Don's Amp Pix

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Don's Amp Pix

Postby Shannon Parks » Tue Jun 21, 2005 6:42 am

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I'm buzzin

Postby dhuebert » Wed Jun 22, 2005 9:46 am

Thanks, Shannon
Now for a question: The preamp buzzes, If I disconnect the grid on the second triode the buzzing stops. Any ideas? For reference:

http://www.diytube.com/forumpix/sch2.jpg

All the grounds in this circuit are tied to the input jack, this reduced the buzzing by about 80% but grounding the second grid stopped it totally.

Don

BTW some changes since this schematic
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Re: I'm buzzin

Postby Shannon Parks » Sat Jun 25, 2005 8:28 am

dhuebert wrote:Thanks, Shannon
Now for a question: The preamp buzzes, If I disconnect the grid on the second triode the buzzing stops. Any ideas? For reference:

http://www.diytube.com/forumpix/sch2.jpg
...
BTW some changes since this schematic


Hi Don,

Looking good! Could you email me the updated schematic? Some voltages with tube complement written on there would be great, too.

Shannon
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Have you learned patience?

Postby dhuebert » Mon Jul 04, 2005 9:39 pm

New schematics in 2 weeks or so (on holidays)

Don
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And Now... Schematics!

Postby dhuebert » Tue Jul 19, 2005 11:16 am

http://www.diytube.com/forumpix/power_amp.jpg
http://www.diytube.com/forumpix/power_supply.jpg
http://www.diytube.com/forumpix/preamp2.jpg

When I removed the paralleled input tube the buzzing stopped. My guess is that if the tubes are not exactly matched, something like a ground loop will occur, trying to force a node to two different voltages.

Don
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