Pioneer SX-1980 Transistor Modification

Looks like this one has been put up for auction on ebay. :tears:

About 6 hours ago. No bids yet.

A lurking (zero post) AK'er PM'd me about it.

It's back up again today on eBay (the auction pointed to this thread as background). BTW, did EW ever perform that 4 ohm load test and if so, what were the results?

Thanks,
Chris
 
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7,976 views.

We'll see how many more read this since they posted the url to the thread in the auction.
 
SX1980 Receiver

Hi EW,I just tried to post a thread but for some reason,it didn't take so I'll try again.I'm some what new to AK.I have a problem with my Pioneer SX1980.The tape 2 play right channel is not working.Left channel is fine.All other inputs work great with no problems.Any idea as to what could be the problem?
I sold this receiver last year on Ebay and got it back from UPS claims after being damaged in shipping.I'll comment on some other problems I had later on but those issues have been mostly resolved.One more thing is after being used for several hours,the transformer gets pretty hot to the touch.Is that a concern?Could the transformer need replacing?Thanks for any help.Al
 
Teac A6600 tape deck

Hi again EW,is there any one on AK that has knowledge of the Teac A6600 RTR tape deck?As you all know,this is a very rare deck.I have one that would play perfect but would not record.I found another one on Ebay that had a good PC board in it for record.I replaced the board.But my Tech in Warner Robins,Ga screwed up the play on it.
He obviously messed with the speed sensors.I have the record feature functioning again.He's tried to repair it for the last 3 months and still can't get it to play again.I took the extra A6600 to him to maybe use some parts from it to get the first one to play.Does any one know what it would take to get it to play again?Thanks for any help.Al
 
I am the site psychic, and I see you starting a new thread in the near future here for the 1980, and here concerning the Teac.

I also predict that you'll get an answer from me in your thread about the 1980, but not in the thread concerning the Teac, as my expertise does not extend to R-to-R's
 
Pioneer SX1980

Thanks EW for the response.I bought this receiver from the original owner a couple years ago in excellent condition.When I bought it back from UPS claims,UPS damaged it in shipping back to the UPS store in Warner Robins,Ga.The dial glass was broken so I replaced it with a better plexiglass.
I also got the tuner straightened out after removing a couple pieces of glass that got caught inside on the dial pointer.I realigned it but the dial is still a little stiff to turn.But works ok.The receiver is a 1979 model with the sensor gain switch on the back plate.The balance seemed a little off with a little more volume coming out of the left channel but I sprayed the controls with the Deoxit D-5 and the balance seems better.I have a couple extra caps for it just in case I need them later on.I also repaired a couple right side heat sink fins that got broke off at the bottom corner.I used JB weld to fix them and repainted them semi-gloss black.Over all,the receiver is still in great condition.But only after some work being done on it.Thanks for your help.Al
 
So where's that new thread?

FYI, the power transformer should never get hot. You have serious problems.

Do not answer here, please start a new thread.
 
Well, late to the party again...Glenn you have my admiration for what you have accomplished. Seconds to all those who helped in the manufacturing of the clamps and contributed $$. I want, know more than ever :yes:, want a SX-1980...GREAT THREAD and my thanks to everyone who contributed!!! The knowledge and ingenuity of the folks on this forum just amazes me...everyday!
 
I'm late to the party as well, so you're in good company.

As a newbie owner of a XS-1980, a recent eBay listing for three 2SD746A NPN transistors with a Buy It Now price of US$150 flagged my curiosity. I Googled '2SD746A 2SB706A substitute' and this is where I landed. Had no idea that these little critters were so unique.

EW, is the fix you describe in this thread still the way to go?
 
This thread should be a sticky, I am working on an SX-1980 as we speak and have blown outputs. I had not seen this thread until Markthefixer pointed me to it.
 
hello Forum...I too just found this thread..........fantastic reading! Good job EW!

Dare I say, that I am now hunting for 1980....................:smoke:


Great photos too..................
 
Models

So if Im getting any of this, it seems like the 1080 and also the 1980 and prolly the 980 and 1050 all have unobtaniums? I was worried about which to buy because they all look so swell. I bought as much for the looks as the power and sound. I play lower than reasonable levels and the 1080 I bought was a one owner, so I guess Ill just wonder how long it will last. Are the outputs prone to going out more than something else?
 
EW, I gotta' say that I just keep coming back to this excellent thread. Now that I have (finally!) a banged up sx1980, I may need this most awesome procedure.

EW.......what did you use as insulators? I am not familiar with 'Bergquist'-pads. What did you end up using for the final construct? How many units have you done this for? Were they all 'stable'?

Also ....the metal bracket mounts.......no drilling needed? Did you use the stock srcews/washers?

Thanks.
 
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Bergquist K10 Sil-Pad for TO-247 - Digikey #BER120-ND

Rebuilt two dead 1980's thus far. They run just fine.

Hard to call the new pieces 'brackets'. Just a chunk of steel with a couple of holes spaced so that they line up with the stock transistor mounting holes. More of a bastardized clamp than anything else.
 
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