Pioneer SX-950: Should I Repair it?

[Duggo]

It’s a real quandary. On the one hand, it’s over 40 years old; on the other hand it was made before planned obsolescence was “invented.“

I should mention that item to which I refer is a stereo receiver. I suppose I just dated myself.

And yet on a another hand, Pioneer is supposed to be one of the best receivers.

Thoughts, comments, questions?

Duggo

 

[oc_in_fw]

I say yes

 

[john parker]

See one with updated power listed for $1500 on the internet. Better do it while replacement parts are still available.

 

[mrlandpirate]

I would very nice unit

 

[never-stop-learning]

Great vintage receiver.

What repairs are required?

 

[RayClem]

Whether you should purchase a new one or repair the old one depends on how you use it or might like to use it. Will it be reserved strictly for music playback, or might you be interested in using it for home theater with your TV, DVD player, Roku, Fire TV, or Chromecast device.

The Pioneer SX-950 dates back to the 1976-1978 model years. That means its audio inputs are limited to RCA analog jacks. The digital audio S/PDIF and Toslink standards date back to the early 80s, so your receiver predates the digital input standards that formed the basis of digital audio compact discs.

Due to the age of the receiver, many of the filter capacitors in the power supply and amplifier sections of the receiver may have either failed or are failing, especially any large electrolytic capacitors. Thus, the receiver may no longer be performing anywhere near its original specifications. Whether it can be repaired to its original state depends upon the skill of the repair technician as well as availability of parts.

Before making your decision, I would suggest you take a look at some of the current stereo or even A/V receivers. They will have a combination of RCA, S/PDIF coax digital, toslink optical digital and HDMI digital inputs and outputs. As long as the receiver has a high quality digital to analog converter using digital connections are preferred. Whether digital coax or digital optical is preferred is a matter if debate among audiophiles. A high quality DAC will have a minimum specification of 24 bits/192 kHz sampling rate, but premium DACs are available that process internally up to 32 bits/768k sampling rate. That is far above the original CD standard of 16 bit/44.1kHz sampling rate. Whether you can hear the difference between standard CD quality and higher resolution depends on the quality of your hearing and the quality of your playback equipment. High quality headphones are the preferred listening device for hi-rez music.

In recent years, music is being released in multi-channel formats and even in 3-D formats such as Dolby Atmos. If you intend to use the receiver strictly for a phono turntable or CD player, a stereo receiver will work just fine. While turntables are analog, CD players are digital and have both analog and digital outputs. Generally, the digital outputs will provide a cleaner signal than analog, just like digital television is an improvement on analog TV.

If you get interested in high-resolution streaming audio, many of the newer receivers can stream audio from Tidal, Deezer, Qobuz, Amazon Music HD, Spotify, Pandora, etc. using a built-in Internet connection. The higher quality streaming requires payment of a monthly fee.

Pioneer still makes some decent audio equipment, but things have changed in the past 40+ years. It no longer has the stellar reputation it once held. You might want to do some research before purchasing anything. Denon, Yamaha, Onkyo, Marantz, and Sony are a few names you might want to consider along with Pioneer. And this does not even mention the true "audiophile" brand names. Fortunately, the you should be able to learn what you need from the Internet.

 

[Stubblebum]

It is definitely worth repairing (depending, of course, on how extensive the needed repairs are). These types of classics are no longer made.

 

[never-stop-learning]

@Duggo - I should have added that, as one who listens to vinyl, single ended tube amps and big horn speakers, I would lean heavily toward fixing the SX-950.

 

[shavefan]

It depends. What's your skill level working on electronics?

Great receiver and can be a fun project if you're up to it.

 

[Duggo]

I don’ listen to it that much any more, because of an annoying problem that is coming from the speakers (HPM-100) At any rate, while I am listening to the radio, it will drop the sound.

I did have it repaired 10 or20 years ago, but at this late date, I can only presume that the problem continues, as I haven’t turned it on in ages. (because of that issue.)

So, is it true that if it sits around ((in the OFF position,) for say 20/30 years, does that put “wear and tear” on the receiver?

Apologies for not including the information previously in my initial post

This post was typed by hand, (hunt and peck style,) and sent from an iPhone 7 Plus

 

[shavefan]

After that long it wouldn't surprise me if some of the capacitors need replacing. A good multimeter with a schematic can tell you a lot. Get yourself a can of CRC QD contact cleaner, or even better DeOxit, and give it a good cleaning. Proceed from there.

 

[cleanshaved]

I would suggest getting a quote for fixing it.

My amp was having issues turning on and cutting out. I was trying to decide on a repair of replace myself.
The information I found on someone I was looking to use for repairing may be worth a read.
What tends to go wrong... Dirty controls/potentiometers and switches.... Also dry solder joints.

Repairs & Restoration - https://cowanaudioservices.co.nz/repairs-restoration/

Oh as a side note, it does not matter if your amp can't stream. I got a blue tooth receiver for my amp and can stream to it from my phone. Very cheap to buy.

 

[shavefan]

DAC's have analogue outputs, so no issue using the SX-950 "digitally". Just add something like a Topping D30 (about $100) and you are GTG.

 

[never-stop-learning]

So, is it true that if it sits around ((in the OFF position,) for say 20/30 years, does that put “wear and tear” on the receiver?

If the SX-950 has been sitting for 20 - 30 years without being turned on, do NOT turn it on.

After that long, it is much safer to bring it up to voltage on a VARIAC to reform the capacitors, lest one of them pops and gets capacitor gunk all over the inside of your receiver.

The sound dropping could be a lot of things. Both channels or one channel?

 

[CheapShvr]

Several have mentioned capacitors. Let me add a detail about why they are a problem after 20 or so years. They contain a liquid electrolyte that dries out in time. When that happens, they fail, especially under power. Other components can shift in value over time, too, even resistors. Functionally, it is as if someone has redesigned the circuit in your amplifier while you were sleeping and made it into one that does not really work. I saw an example of that about ten years ago. Our church burglar alarm was sending alerts to the police, but the building had not been entered. The police were ready to levy a hefty charge for responding to each extra alert. After talking with the alarm company, we were the proud owners of a new system. The old one was 25 years old and values on the circuit board had changed on their own over time. The new circuit board solved the problem.

 

[RayClem]

If the SX-950 has been sitting for 20 - 30 years without being turned on, do NOT turn it on.

After that long, it is much safer to bring it up to voltage on a VARIAC to reform the capacitors, lest one of them pops and gets capacitor gunk all over the inside of your receiver.

The sound dropping could be a lot of things. Both channels or one channel?

I am a ham radio operator and we have a saying concerning reactivation of vintage equipment. It is "let the smoke out". If this receiver has not been used in 20 years, I suggest turning it on din the springtime with the windows open.

 

[hydro-magic]

Repairing old electronics is a hobby of mine. If you have to pay for the repairs, they'll likely cost more than it's worth but if you have the tools and know-how to do it yourself, it can be a fun project. I found a schematic online - http://www.wwdsltd.com/files/PioneerSX-950Schematic.pdf From there it's just a matter of finding the problems which can take a bit of time. That's the main reason repairs cost so much - labor. You can likely repair it with some cheap parts assuming those parts are still available which can be a problem on older stuff.

First step would be to spray every switch contact and pot liberally with contact cleaner. After a long time sitting, those things will cause you untold grief so don't even bother turning it on until you've done that.

Dried out electrolytic capacitors can definitely be a problem and 45 or so years old is the point where you'd expect even good quality caps to start failing. I might just replace all the electrolytics before I even tried to turn it on.

All that being said, while your Pioneer is a nice piece of gear, it's still an old transistor based amp that won't perform better than a newer nice one. If I had a choice between paying a grand to fix the old one and buying a new one, I'd probably just go with the new one. You might be surprised what people will pay on the auction sites for stuff like this even knowing it's got problems so you can get some cash for it as is.

 

[shavefan]

@Duggo, you basically have three choices

(1) Repair it yourself. I have no idea what your electronic repair skill level is or how your electronic tool kit is presently outfitted but seeing as you had it repaired by someone else in the past gives me a clue that both may be on the low side of the scale (apologies if this is not the case). If you choose to repair it yourself you will need a good multimeter, soldering station, solder sucker, solder, tweezers, electronic pliers & screwdrivers, electronic cleaner & lubricant. All that adds up money wise. Then you will need to diagnose the receiver and buy the required components required for repair. Not sure what your time is worth, but you will have many hours in it when all is said and done. However, even if this is your first go at a repair like this you will gain a lot of knowledge in basic electronic repair. It's not that hard and can be very satisfying to learn and do something new.

(2) Have it repaired. If you know someone you trust to do the repair this may be a good option if you don't want to tackle it yourself. Make sure it's someone you trust though because the last thing you want is a hack job done on a fairly sought after vintage piece of stereo equipment. Repair prices vary so you'll have to get a quote(s).

(3) Sell it. These vintage receivers command some good money on the used market. You may be surprised. There are forums like Audiokarma you might consider joining to ask questions.

 

[never-stop-learning]

I am a ham radio operator and we have a saying concerning reactivation of vintage equipment. It is "let the smoke out". If this receiver has not been used in 20 years, I suggest turning it on din the springtime with the windows open.

That is certainly one way to do it.

Respect for your years as a ham radio operator. Hams have saved many lives and helped coordinate numerous rescue efforts over the years.

I've been heavily involved with vintage tube (and the occasional solid state) audio gear since ~1972.

From my experience, using a VARIAC or a "dim bulb tester" to slowly power up a long dormant component may not be as exciting as just "flipping the switch", but it is, in my opinion, the safer process.

YMMV

 

[hydro-magic]

^^^ This. It's a good idea to always use a current limiting light bulb and variac when powering up something for the first time in a long time. It alerts you to a short very quickly and can prevent serious damage.