without inducing a headache. Thanks for the effort, but you're ruining your good work without a tripod.

[@coreyfellows9420]

I disagree ... A trilod would give ua a hamds on and up close look. We would never have any idea what he was working on or what he was pointing out, aside from him bringing the unit over to the camera time and time again .

[@benjamintmehaffey]

I like that he moves around and that we get to see different POV👍 no headaches here.

[@mateusznarka2712]

HI if somebody could help with my SA-8500II i got strange issue in one channel of power amp where on R10 got +46V and other side of this resistor got -47 and its burning...Have no idea.Checked all resistor ,transistor and have no idea...PLs HELP.Capasitors replaced on newones...

[@pedrorm8632]

Please dirección página online donde comprar you los transistores germanio,capacitores etc.

[@RobertKohut]

Nice!

[@wolfje407]

Can I send mij pioneer 8500ii to jou?? For a full rebuilding. I have some problems whit it. Gread video's jou make.

[@DavidBerquist334]

I saw one in recycling but couldn't take it it got shreaded

[@slashdotcom]

I have this amps, problem is sometimes you hear like a "tick" and all of a sudden you don't hear music anymore. Than again you hear a "tick" and the music come back. Plus a really weird thing, if i rise the volume to the maximum i can hear music coming from inside the amp. Any clue? I'm going to open it as soon i have a little bit of free time.

[@juancarlos22mx]

Es el relevador de protección que se encuentra en la salida de las bocinas, ahi hay un par de resistencias que necesitas devalorar para evitar que se proteja al subir alto el volumen.

[@wokafloka7192]

god your so smart

[@paulpaulzadeh6172]

camera move too fast , get dizzy in my head