Sansui PM-2020 Tube Amp

Zvezda and Dandy: To my knowledge, it has never been recapped. I figured a full recapping would be a must based on age. The writing on the back where the inputs are is in English.

Shadowdog: Thanks a lot. That definitely give me a little direction for getting this amp back in good shape. Also a nice reference to have comparing it to the Scott amps.
 
Thanks to all of you for your responses. I appreciate the feedback! My next question is should I attempt recapping myself on this unit or would it be better left to a vintage audio shop? If the latter, does anyone know a reputable shop in the Cincinnati, OH area? Thanks again!
 
If you are careful so you don't get a shock and you replace one cap at a time & testing right after each one so things don't get mixed up you should be able do it. Take lots of detailed pics in case.

You have to make sure PS caps are discharged before working on it each time.

The PS caps have a polarity so you have to be careful with that & the coupling caps do not. The PS can caps may be left in place for looks and unhooked & if there is room you may put new caps under the chassis.

The Selenium Rect. can usually be replaced with a UF4007 diode. You may leave the selenium rect. in place for looks & you may be able to use it to attach the new SS diode on one of its leads (as long as the other is unhooked) You can use heat shrink tubing to insulate connections. The new SS diode may change the voltage in the bias circuit so you may have to add a resistor to compensate.

The resistors could be checked at the same time as some may have drifted off. Just take the tubes out and they can be checked in circuit.

Pots & switches may be cleaned if needed + tube pins & sockets for sure.

You may know this, but just in case , don't run it with out a load even when testing (cheap speakers or 16 ohm/25W+ resistors) or you risk the Output Transformers.

Good luck!

Randy
 
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Nice amp!

If you haven't done this kind of thing before it is probably a good idea to bring it to a local tech, there are a whole lot of parts in there and it can be a pretty daunting task. It will cost a couple hundred but it will be finished and working in less than a year, which is probably a lot quicker than if you try it yourself.
 
I guess what I'm really getting at is... do you all think this amp worth putting the time and or money into a full restoration like has been mentioned in the last several posts? Or would the resto cost more than the amp is worth?
 
Yes. No. You have a rare piece there that deserves restoration. If you let us know where you live, someone near might be willing to help with the restore.
 
You will also learn a lot and be able to fix your own equipment! Wil save $ & you will have satisfaction of diy. Anyway it's definitely a quality unit well worth rebuilding!

If you post a bottom under chassis pic(s) that may help also.

Randy
 
Here are a few pics of the underside. Looks like quite a tangled mess and a lot of grey Suzuki caps. lol
 

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I think the the skinny grey with barbell ends are wirewound resistors and they should be great. Any Scott 299 first version isn't any easier. Could be worse like the Sansui 1000A.

Take your time and as I said one at a time and it will go fast. Just don't do too much at one time.

Jim McShane of tubes may be able to put together a nice kit of caps and needed resistors if you measure them. You can also go to the big vendors etc. Some advertised here.

Randy
 
I've called around to locate a reputable vintage hi-fi shop around cinci and I'm going to take it to one of them to see what kind of time and money they estimate, then go from there.
If its absurdly expensive and its going to be gone for a year, then Ill do the refurb/recap myself. Otherwise, I'm going to leave it with them... even though I wince a little when thinking of letting someone else do something I could be proud of completing on my own!
Thanks for all of your input and I'll let you know what I decide to do either way... hopefully, there will be a aesthetically and sonically pleasing piece to show soon!
 
Hey all, I found a local AK member (djef) who has taken on the resto/recap on my amp. Thanks again for all of your insight and ultimately, providing me with a person who is more knowledgeable than I! I'll give you a full update once I get it back and have a chance to listen.
 
I had one that was restored.

It is 20 by 20 and Sansui's first stereo integrated. Timelines suggest just that--and you are correct, 1958/59.

Its not avaliable on any Sansui site, history that is--there are also just a handful out there.

You have the 4th i've heard of. I will know by the pics if yours is one of the original 3 I've heard/ seen once I look back at your post.

It is a amazing sounding unit when restored...I have owed a lot of Sansui, this is one of the best sounding in my book when it comes to their tube units.

Rumor had it that these were produced for a limited market, as most were.
 
Thanks to fellow AK'er, DJef, my Sansui PM-2020 is back to life! Surely one of the best sounding amps I've ever heard and I havent even had a chance to listen to it through some efficient horns. I'll post some pictures ASAP. Thanks again for all of your knowledge and prompt responses!
 
Hi,
I have one here that suffered a completely botched recap. I desperately need pictures of a good underside beyond those posted earlier. A schematic would be icing on the cake, something I may need to bring this poor thing back to life. It currently works, but not properly and it suffered a short while just sitting there. It's not safe to run.

The person that did the recap left the original capacitors in place (thank god!), and jammed a bunch of axial capacitors to replace the bad ones. It looks like he pulled out some terminal strips and left connections in the air wrapped in tape. He even wrapped a power resistor up, which fell off it's leads when I touched it. Nice.

Any help would be deeply appreciated. The new owner wasn't aware how bad the work was and I'm trying to restore the unit and save him some money in the process.

Thanks for any help, Chris
 
I finished this amp a long while ago, and it works well. CE Manufacturing filter caps, it is pretty close to stock with modern coupling capacitors. The resistors were mostly good, replaced a couple out of tolerance.

I had to draw some parts of it out, and would still love a schematic for it.
 
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