KA-9100 - The SicMan Solution TA-100W

gort69

AK Subscriber
Subscriber
Bought a junker 9100 with a bad channel, fried TA-100. So I implemented the SicMan solution. (I think this is his deal, it was sent to me by another member)

It was simple to do and works perfectly, nice and cool and no difference that I can hear between channels. But the odd thing is that I installed the same setup on the side with a working original module and that side ran hotter'n hell. I measured the voltage between the two resistors (I assume this to be "bias" unless I'm misunderstanding) - on the side that works correctly it was 32mv. On the side that runs so hot it was was 160mv. I measured voltage at the zener, which was correct, tested the other diodes and replaced all 6 transistors and recapped the board, and still hot. I then reinstalled the TA-100 and it runs nice and cool.

std03-diagram.JPG .P7071075.JPG

Any ideas? Not really a big deal - this thing is really a beater and I won't do anything with it but monkey around...
 
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I have one playing fine with both channels done.
with rebuilt boards.
jm
 
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OMG. I have one with 2 dead TA100 cos I pulled its working TA100 to fix my other KA9100 with a dead TA100 and this also had a problem in the phono preamp if I recall. But a phono section not working in a modded KA9100 is still very very cool.
Also is there a similar hack for a KR9600. I have heard of the STK4048 amp being a drop in, but this is easier I think.
Thanks.
Srinath.
 
FYI:
You have to be careful with this mod. These devices supply alot of current so speaker shorts, wires etc
are a no no. I tried fusing each output channel with a 3 to 5 amp fuse.
John M
 
I prefer this(includes bias adjustment and bias transistor), see pics:

The diagram includes part number/values. Someone could probably make a circuit board but then 9100 parts would start to dissappear.
 

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The schematic in the previous post has been discussed here in the forums before for those that aren't aware. There's also some additional info that may prove useful. The relevant information begins at post #58
 
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...and there's always this....

P7261098.JPG

This was the bad channel in the junker....it worked, but distorted. No idea what he did beyond prying the cover off and soldering in a couple of transistors.
 
I prefer this(includes bias adjustment and bias transistor), see pics:

The diagram includes part number/values. Someone could probably make a circuit board but then 9100 parts would start to dissappear.
Hi, I tried building this circuit in a KA-8300 and I still have as yet to get it to work. The bias is a nightmare.
 
I'm still interested to know if anyone started manufacturing something to replace the TA-100W. I have a beautiful KA-8300 I would like to put into the line-up. I used to have another KA-8300 and it suffered the same fate.
 
well someone finally made one. I’ll be trying these real soon.

I'm still interested to know if anyone started manufacturing something to replace the TA-100W. I have a beautiful KA-8300 I would like to put into the line-up. I used to have another KA-8300 and it suffered the same fate.

916C74D3-1766-44C1-81BC-D549AD806060.jpeg D4F32206-E3DE-4CFB-A2F1-EBE203F8DDBC.jpeg
 

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I have a KR9600 to finish up and I'm going to make it a point to check them out.
:whip:
 
search TA-100W+ on Ebay
"NOT MINE"
and yes I believe it is.
been following this on another board on FB.
Only 1 left

He shows it on a KA8300 amp board and mounted on a KA9100 heat sink
 
I'd noticed. I sent him a PM inquiring whether he was going to build more, then I read he has an alternative in the works for the 9100/9150, so my guess would be he's going to. This does however pique interest for similar arrangement with the STD03s...
:thumbsup:

They have STD03's on them.
 
Probably to save time and hassle since they appear to hand assembled.

FYI - he also has a version available for the TA-200W/KR-9600. Pretty cool.
 
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