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Old 2nd October 2006, 07:44 PM   #1
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Join Date: Oct 2003
Location: San Jose
Default Aleph30 Turn-off Thump

Hello everyone,

I built and absolutely love my Aleph30 based on BrianGT's boards. The amp runs and sounds great, however I'm concerned about a turn-off thump I'm getting on my speakers.


I'm using 6 IRFP144's per channel with standard Aleph 30 biasing.

Question: Where's a good place to start looking for a fix? Has anyone else experienced this issue and has been able to resolve it?

Thank you!

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Old 2nd October 2006, 09:04 PM   #2
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I don't think I can help, but I can add that my Aleph 30 with brians boards does the same thing. I have not had a chance to look at the output with a scope. I am tied up with the AX and the 30 just sounds so good.
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Old 3rd October 2006, 12:13 AM   #3
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Location: Toronto, Canada
Mr. Pass once mentioned this in passing about the turn off thump:
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Old 3rd October 2006, 03:27 PM   #4
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Thanks Dennis for the post refrence!

I believe my off-set between + and - supplies are very low, like less than .1VDC. I'll measure again and also measure the offset during power down.

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