Bassman AB165

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Mant
Posts: 16
Joined: Sun Jun 24, 2012 3:22 pm
Location: Silverlake

Bassman AB165

Post by Mant » Wed Sep 13, 2017 7:14 am

I have a Bassman AB165 and was staring at the schematics and comparing to the AA864.
Two questions, is there a sonic difference between doing the voltage divider verses negative feedback on the extra gainstage in the bass channel?
And how about the normal channel mixing in post that gainstage (AA864) vs pre that stage(AB165)?

Thanks
Rob
You sound more Like you do now then you did just a little while ago.

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martin manning
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Re: Bassman AB165

Post by martin manning » Wed Sep 13, 2017 10:41 am

In a word, yes. This write-up has been out on the web for a while, and it has some commentary on the differences and possible mods: http://acruhl.freeshell.org/mga/main/AA ... AB165.html
An odd thing with the AB165 is the second stage of the Normal channel takes its power from the 4th supply node, which puts some DC on the grid circuit of the mixer stage. Relocating it to the 5th node will reduce noise.

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