• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Technics SU-8099 Rebuild/Restore

perokl

perokl

New Member
Hello all,
I'm here now, and im sure the vast knowledge held on this site, is going to help me.
After successful rebuilding my SU 8077 and SU 8088 now ist time to do a rebuild on my old dusty SU 8099.

IMG_20181009_173137.jpg

I made a list for the Capacitors (some are leaky) to replace:

8099CAP_01.jpg

I'm also planning to replace the trimmers for Bias, all Relays and take out and clean all switches .
On the SU8077 I also changed the double transistors 2SA798/SC2291 with SA992/SC1845 and on the SU8088 the SA995/SC2291 with the same SA992/SC1845 as recommended here:
http://audiokarma.org/forums/index.php?threads/technics-su-8077-rebuild.756525/page-3#post-10357951

On the SU8099 main amp. board I found the SC 2291 and SC 1583 double transistors,

IMG_20181013_214523.jpg IMG_20181013_214503.jpg
Should I also change these whit the SC1845?

I also found double transistors SA995/SC2291on the MC-EQ preamp board

IMG_20181013_214352.jpg IMG_20181013_214411.jpg

should I change these too? Whit SA992/SC1845 or something else, or should I keep the old ones?

Does anyone have any suggestions on what should be done else,which parts should be also swapped out,

that the amp last for another 40 years?
 
Last edited:
Register to hide this ad
You want to go really easy with this amp. I tried to restore one but a few things went wrong along the way and as the amp is so complex I ended up giving it away.

This amp has complex circuits, and several FETs. I wouldnt change anything unless you have an issue. Ie: dont change any of the double transistors unless you have unstable DC offset or audio crackling.

Is it currently working? Do you have the service manual for it?
 
I like the 2sa970/c2240, just that I have lot. The A992/C1845 are perfect also. You'll need to bond the two transistors together and make sure you match them in sets.
 
Yes, I have downloaded the service manuals and the shematic.
The amp is working prfect, I just wanted to get the amp restored, it has leaky caps and I thought, if it is open and disassembled,
IMG_20181013_181150.jpg
I could do something else on it.
 
FYI, a little piece of heatshrink tubing works great to "bond" transistors together. And if you want to go the extra mile, a tiny dab of thermal compound in between them before heatshrinking. ;)
 
Yes, I always match them in sets and heatshrinking with a drop of thermal compound. I think I'll replace them, I read somewhere that they often break down.
I already ordered the capacitors and the three big relays, but i can not find a substitute for the small HB2E DC24V reley.
Does anyone know of a source for this reley?
 
You must log in or register to reply here.
Back
Top Bottom