Sansui 3000A

[spaghetti]

Thanks Peter, nice suggestions there.

I am in the process of adding the modification to make the use of the receiver safer.

I read Sansui suggested to use 1000uF non polar caps, but I believe they will be hard to find at the shop.
I was wondering if the non polar specification was overkill and a regular polarized cap would fit the job.
All my other cap coupled amps use polarized caps, so my guess is it's safe... am I wrong?

 

[Watthour]

There are numerous threads addressing the 3000A and its modifications. Search those and many of your questions may be answered.

FWIW, the output caps need to be non-polarized to charge/discharge in both directions as the AC wave leaves the amps for the speakers.

 

[pacificwind]

Thank you. Meanwhile, cleaning is finished, here's a picture of my heavy beauty: https://www.flickr.com/photos/123886295@N08/16068698848/in/photostream/lightbox/

Tomorrow I will test it

a very nice collection of vintage electronics.like your taste-not all the gotta have's.

 

[elguapo511]

Can anyone lead me to the correct Modification paperwork? I keep finding documents and comments that people say are incorrect

 

[two.dogs]

https://www.hifiengine.com/manual_library/sansui/3000.shtml

 

[darkhosis]

From a garage sale today - original owner purchased in Japan (220VAC version, has a voltage switch inside set at 117VAC), sitting in the basement since the 90’s.. suggestions other than a good clean ?

 

[tom3]

Looks to be an unmodified, as built receiver. I'd hook it up with some throwaway speakers to test it out, let it run for a couple hours. And note the speaker connections are not exactly the standard configuration, take a good look there. Really a nice clean looking unit, good find for sure.

 

[kevzep]

Don't connect any speakers up to it without measuring the DC voltage on the speaker output.
It may be on the brink of a catastrophic failure, connecting a load up to it, may well send it over the cliff!!

If you measure less than 100mV, which for one of these would be a miracle unrestored and no output mod....then you could try some speakers on it.

 

[darkhosis]

Don't connect any speakers up to it without measuring the DC voltage on the speaker output.
It may be on the brink of a catastrophic failure, connecting a load up to it, may well send it over the cliff!!

If you measure less than 100mV, which for one of these would be a miracle unrestored and no output mod....then you could try some speakers on it.

I'll take your advice, Kev. the owner mentioned it "didn't work", which leads me to believe the caps are either done for or in need of reform. since this is from the era of Nixon and been sitting in a basement for the past 30 years - no rush to hear it work, yet.

 

[kevzep]

The caps wont reform, you'll need to recap it, or, surprisingly, the caps may be okay to power it up an see what the issue might be and to assess the unit....
I always encourage people to be cautious with these amps, they tend to be unstable at the best of times, so connecting speakers up to them is a crap shoot....

 

[darkhosis]

The 5000A I bought from the original owner bought it while serving over in Korea and his grandson used it thru highschool in the 00's. It didn't have the service update and was never worked on. The level adjust pot needed a serious cleaning and has now run solid for me for almost 2 years. There's no avoiding the eventual recap but you just never know..

 

[Watthour]

This might be a little informative, or at least entertaining:

http://audiokarma.org/forums/index.php?threads/here-sui-sui-sui.478057/

 

[darkhosis]

This might be a little informative, or at least entertaining:

http://audiokarma.org/forums/index.php?threads/here-sui-sui-sui.478057/

You're being modest, great thread - VERY informative. thanks!

 

[Watthour]

I believe most of this is still available:

8V Lamp, 0.25A, Fuse type, JKL GF6370 (560-GF670)
Fuse, 2A/250V, Fast, 0217002.HXP (576-0217002.HXP)
Resistor, 10Ω ½W, CCF6010R0FKE36 (71-CCF60-10-E3)
Resistor, 0.33 Ω ½W, ERX-1SJR33A (667-ERX-1SJR33A)
Resistor, 1Ω 3W RWM04101R00JR15E1 (72-RWM410-1-5)
Capacitor, 1,000 μF 35WV, UEP1V102MHD (647-UEP1V102MHD)

I threw in the lamp number since they are handy to have for these old units.

This is the modification, and how easily it fits above the chassis (without any mounting brackets):

And the schematic:

 

[darkhosis]

I will bookmark this thread on my notes, Ive got 2 other projects Im trying to finish 1st plus work & school on my plate. The lady I bought it from taught elementary for the military overseas. She sold me her complete set up: quadrophonic Akai R2R + 4 Pioneer speakers + this Sansui. It was a great experience, she was happy that I was interested in her old stuff. I am definitely motivated to get this up and running again.

 

[markuus3889]

Fig 4 Amended:



Mark K.

 

[markuus3889]

Factory Mod Parts Kit List:



The .33ohm 1/2Watt resistor is a misprint.

Mark K.

 

[Oscar66]

Just came across this post. There is a 3000a for sale in my area for $300. Looks very clean. Is that too steep or fair. I know the prices on many of these vintage amps have gone up quite a bit. Any info appreciated.

 

[tom3]

That would be absolute top price for a mint and working receiver and paper work and maybe a wood case. But that receiver is a performer when working right.

 

[Oscar66]

Thanks for the info Tom. I have an au-317 and tu-217 tuner. got them both for $300. Really nice looking units.