Timdalf the Grey's WOPL 1000

Northwinds

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laatsch55 said:
I think they were stressed to begin with, (the outputs) was just north of 385 when they went......when I brought it up on the DBT the bulb wasn't quite as dim as they go so I was keepin a pretty close eye on it. The right channel heatsinks were getting real hot real quick....so my meter was all over the place lookin and I was touching every heatsink on the board and things were just too hot to be normal then ........POOF......Tim had to re-up on rail fuses about two weeks ago........that was also a clue....
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I wonder if this could be the same issue as what happens with Michele's amp Silvara?

EDIT: She messaged me saying her local tech looked at it

"So my tech came over to my house last Friday. He tested the DC on Silvara with no load on it. Tested excellent. Then he added a light load and increased it slowly over about 20 minutes- nothing went wrong. I'm going to leave it running for longer while I work close by and see what happens but no problem as yet"

I find it hard to believe it ran stupid hot one minute then fixed itself???
 
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laatsch55

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If you had a faulty output that went open instead of short....it would appear to have fixed itself....but you are short one output. Or a flaky solder joint in the bias circuit...
 
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Replaced the 2-21196's and the 1-21195 and all is well. Everything running much cooler.

One thing deserves mentioning here, if that happened to a stock board I'd still be replacing components ON THE BOARD, not to mention the backwall problems, thanks Joe!! Your redesign really helps, even in catastrophic failures!!

Sir Joe, how does an output "leak"??
 
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laatsch55 said:
Rail fuses on the right channel went nuklar....two 21196's and one 21195 are toast...
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That's what the fuses looked like in my CV's several times before Jer suggested I bump them up to 4A. I burnt one so bumped them to 5A 250V fastblos and relied on my ears with Silvara. Have not smoked anything in them yet but the Clair Bros 700 may change that LMAO
 
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The 3 emitter resistors , on the 3 outputs that were blown , were also bad. In the hundreds of thousands of ohms, with one being megohms....they are now replaced...
 
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Northwinds said:
That's what the fuses looked like in my CV's several times before Jer suggested I bump them up to 4A. I burnt one so bumped them to 5A 250V fastblos and relied on my ears with Silvara. Have not smoked anything in them yet but the Clair Bros 700 may change that LMAO
Click to expand...

The 700 can easily smoke the 5A fuses. When I had CV D9s I used the 5 amp fast blow and that seemed to be the right fuse size for them, and I would blow them from time to time on a stock but recapped 700.

Seemed that putting a 6 amp in there might lead to a real speaker failure, but I never tried more than 5.
 
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Gibsonian said:
The 700 can easily smoke the 5A fuses. When I had CV D9s I used the 5 amp fast blow and that seemed to be the right fuse size for them, and I would blow them from time to time on a stock but recapped 700.

Seemed that putting a 6 amp in there might lead to a real speaker failure, but I never tried more than 5.
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That's exactly what I plan to do with these, we are leaving shortly to pick them up. I only have the M-504 that I fully trust right now. The Clair Bros 700 works but I would be tempting fate unless I ran fuses in the speaker wires, when I use it, it's only hooked up to Infinity RS-1 bookshelfs. The Aerosmith 400 Lee gave me runs like a raped ape but it's just running Bose speakers in the garage so if it goes DC oh well, tag sale Bose are easier to lose then these
 
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If your CV's have the fuse mounted in the crossover you will be good to go for protecting them in case of massive amp failure and DC out. I know as I've done it several times before going down the WOPL path. Fuses do work to protect drivers. Empirical data has told me so. DC is so high out of a blown 700 the fuse melts instantly.

And I know there are caps in place for mids and tweets so they are protected from DC. The woofer is the only one in danger and the fuse will protect it but understand if you are nervous about it.
 
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An interesting problem with Timdalf's WOPL. I'm getting a truncated positive sinewave waaaaaaay before it should be. The scope shot and AP shot are at 350 wrms into 8 ohms. the clip on the upper half of the B channel started at 360 watts and as it warmed up the clip threshold kept dropping, it got as low as 240 watts.

Rail voltage at no load is 103.5, rail voltage at the scope shot is 82.3.

This amp suffered some output failures when Tim's fan went dead during some very loud AC/DC and he didn't notice the fan had quit. It got VERY HOT, the thermoswitches were either too slow or are no longer in their advertised ranges.
 

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laatsch55 said:
An interesting problem with Timdalf's WOPL. I'm getting a truncated positive sinewave waaaaaaay before it should be. The scope shot and AP shot are at 350 wrms into 8 ohms. the clip on the upper half of the B channel started at 360 watts and as it warmed up the clip threshold kept dropping, it got as low as 240 watts.

Rail voltage at no load is 103.5, rail voltage at the scope shot is 82.3.

This amp suffered some output failures when Tim's fan went dead during some very loud AC/DC and he didn't notice the fan had quit. It got VERY HOT, the thermoswitches were either too slow or are no longer in their advertised ranges.
Click to expand...
Try lifting one end of D9 Lee if it is a RevE board to help you troubleshoot it.
 
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laatsch55 said:
Much better, but still not what we are used to..

Symmetrical clipping occurs at 400 wrms now, rail voltage down to 79.9...this all at 1khz
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You are hitting the rail voltage with the peaks Lee...scope shots show approx. +/-80V which is what you measured for the rail. You cannot get more than the rail can supply.
 
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