Yea... I have the gerber data to make those boards if you don't have it. Lots of complicated transistor matching to do for that amp and the fets are also hard to get. PCB's would be fairly costly per set... Modding an existing amp would be far easier... Typically 1200.00 to 1800.00 to buy and oh that nice metal work Krell did for those amps that would cost as much as a complete used amp to duplicate. Making a KSA 160 out of a KSA-80 is very easy and KSA-80's are more common.
Mark
Mark
KSA
There are a pair of KSA-160s on Agon now. $3900 (ouch)
I have a gutted KSA-300 chassis that I am planning to put a pair of KSA-50 amps into, or a ICEPower module with the KSA-50 for biamping. That chassis went thru hell and back when I got it (amp literally burst into flames with previous owner) - sandblasted it and anodized it black a year ago...
There are a pair of KSA-160s on Agon now. $3900 (ouch)
I have a gutted KSA-300 chassis that I am planning to put a pair of KSA-50 amps into, or a ICEPower module with the KSA-50 for biamping. That chassis went thru hell and back when I got it (amp literally burst into flames with previous owner) - sandblasted it and anodized it black a year ago...
Attachments
I was fortunate to have a nice KSA 80 fall into my lap a few years ago. It sat neglected for a while, after it started popping and thumping loudly in one channel. After letting it lay idle for a year or more, I brought it into the factory with me one day, and had one of my techs look it over (I am too lazy to get in there myself…). When he opened it up, a bunch of micas came falling out like discarded termite wings. All the plastic fasteners holding the driver and bias transistors to the common heat sink had crumbled, and some of the parts were leaking to the blue metal strip that serves as a heat sink.
We replaced the errant hardware and insulators, and the noise was gone. I haven't reset the bias- the amp is running a little cool at the moment, and one channel is slightly cooler than the other. But it still sounds excellent!
I have a pair of driver boards partially built up to replace these if they ever go South… but they will probably end up going into a new amplifier one day.
We replaced the errant hardware and insulators, and the noise was gone. I haven't reset the bias- the amp is running a little cool at the moment, and one channel is slightly cooler than the other. But it still sounds excellent!
I have a pair of driver boards partially built up to replace these if they ever go South… but they will probably end up going into a new amplifier one day.
KSA50 Pinkmouse's board, 3 pair 2SA1943/2SC5200, Biased to 650mv across .68ohm emitter resistors, 36VDC rails...so a biased up a little more than the KSA50,
Are the Jim audio KSA100 boards on fleabay good ...?
The IVa has the ribbon tweeters that really make a difference, I think the IV had a quasi ribbon tweets...
Why bother buying a KSA-80, lets just clone it! The output devices and raw components probably are much better now than on the original KSA-80
Lead ..... follow ...
Yea... I have the gerber data to make those boards if you don't have it. Lots of complicated transistor matching to do for that amp and the fets are also hard to get. PCB's would be fairly costly per set... Modding an existing amp would be far easier... Typically 1200.00 to 1800.00 to buy and oh that nice metal work Krell did for those amps that would cost as much as a complete used amp to duplicate. Making a KSA 160 out of a KSA-80 is very easy and KSA-80's are more common.
Mark
True , then you still have to go thru and refurbish the amp... added cost ..
For what it's worth Agostino did tell me he will service Krell amplifiers if need be , just contact him at his new gig ..
Regards,
Are the Jim audio KSA100 boards on fleabay good ...?
I have never dealt with Jim Audio's KSA100 Boards, haven't heard anything bad....
True , then you still have to go thru and refurbish the amp... added cost ..
Price to refurb a unit would be quite costly...
For what it's worth Agostino did tell me he will service Krell amplifiers if need be , just contact him at his new gig ..
Not to nit pick, but its D'Augustino, not Augustino, correct?
Are the Jim audio KSA100 boards on fleabay good ...?
FWIW, I have a pair of jims KSA-100 boards. Very nice boards, highest of quality. If I remember correctly there is an error on the silkscreen somewhere, a diode or cap printed reversed or something. They are a little larger than an original board, but otherwise the layout of the pcb is almost a carbon copy of the original.
I have not build anything with the boards and have not examined them very closely, so I don't know if there are other problems with the boards.
If you like I can send you the BOM and schematics I received from jim when I purchased the boards.
Regards
correct?
September two years ago it was Marchino.
After ~20 years (that's almost half my life) i still own a KSA-50, and it's still playing every day.
Back when i bought it , i auditioned it together with a Treshold amplifier, i'm afraid i forgot what type it was.
At the time i preferred the Krell because the sound had a little more 'bite' .
Which one was better ? So many fools, so many opinions
In my enthousiasm about another (diy) amplifier i think i may have trashed the image of the ksa-50,
apart from loosing some braincells i like to think i've become a bit better at using the ones that still remain.
I built a Klone as well that never got past the experimental state, but it sounded fine and similar to the original.
IF i ever were to build a Klone again, i would be tempted to go with high(ish) rails
(i think Mark said previously that the Klone really started to sing at 42V rails)
and use enough outputs to keep dissipation per device within reasonable limits.
Does it make sense to own or build such an amplifier ?
Making sense is what has given us mp3, crappy $30,- dvd-players , etc.
To this date i'm still happy that Dan D'Agostino had the heart to design and build the KSA-50
Best regards,
Klaas
Back when i bought it , i auditioned it together with a Treshold amplifier, i'm afraid i forgot what type it was.
At the time i preferred the Krell because the sound had a little more 'bite' .
Which one was better ? So many fools, so many opinions
In my enthousiasm about another (diy) amplifier i think i may have trashed the image of the ksa-50,
apart from loosing some braincells i like to think i've become a bit better at using the ones that still remain.
I built a Klone as well that never got past the experimental state, but it sounded fine and similar to the original.
IF i ever were to build a Klone again, i would be tempted to go with high(ish) rails
(i think Mark said previously that the Klone really started to sing at 42V rails)
and use enough outputs to keep dissipation per device within reasonable limits.
Does it make sense to own or build such an amplifier ?
Making sense is what has given us mp3, crappy $30,- dvd-players , etc.
To this date i'm still happy that Dan D'Agostino had the heart to design and build the KSA-50
Best regards,
Klaas
Attachments
I have never dealt with Jim Audio's KSA100 boards, haven't heard anything bad....
Price to refurb a unit would be quite costly...
Not to nit pick, but its D'Augustino, not Augustino, correct?
I know ... typing laziness .....
FWIW, I have a pair of jims KSA-100 boards. Very nice boards, highest of quality. If I remember correctly there is an error on the silkscreen somewhere, a diode or cap printed reversed or something. They are a little larger than an original board, but otherwise the layout of the pcb is almost a carbon copy of the original.
I have not build anything with the boards and have not examined them very closely, so I don't know if there are other problems with the boards.
If you like I can send you the BOM and schematics I received from jim when I purchased the boards.
Regards
Thanks and appreciated ...
Jacco never goes away.
He's part of the DIY Matrix .....
IF i ever were to build a Klone again, i would be tempted to go with high(ish) rails
(i think Mark said previously that the Klone really started to sing at 42V rails)
and use enough outputs to keep dissipation per device within reasonable limits.
I used 42V rails during the majority of the prototyping and testing of my board.
Iirc, i used 35V rails on my Klone.
I thought it sounded a bit tame compared to the original.Not necessarily worse.
If i would build a Klone i'd most probably use your boards, i used Jan's boards on my previous Klone.
I like the modular approach and improved grounding.
Best regards,
Klaas
I thought it sounded a bit tame compared to the original.Not necessarily worse.
If i would build a Klone i'd most probably use your boards, i used Jan's boards on my previous Klone.
I like the modular approach and improved grounding.
Best regards,
Klaas
The drop will depend on the design and actual capacity of the transformer itself.When I built mine I got a hellofadeal on a 1 kva single primary dual center tapped secondary surplus tranny for $60USD. It barely has any drop at all... Just a couple of volts. Yes, it is overkill...
Mark
Mark
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