His electrician friend joining this site would certainly help out as long as he speaks, or understands English. I have been following this thread and was surprised it went this long without someone else suggesting a conversion. Re-building the KSA into an Aleph might be out of reason for the owner, however it might not be out of reason for his electrician and there are many people in Germany that have built them and could probably help out. Certainly weighing the cost to repair the KSA vs. the cost to rebuild to an Aleph is worth the time and effort. In fact conversion to an Aleph may well indeed be far easier than repairing the KSA!
When I bought my KSA 80B it come from a guy near Boston that had traded it in for an Aleph 5. This was about 6 years ago and I told the guy then that I thought he was crazy for trading the KSA-80. Now see....I'm telling all Krell owners they are crazy..... My KSA 80 has had a new owner for a few years now. Thats how good the Alephs really are...I hold them in the highest regard!
Mark
When I bought my KSA 80B it come from a guy near Boston that had traded it in for an Aleph 5. This was about 6 years ago and I told the guy then that I thought he was crazy for trading the KSA-80. Now see....I'm telling all Krell owners they are crazy..... My KSA 80 has had a new owner for a few years now. Thats how good the Alephs really are...I hold them in the highest regard!
Mark
repair KSA 100
Hi
Thank for your answers.
Can your help me the parts for the driver board to find.
I search the transistors nummber: 24, 25, 26, 27
46, 48, 49, 51
look at the picture!
the sign on the transistors is:
24 - T A 9688 Y 5B
25 - T A 9688 Y 5B
26 - T C 2238 Y 5D
27 - T C 2238 Y 5D
46 - SI VPO 210N5 8928
48 - SI VPO 210N5 8928
49 - SI VNO 210N5 8918
51 - SI VNO 210N5 8918
Hallo,
Könnt ihr mir helfen die Bauteile von meinem Treiber Bord zu finden?
Ich suche die Transistoren oder die Bauteile mit den Nummern
24, 25, 26, 27 46, 48, 49, 51
Auf dem Foto habe ich diese Bauteile mit den Nummern bezeichnet.
Ich habe die komplette Bezeichnung von den Transistoren(Bauteilen) abgeschrieben.
24 - T A 9688 Y 5B
25 - T A 9688 Y 5B
26 - T C 2238 Y 5D
27 - T C 2238 Y 5D
46 - SI VPO 210N5 8928
48 - SI VPO 210N5 8928
49 - SI VNO 210N5 8918
51 - SI VNO 210N5 8918
Best ragards Alex helge
Vielen Dank
Hi
Thank for your answers.
Can your help me the parts for the driver board to find.
I search the transistors nummber: 24, 25, 26, 27
46, 48, 49, 51
look at the picture!
the sign on the transistors is:
24 - T A 9688 Y 5B
25 - T A 9688 Y 5B
26 - T C 2238 Y 5D
27 - T C 2238 Y 5D
46 - SI VPO 210N5 8928
48 - SI VPO 210N5 8928
49 - SI VNO 210N5 8918
51 - SI VNO 210N5 8918
Hallo,
Könnt ihr mir helfen die Bauteile von meinem Treiber Bord zu finden?
Ich suche die Transistoren oder die Bauteile mit den Nummern
24, 25, 26, 27 46, 48, 49, 51
Auf dem Foto habe ich diese Bauteile mit den Nummern bezeichnet.
Ich habe die komplette Bezeichnung von den Transistoren(Bauteilen) abgeschrieben.
24 - T A 9688 Y 5B
25 - T A 9688 Y 5B
26 - T C 2238 Y 5D
27 - T C 2238 Y 5D
46 - SI VPO 210N5 8928
48 - SI VPO 210N5 8928
49 - SI VNO 210N5 8918
51 - SI VNO 210N5 8918
Best ragards Alex helge
Vielen Dank
Attachments
to the electrician friends out there
Mark,
today I talked with Alex again. As it seems his electrician "friend" is rather somebody he met coincidentally. A hint from a friend who knows a friend who`s friend......You know what I mean.
Anyway, the guy just agreed to do a favour and to check the bias thing with the Krell. Unfortunately this misfortune happened and one channel is blown now.
Also probably this is embarrassing for him and that he is willing to compensate his fault, I really doubt that he agree to substantially change the Krell into another amp. (and besides this, from what I understood this is not really what Alex seem to want).
All what`s necessary to get the Krell working again are 2 matched sets of in total 16 power transistors and the resistors (and hopefully there is not more damaged) and this seems difficult enough.
To convert into an Aleph (or whatever else amp) it would not only require this but much more different parts, a PCB etc.. Additionally some mechanical changes likely are unavoidable. Finally this means MUCH more efforts than "just" to repair the Krell. For a DIYer all this would be completely acceptable but in this special case I believe it`s out of question.
By all means his "electrician friend" speaks English as I got told today and hopefully he`ll join in here when he´s back.
Meanwhile a question for the solid-state experts out there about the transistors used in this MKII driver board.
Alex copied all the numbers and letters which are printed on the transistors - I have no idea what kind of parts this could be ( at least not those of the middle and lower row)
upper row (on big blue heatsink only partially visible on the photo):
3x 452 MJE 15030
2x 452 MJE 15031
middle row (on 4 individual blue heatsinks):
2x T A 9688 Y 5B
2x T C 2238 Y 5D
lower row (on single blue sheet metal heatsink):
2x SI VPO 210N5 8928
2x SI VNO 210N5 8918
Somebody who has an idea what kind of transistors this are respectively who knows suitable replacement parts (in case one or more of them is damaged too).??
A drawing with values for the resistors follow soon (BTW: anybody who wants to have high resolution pictures from the two PCB sides of this MKII driver board PCB can email me)
Mark,
today I talked with Alex again. As it seems his electrician "friend" is rather somebody he met coincidentally. A hint from a friend who knows a friend who`s friend......You know what I mean.
Anyway, the guy just agreed to do a favour and to check the bias thing with the Krell. Unfortunately this misfortune happened and one channel is blown now.
Also probably this is embarrassing for him and that he is willing to compensate his fault, I really doubt that he agree to substantially change the Krell into another amp. (and besides this, from what I understood this is not really what Alex seem to want).
All what`s necessary to get the Krell working again are 2 matched sets of in total 16 power transistors and the resistors (and hopefully there is not more damaged) and this seems difficult enough.
To convert into an Aleph (or whatever else amp) it would not only require this but much more different parts, a PCB etc.. Additionally some mechanical changes likely are unavoidable. Finally this means MUCH more efforts than "just" to repair the Krell. For a DIYer all this would be completely acceptable but in this special case I believe it`s out of question.
By all means his "electrician friend" speaks English as I got told today and hopefully he`ll join in here when he´s back.
Meanwhile a question for the solid-state experts out there about the transistors used in this MKII driver board.
Alex copied all the numbers and letters which are printed on the transistors - I have no idea what kind of parts this could be ( at least not those of the middle and lower row)
upper row (on big blue heatsink only partially visible on the photo):
3x 452 MJE 15030
2x 452 MJE 15031
middle row (on 4 individual blue heatsinks):
2x T A 9688 Y 5B
2x T C 2238 Y 5D
lower row (on single blue sheet metal heatsink):
2x SI VPO 210N5 8928
2x SI VNO 210N5 8918
Somebody who has an idea what kind of transistors this are respectively who knows suitable replacement parts (in case one or more of them is damaged too).??
A drawing with values for the resistors follow soon (BTW: anybody who wants to have high resolution pictures from the two PCB sides of this MKII driver board PCB can email me)
Just Fix It.....
Just replace the output and driver transistors that are blown with MJ15024/25 and MJ15030/31 , replace emitter resistors that are blown (standard ceramic 5W types are good enough), run it up on a big variac one channel at a time and monitor bias current whilst doing so, and it should work just fine.
If you want to get really picky then match ouput transistors, but this is not strictly required.
I have repaired these in the past and the results are just fine, and long term reliable.
Once you have it working then you can ponder modifications, but in standard form these are a big horsepower amp that will drive any speaker without complaint, and the sonics are actually very good, even if not quite as nice as an Aleph, but still better than many, many other amplifiers.
Eric.
Just replace the output and driver transistors that are blown with MJ15024/25 and MJ15030/31 , replace emitter resistors that are blown (standard ceramic 5W types are good enough), run it up on a big variac one channel at a time and monitor bias current whilst doing so, and it should work just fine.
If you want to get really picky then match ouput transistors, but this is not strictly required.
I have repaired these in the past and the results are just fine, and long term reliable.
Once you have it working then you can ponder modifications, but in standard form these are a big horsepower amp that will drive any speaker without complaint, and the sonics are actually very good, even if not quite as nice as an Aleph, but still better than many, many other amplifiers.
Eric.
Alex,
Why do you bother about fets ?.
Typically you will find that the output transistors, maybe driver transistors and maybe emitter resistors only are blown - it is rare for damage to go further back.
Your friend should know what a variac is - use one to run up the amp whilst monitoring bias current one channel powered at a time.
If you need more info just ask.
Eric.
Why do you bother about fets ?.
Typically you will find that the output transistors, maybe driver transistors and maybe emitter resistors only are blown - it is rare for damage to go further back.
Your friend should know what a variac is - use one to run up the amp whilst monitoring bias current one channel powered at a time.
If you need more info just ask.
Eric.
Damaged Parts
Eric is correct,
The parts that get damaged or the or the NPN and PNP outputs emmiter reisstors and maybe the bias transistor. Do not get concerned about the front end of the amp.
In addition, many companies still sale these components. You just need to search the Internet for the companies. These are still a market for discontinued transistors.
Eric is correct,
The parts that get damaged or the or the NPN and PNP outputs emmiter reisstors and maybe the bias transistor. Do not get concerned about the front end of the amp.
In addition, many companies still sale these components. You just need to search the Internet for the companies. These are still a market for discontinued transistors.
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