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Pioneer 1050 - brand new to this

C

CutYourTeeth

New Member
Hello -

As the title states I am brand new to this website as well as brand new to the whole hifi or vintage stereo community. I had been reading as much as I could in the past couple weeks and went as far as attempting my own "repair" or cleaning without ever having dealt with electronics - Ive always been very intimidated by the idea.

I made two separate E-Bay purchases of a Pioneer SX-1050 and a Technics-1500 - I have been hoarding records for the past 8 years without a means to play them and figured it was finally time after acquiring a few albums Ive been yearning to hear for a couple years now. I went home that day and powered everything on just as the local vintage stereo repair man recommended. There were no issues... ...at first. After hooking up the turntable, I found that the right channel was extremely low in sound. After messing with the balance control, I pushed all the sound to the right channel, it was whisper quiet. Not to mention, the volume through the Phono input (1 and 2) was substantially lower than the sound coming out of the radio or the FM broadcast.

I tried swapping the audio outputs from the turntable into the other 2 Phono inputs as well as swapping the left and right inputs only to get the same result; always the right channel being extremely low in comparison as well as the overall volume being significantly lower through the turntable VS having the radio playing. So much so, that I would have to have the volume knob turned about 3/4 all the way up to have any reasonable volume out of the speakers. After messing with different setups, I am pretty confident in ruling out the the turntable as the culprit.

I went and downloaded the service manual and picked up some Deoxit D5, Faderlube (F5), as well as some of the Gold. I took off the top panel, bottom panel, and faceplate to gain access to the flat amplifier assembly and the potentiometer for the balance control, and gave it a good bath and applied the lubricant. While taking the receiver apart it was obvious that it had been taken apart previously. The shape of some of the screws, and the set nuts in the volume knob had been stripped pretty bad. While I had the faceplate off with the flat amplifier exposed, I also tried to gain access to the volume control as there was some static or a 'roughness' while adjusting the volume but found that it was not the basic potentiometer that the balance control was. This one, being encased by a square box looking thing... (please pardon my ignorance on anything having to do with electronics). I found others on the forum reference this same thing. On the back of the box there was a stock sticker that was depressed covering a small "hole" to give access to the back. I did a quick shot with the faderlube since I wasn't positive of what (if anything) would be exposed to benefit from it.

After putting everything back together, I can definitely tell a pretty significant difference in the sound quality, and the speakers are much louder than they were before while running through the Phono 1 input. BUT it still isn't even. The volume is still much lower than when its on the FM radio, and the right channel is still much lower than the left channel. From what I can tell, after the receiver starts warming up, I can start to tell more of a difference in the sound quality; being the sound slowly become degraded - leaking cap? This all may be in my head though... I am not positive.

I can absolutely see how people can get swallowed by this as all I want to do is learn more about it to the point I was starting to research the equipment to do the repair myself... but then reality hit... along with wiring diagrams haha. So now I am at the next step of what I should be doing because I am certainly at a loss as far as doing any diagnosing and repair myself, granted how friendly and willing to help this forum seems. But I also figured that if I am going to be opening up the case to replace whatever it is that needs replacing, that I might as well take care of the entire receiver once, and not have to worry about it for a while or if ever again... so I was thinking about doing a full recapping service. The guy who I originally spoke to quoted that it would be AT LEAST $1,000.00 to recap the receiver... Yes... you read that correctly... $1,000.00. That just didn't sit right with me. Granted I do live in the DC metro area where prices seem to be extreme in comparison but seriously... $1,000.00.

So I guess I am looking for opinions or idea's at what logical next step I should take. The receiver sounds good right now as it is, but knowing that it could sound better is what drives me crazy :-).

Thanks for reading this far and I am very excited to start learning more about this. And I apologize if there was too much or erroneous information in this post... I just thought I'd cover all the bases!

V/r
Ian
 
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CutYourTeeth said:
Hello -

As the title states I am brand new to this website as well as brand new to the whole hifi or vintage stereo community. I had been reading as much as I could in the past couple weeks and went as far as attempting my own "repair" or cleaning without ever having dealt with electronics - Ive always been very intimidated by the idea.

I made two separate E-Bay purchases of a Pioneer SX-1050 and a Technics-1500 - I have been hoarding records for the past 8 years without a means to play them and figured it was finally time after acquiring a few albums Ive been yearning to hear for a couple years now. I went home that day and powered everything on just as the local vintage stereo repair man recommended. There were no issues... ...at first. After hooking up the turntable, I found that the right channel was extremely low in sound. After messing with the balance control, I pushed all the sound to the right channel, it was whisper quiet. Not to mention, the volume through the Phono input (1 and 2) was substantially lower than the sound coming out of the radio or the FM broadcast.

I tried swapping the audio outputs from the turntable into the other 2 Phono inputs as well as swapping the left and right inputs only to get the same result; always the right channel being extremely low in comparison as well as the overall volume being significantly lower through the turntable VS having the radio playing. So much so, that I would have to have the volume knob turned about 3/4 all the way up to have any reasonable volume out of the speakers. After messing with different setups, I am pretty confident in ruling out the the turntable as the culprit.

I went and downloaded the service manual and picked up some Deoxit D5, Faderlube (F5), as well as some of the Gold. I took off the top panel, bottom panel, and faceplate to gain access to the flat amplifier assembly and the potentiometer for the balance control, and gave it a good bath and applied the lubricant. While taking the receiver apart it was obvious that it had been taken apart previously. The shape of some of the screws, and the set nuts in the volume knob had been stripped pretty bad. While I had the faceplate off with the flat amplifier exposed, I also tried to gain access to the volume control as there was some static or a 'roughness' while adjusting the volume but found that it was not the basic potentiometer that the balance control was. This one, being encased by a square box looking thing... (please pardon my ignorance on anything having to do with electronics). I found others on the forum reference this same thing. On the back of the box there was a stock sticker that was depressed covering a small "hole" to give access to the back. I did a quick shot with the faderlube since I wasn't positive of what (if anything) would be exposed to benefit from it.

After putting everything back together, I can definitely tell a pretty significant difference in the sound quality, and the speakers are much louder than they were before while running through the Phono 1 input. BUT it still isn't even. The volume is still much lower than when its on the FM radio, and the right channel is still much lower than the left channel. From what I can tell, after the receiver starts warming up, I can start to tell more of a difference in the sound quality; being the sound slowly become degraded - leaking cap? This all may be in my head though... I am not positive.

I can absolutely see how people can get swallowed by this as all I want to do is learn more about it to the point I was starting to research the equipment to do the repair myself... but then reality hit... along with wiring diagrams haha. So now I am at the next step of what I should be doing because I am certainly at a loss as far as doing any diagnosing and repair myself, granted how friendly and willing to help this forum seems. But I also figured that if I am going to be opening up the case to replace whatever it is that needs replacing, that I might as well take care of the entire receiver once, and not have to worry about it for a while or if ever again... so I was thinking about doing a full recapping service. The guy who I originally spoke to quoted that it would be AT LEAST $1,000.00 to recap the receiver... Yes... you read that correctly... $1,000.00. That just didn't sit right with me. Granted I do live in the DC metro area where prices seem to be extreme in comparison but seriously... $1,000.00.

So I guess I am looking for opinions or idea's at what logical next step I should take. The receiver sounds good right now as it is, but knowing that it could sound better is what drives me crazy :).

Thanks for reading this far and I am very excited to start learning more about this. And I apologize if there was too much or erroneous information in this post... I just thought I'd cover all the bases!

V/r
Ian
Click to expand...
Wanted to wish you good luck and care on your new endeavor, You remind me of me did the same thing except bought a couple really dirty ones first and smaller like the sx-780 used soap and water first taking care of not spraying front boards used masking tape, Blew off with air then went at it with DeOxit before realizing the spray is adjustable check top... Can empties fast on high. give it 24 hours or more to dry! recapping a 1050 is difficult with no experience and the right tools... Best advise leave Amp board for last if all is working build a DBT use 100 watt bulb too protect your new parts. read all the posts on recapping, repairs here then decide. I didn't use soap and water on my 1050 just DeOxit and air. the problem with the phone issue like mine is in the function switch "Usually bad and burnt contacts" just try and push on the phono button and see if the right channel sound changes. I have that issue on both Pioneer receivers 980 which I really like on the Aux and Phono lot of current and connections in those switches can remove white holders and take cover off to clean and lube they can also come apart so I was afraid of that bad eyes and back. Remember DBT very easy too make current runs thru bulb if there's a short the fuses save nothing.. I was told they keep from burning down the house LOL. I have been repairing mine now since October last year with at least 7 orders from mouser, more Transistors then I can count. "Just one mistake and your nice working unit will be a dead unit" I'm over 800$ in the hole now and it still doesn't work now just a Hobby. I found a great book on Basic electronics from the early 90's. did refresh some old memories like Ohms law and what all the parts do you will have to understand this. Maybe with some luck some tech from the site will offer recap cheaper take them up on it. great sounding amp when they work. I only wish I went for a SX-1080 newer and better built. If you go for DYI buy good soldering station not junk and good de-soldering tool or sucker.don't want too damage unit.
 
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Rebuilding a SX-1050 can be quite a task. Go to the DIY forum here and right at the top is a posting by echowars on repairing. Read it and go from there.
 
Ian,

Your enthusiasm is commendable. I had a feeling that there was at least one sensible and rational human being in the DC area. You must be the one.

As you have probably already noticed there is an abundance of advice, information, and guidance available here. As with anything found on the internet, proceed with caution and measure the advice given carefully. Some of it will be correct, appropriate, and reasonable. Some of it will be utterly useless. Qualify and verify.everything. MOST of us will have done that before posting, but everyone here is human and thus prone to errors.

One beauty of the SX-1050 is that there is ample real estate to perform maintenance and repair. Furthermore, there are so many examples in existence and some VERY good and expert resources with experience in that specific unit that you should be able to do almost anything with so long as you have the will and rudimentary skills and equipment.

In short, hang in there, and be prepared to read and post a lot of information. You'll at least get $1,000.00 worth of education and still have a remarkable piece of audio gear at the conclusion.

To expedite the process a bit you can help with some replies. Do you have a 30-40W solder iron available? Do you have a multimeter? Do you have a secure work area to disassemble the unit and allow it to remain for several days?
 
Thank you all for the feedback. As far as as supplies I have... well... I have NO supplies or hardware that would allow me to perform any electrical work effectively. I would in turn have to find out what I needed and I would have to purchase these things to do anything as far as fixes are concerned :) I DO however have a secure work area to dismantle the unit and leave for days without interruption.

I have since managed to pick up an RG-1 and an SG-9500... I'm sure I'll be making a separate post asking for additional information on the appropriate way to hook these things up or how to wire the RCA cables... Thanks again for all the information. Its truly, truly appreciated.
 
Also I forgot to mention/update - I read in a few other threads with people having similar issues. One solution or to help diagnose, was to simply push in whichever Phono button the unit was hooked up to in further and see if that changed the sound at all. I can say, that after doing this, there was also a difference in sound. It was much louder when depressed fully. Since then, the overall volume of the receiver has been louder but there is still the same issues I was dealing with initially, but maybe not as severe in the lack of sound.
 
CutYourTeeth said:
Also I forgot to mention/update - I read in a few other threads with people having similar issues. One solution or to help diagnose, was to simply push in whichever Phono button the unit was hooked up to in further and see if that changed the sound at all. I can say, that after doing this, there was also a difference in sound. It was much louder when depressed fully. Since then, the overall volume of the receiver has been louder but there is still the same issues I was dealing with initially, but maybe not as severe in the lack of sound.
Click to expand...
Their selling really high on eBay right now almost 900$ I like my 980 better, Cleaned up nice and works like a charm maybe newer amp design? Don't get me wrong I love my 1050 but for the inexperienced it's very easy to screw up a nice working unit wanting to make it better. Mine was dumped on eBay shipped poorly and now it's my problem. The hotter it got the worse it sounded the opposite with my 980... I'm glad pushing on switch helped you out keep doing it might clear up after time. I see daily posts were someone made an error with a 1050 or 1250 and it's back to step one again specifically the amp board. These old boards don't like heat so you got one shot at getting it right or you'll have a mucked up board and a dead unit, good luck finding someone who will even work on it after you mess it up...
 
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Actually the 1050 has quite a bit of room to work in. Pop open a '90s-'00s Yamaha or Denon HTA and see how congested those are, then try digging in to access the smoked outputs and emitter resistors. You'll appreciate the real estate inside a 1050.
 
Wanting to do a 1050 right now myself. Just to save me time of looking around, was hoping someone has a link to the most recent BOM list
 
Maybe a noob question, but I haven't dug into my 1050 yet, but reading some threads I see power supply A and a power supply B boards, are these different models or are they separate boards in the same unit?
 
what do you mean A,B?, revisions of the pcb assembly or the two different parts of the supply, rectifier and regulator boards? I only know of revisions on the surge suppressor pcb that I have never seen documented. I have a AWX-108, most seem to use the old one AWX-098. So I guess my PS are the latest/last production, if my surge is the later one. I will check since I have it on the bench.
AWX-108-0 BWF (Surge)
AWR-104-0 BWR (Rectifier)
AWR-103A BWF (Regulator)
I guess the "BWF" is the mfg date code

Their selling really high on eBay right now almost 900$ I would dump it and get a 980 or 1080
I have to disagree with this advise.

I love my 980 cleaned up nice and works like a charm better design I think, my 1050 is a nightmare fix one thing and something else shorts out... It was screwing up and then dumped on eBay. now it's my problem.
I am well aware of the struggles that you are having fixing your unit. It reflects more on your abilities and troubleshooting skills than it does on the design itself.
It is your opinion that a 980 is a better design, explain why? is it looks or actual circuitry?
 
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There are two "power supplies" in the 1050, one A and one B. B (AWR-104) is located on the bottom of the unit and the A (AWR-103) is located in front of the power amp on the topside of the unit.PS-B.jpg PS -A.jpg
 
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