Pioneer SX1250 Restoration

[Guest]

Was lucky to find this unit locally in Melbourne few months back. Tested all functions and found everything working good.  Inspected the unit inside by removing the covers to see in what condition the components inside. I can see few leaky caps..power filter capacitors are leaking badly. Almost all light globes needs to be replaced. Got amazed  to see the huge 1.2 KW toroidal transformer and four 22000uf 80v power filter capacitors. Wooden cover came with all scratches. But it came really well after giving a light sanding and applying bee wax. 

 

Checked the DC offset and found to be low which is safe. Hooked them to my Tannoy Ardens. This is a unit which really surprised me with its wide ..deep sound stage and sweetness in sound. 

I'm slowly moving to valve and selling all my solid state units ... but decided to restore this unit to experience the full potential of the unit.

 

Anyway the restoration work started two weeks back.... Pictures attached here are before taking it for the full restoration... 

Will update more details, progress and pictures here...  any suggestions, advice from pioneer experts most welcome.

 

 

 

Edited August 29, 2019 by Guest

[Guest]

 

[Guest]

All covers,  power filter capacitors,  toroidal transformer,  circuit boards are taken out. The chaisis needs a good clean.

 

All metal parts in first photo will get copper plated.

 

 

 

Edited August 29, 2019 by Guest

[Guest]

The base of the big power filter capacitors is cut and open. Got them empty to use them as a cap for the new caps. They are aluminum and will get copper plated. 

 

Cleaned the capacitor covers nicely. It takes approx one hour plus to cut,  open,  empty and clean one capacitor can nicely. It needs further sanding using ultra fine paper and probably buffing before electroplating copper.

 

 

Edited August 30, 2019 by Guest

[lemarquis 591]

Interesting read here on this model. 160 W RMS! 

 

http://thevintagehifishack.com/197677-pioneer-sx-1250/

 

Good luck with the work and interested in the outcome. 

Edited August 30, 2019 by lemarquis

[niss_man 623]

What a nice rebuild. I've never seen anyone go to the trouble of electroplating the metal components before. Do you work in the electroplating business?

Should look fantastic with all that shiny copper everywhere. Some nichicon fine gold caps would look nice in there with the copper parts as well.

[Guest]

4 hours ago, lemarquis said:

Interesting read here on this model. 160 W RMS! 

 

http://thevintagehifishack.com/197677-pioneer-sx-1250/

 

Good luck with the work and interested in the outcome. 

 

Thanks. Yes, It believed to be one of the best unit ever made and preferred by many over other exotic models/brands. Both SX1980 & SX1250 share the same power transformer of 1.2 KW. I think SX 1980 was made to compete in the power race during those days where as SX1250 is built for music  .

 

4 hours ago, niss_man said:

What a nice rebuild. I've never seen anyone go to the trouble of electroplating the metal components before. Do you work in the electroplating business?

Should look fantastic with all that shiny copper everywhere. Some nichicon fine gold caps would look nice in there with the copper parts as well.

 Thanks  ... Same, I have never seen a restoration with electroplating metal parts. When I did restoration of my Marantz 2325 this was the only thing which I didn't do. This idea came into mind only after finishing restoring it, still that restoration drained my pocket.

 

No, I'm not working in the electroplating business   hehe. But a good friend of mine who is familiar with electroplating is happy to help me with it.

There are two reasons why I have gone for electroplating copper (especially tuner board covers) .

i) This unit deserves a better look together with its sweet sound.

ii) Electromagnetic shielding,  will be amazing if it helps to improve the sound anymore on this unit. ( here is an interesting read https://en.wikipedia.org/wiki/Electromagnetic_shielding )

     

Edited August 30, 2019 by Guest

[Guest]

Few of the copper plated metal parts are ready. Need to give them good clean. Considering some coating on top of this to prevent oxidation and it should maintain the same look. (There is some light reflections in the photos)

 

 

 

Edited August 31, 2019 by Guest

[Smoovie 32]

Looking foward to seeing the results!

[Guest]

 

[Guest]

[Guest]

Finally almost everything got finished on this SX1250. Got busy with work and this restoration job, so could'nt update the progress here for last few days .

Gone for Elna Silmic ii in 95% of the places to replace electrolytic caps. 

Power filter capacitors used are from Nippon Chemi-Con 22,000uf / 80v x 4. Will post photos here..

 

Next thing pending is the Speaker connection binding post upgrade on the unit and a huge round sticker on top of the toroidal transformer with Pioneer logo.

Edited November 16, 2019 by Guest

[Guest]

 

 

The wedge shapped big LEDs are Amber colour which I found that is giving yellowish colour tone like incandescent globes in room light.  But its a bit orangish colour in dark room.  

 

 

In room light

 

 

Without light in room.

 

[niss_man 623]

Absolutely stunning. 

[TOPSHELF 613]

Wow... I'd love to hear it.

[lemarquis 591]

Looks absolutely spectacular!

[Guest]

Here is a video of SX1250 in action. No dedicated DAC is used in this video as I have sold my Chord 2Qute and looking for something different to try.

 

 

Edited November 16, 2019 by Guest

[hiya 62]

Great job and thread. I particularly like the calibrated capacitor killing knife!

 

How can anyone not like a beastly receiver. 

[romekaff 95]

Love it!!! Best one I’ve seen! 

[Guest]

Thought of creating a video of this restoration. Couldn't cover all the process in the video. Was able to shoot some clips with the technician to make it different. Check it . .  

 

 

 

 

[Guest]

Update: 

This unit has gone into some trouble. Latter I inspected each board and found extremely poor soldering work and wrong voltages set inside the unit (biasing & voltage stablizer board) by Adrian at Analog Audio Solutions,  Cranbourne North. Also, it looks like wrong replacement transistors he put into the unit. Sourcing the replacement components and soldering work was given to Adrian and he did it in the worst way. It was a waste of time and money.

 

I'm a bit disappointed as it was my favorite solid state unit and wanted to keep it life long. Told him to take care of it like a baby. But it ended up in the worst. All the cosmetic work and cleaning was done by myself except electroplating. When trying to fix,  he made scratches on the copper plated areas also .  This is what happens when the unit goes to someone who don't understand the value of vintage gears and how much we love them.

 

Anyway I will get it all fixed properly as I love this unit like anything. Now the unit unit is with someone else to get it checked overall and fix it properly to bring it back to life.

 

Alert : Stay away from Analog Audio Solutions if you love your units.  He has gifted troubles to the units of a few people I know also.

Edited November 17, 2019 by Guest

[EDGEAUDIO 11]

Sorry to hear you have trouble finding a Tech that shows respect and care for these vintage rarities. I thought Melb was the vintage capital for caring Tech's. Thanks for the thread and the heads-up...

Finding a tech you can trust in SYD is impossible...to get my SX sorted!

[Guest]

22 hours ago, EDGEAUDIO said:

Sorry to hear you have trouble finding a Tech that shows respect and care for these vintage rarities. I thought Melb was the vintage capital for caring Tech's. Thanks for the thread and the heads-up...

Finding a tech you can trust in SYD is impossible...to get my SX sorted!

Melbourne has got some really good techs. But this person was very near to me and all the good techs whom I already know where too far in the other end of the city. 

 

This person setup his business few months back only, said he was working with another firm in Pakenham before and decided to start his own business. Sure, I was one of his first very few customers. Initially I gave him some small jobs and small units. There were some signs of poor knowledge about vintage units...the whole electronics itself. But its my bad, I failed to analyse him well from those incidents, lesson learned. Also I referred few of my friends also to this person and now most of their units are also in trouble, few of them got lucky.

 

Anyway, this unit is in safe hands now and I will get it done properly.

[Ulysses59 1]

No mention of the transformer being electroplated. How did you manage to do it?

What a beautiful  piece of legend you own. Congratulations. 

[Guest]

On 15/08/2020 at 2:32 AM, Ulysses59 said:

No mention of the transformer being electroplated. How did you manage to do it?

What a beautiful  piece of legend you own. Congratulations. 

Sorry for the late reply. The transformer and old capacitor cans are not electroplated, it is just copper finish paint.  All other metal parts in copper colour are copper plated. 

[Guest]

Received my SX1250 back after fixing the issue. While replacing the transistors in power stabilizer board the previous tech put low voltage wrong ones and it kept blowing.  

Anyway the second tech did an amazing job even though it was a long wait for me.  He has gone through all the work done by previous tech again, fixed bad soldering done by him and also cleaned the switches by dismantling them.  

 

Here is videos of the unit singing today...  ... Now its in better than brand new condition....

 

 

 

 

Edited January 3 by Guest

[hkc 387]

Absolutely stunning rebuild mate! Just beautiful 

[Guest]

On 04/01/2021 at 12:05 AM, hkc said:

Absolutely stunning rebuild mate! Just beautiful 

 

Thankyou 🙏

Now its a keeper... It sounds stunning and in perfect condition, will keep going for another 30 - 35 years..