Leestereo's Restoration/Upgrade Of A Sansui AU-7500

[Scott Muni]

Perfect timing, I'm looking for a AU 7500 for my next project.

 

[kwayde]

Pictures restored from Photobucket lockup.

When I restored my 7500 I found your post about the RIAA feedback being off so I corrected mine like you did yours. I haven't been using the phono since it's been serving lite duty in the garage system and hasn't been used at all during the cold months.

Just today I happened to look at hifiengine and found what Sansui had said about the amp which I attached below. I brought it in today and will be cleaning switch contacts and giving it a once over to be sure all is well. Then I'll hook up a turntable to give it a good listen.

Had a bit of a chuckle when I read the last sentence.

 

[Leestereo]

When I restored my 7500 I found your post about the RIAA feedback being off so I corrected mine like you did yours. I haven't been using the phono since it's been serving lite duty in the garage system and hasn't been used at all during the cold months....I brought it in today and will be cleaning switch contacts and giving it a once over to be sure all is well. Then I'll hook up a turntable to give it a good listen...

Note that if you replaced the stock transistors at TR601 &TR602 with KSA992 transistors, you may need to install small value (~47pF) Miller capacitors to prevent oscillations.

 

[theo01237]

@Leestereo ! Thank you first of all for this great thread. I just bought a Sansui AU-7500/TU-7500 matched set, which had trouble with producing sound. I did a thorough cleaning of the pots/switches with deoxit and all sound is back and seems balanced, and sounds pretty decent, for about an hour of running, after which the sounds starts to distort (due to old capacitor heating issues etc. I imagine).

I am planning on doing a recap/rebuild following your guide, but my question is regarding parts. Will buying the 'Ultimate' ebay kit of these units (AU-7500 specifically) be sufficient to follow your guide? I don't see any parts lists anywhere so wanted to get your opinion on buy the 'kit' vs buying each part by going through your guide and searching each part individually? Thank you!

 

[kwayde]

@Leestereo ! Thank you first of all for this great thread. I just bought a Sansui AU-7500/TU-7500 matched set, which had trouble with producing sound. I did a thorough cleaning of the pots/switches with deoxit and all sound is back and seems balanced, and sounds pretty decent, for about an hour of running, after which the sounds starts to distort (due to old capacitor heating issues etc. I imagine).

I am planning on doing a recap/rebuild following your guide, but my question is regarding parts. Will buying the 'Ultimate' ebay kit of these units (AU-7500 specifically) be sufficient to follow your guide? I don't see any parts lists anywhere so wanted to get your opinion on buy the 'kit' vs buying each part by going through your guide and searching each part individually? Thank you!

Marblehead kits are questionable. If you're going that route get the kit from peace.love.and.music.

He's reliable and an AK member.

 

[Leestereo]

@theo01237: Typically, the kits that I have seen available on eBAY do not follow my AK restoration/upgrade threads; you will probably have to compile a custom parts list (if you want assistance with this, send me a PM).

 

[theo01237]

@theo01237: Typically, the kits that I have seen available on eBAY do not follow my AK restoration/upgrade threads; you will probably have to compile a custom parts list (if you want assistance with this, send me a PM).

Ok thank you, will do! What I might do is just buy the recommended one from peace.love.and.music and figure out what is missing and order that separately. Will reach out if I get stuck. Was quite a dusty beast