"Mysterious" wire in Krell KSA-50MkII - diyAudio
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Old 21st July 2014, 01:08 PM   #1
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Default "Mysterious" wire in Krell KSA-50MkII

Hi everyone,

I have a small problem with my Krell, a yellow wire broke off the PCB and I'm still puzzeled about that does that wire actually do?

It comes from the positive speaker connector, has a R8 resistor under a piece of heatshrink, goes through something that looks like a fuse holder and ends on the main PCB.

The question is: Why is it only on one channel? I'm sure that's a factory job as I saw more KSA50's with the same thing.

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Old 21st July 2014, 01:11 PM   #2
rayma is offline rayma  United States
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Looks like a patch for an offset problem.
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Old 21st July 2014, 01:13 PM   #3
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Could be, I heard it too that has something to do with fixed offset.
But would it leave the factory with something like that? It's also on one channel only.

The yellow wire also goes through this, I have no clue if this is a fuse holder?

Edit: Turns out to be a switch that needs a key to operate:

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Last edited by czolgista778; 21st July 2014 at 01:29 PM.
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Old 21st July 2014, 01:52 PM   #4
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I just heard that it could be a workaround for a possible problem when Krell replaced the fuses with relays in the MkII version as the amp could become unstable before the relays would switch the speakers on and that's why they added the R8?
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Old 21st July 2014, 02:12 PM   #5
SonyFan is offline SonyFan  United States
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Hate to be negative but I would not be happy if I forked over the cash for a Krell and found a kludge of a fix like that. Whatever you do, I wouldn't reconfigure anything just fix it exactly. It is obviously there for a reason, they didn't just feel like giving you a free resistor and needed a place to put it.
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Old 21st July 2014, 02:18 PM   #6
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Don't forget 20cm of a fancy yellow wire and a switch
Yes, of course it will be brought back to original condition.

If I only could get in touch with Dan, maybe he could explain the purpose of that yellow wire once for good.


//
Sorry to go a bit off topic but I'm planning to give the Krell some good TLC and was wondering how important for the sound the small 1000uf ROE caps in the feedback loop are and what to replace them with?

Last edited by czolgista778; 21st July 2014 at 02:26 PM.
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Old 21st July 2014, 02:30 PM   #7
YashN is offline YashN  Canada
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Switch, key... it's for detonation.
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Old 21st July 2014, 02:30 PM   #8
SonyFan is offline SonyFan  United States
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Quote:
Originally Posted by czolgista778 View Post
Don't forget 20cm of a fancy yellow wire and a switch
Yes, of course it will be brought back to original condition.

If I only could get in touch with Dan, maybe he could explain the purpose of that yellow wire once for good.


//
Sorry to go a bit off topic but I'm planning to give the Krell some good TLC and was wondering how important for the sound the small 1000uf ROE caps in the feedback loop are and what to replace them with?
I fear losing my head for making a capacitor suggestion, every post below this will probably tell me I'm wrong, but I like Nichicon caps. Particularly the Fine Gold series, I have heard them all- including Elnas (Cerafine, Silmic, Silmic II, they all sound harsh to me) and always come back to the Nichicon FG (Fine Gold) and FW (power supply FG equivalent in bigger values/voltages for when you need them). They sound great from the moment they go in, other caps I have tried not so much. People swear they need to "break in" but I think that you just get used to the sound, better or not.
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Old 21st July 2014, 04:39 PM   #9
SonyFan is offline SonyFan  United States
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Quote:
Originally Posted by YashN View Post
Switch, key... it's for detonation.
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Old 21st July 2014, 04:42 PM   #10
Mooly is offline Mooly  United Kingdom
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Quote:
Originally Posted by czolgista778 View Post
I just heard that it could be a workaround for a possible problem when Krell replaced the fuses with relays in the MkII version as the amp could become unstable before the relays would switch the speakers on and that's why they added the R8?
It could be a feedback take off point after some kind of series interrupt device, a fuse, relay.... whatever.... with a view to maintaining some DC feedback when said device operates. But your circuit as drawn shows no such components.
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