Preamp question

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C Moore
Posts: 1266
Joined: Mon Oct 22, 2007 9:28 am
Location: USA, California, 94585

Preamp question

Post by C Moore »

I am working on an old PA head that I have gutted.
I was thinking of using the Ampeg M-12 schematic. I was planning on using just one input to the first triode, PI, Tremolo, and of course 2x6V6. Would there be any advantage in using that other half of the triode that was formerly used for a second instrument.?
I was wondering if there is any wisdom in another gain stage, after the "tone stack" and before the PI.?
Thank You

http://www.webphix.com/schematic%20heav ... 12_6v6.pdf
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Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: Preamp question

Post by Andy Le Blanc »

The PI is what makes the gain here, unless you used a tone stack with a large
insertion loss and had to make of for it with another gain stage.
lazymaryamps
C Moore
Posts: 1266
Joined: Mon Oct 22, 2007 9:28 am
Location: USA, California, 94585

Re: Preamp question

Post by C Moore »

Andy Le Blanc wrote:The PI is what makes the gain here, unless you used a tone stack with a large
insertion loss and had to make of for it with another gain stage.
Hey Andy -
I kind of follow what you are saying. So just leave it the way it is. Maybe I can add a bright switch (ala Fender) and maybe a cathode cap by-pass switch (is that what a "Fat Switch" is.?)
I was also going to use the Trem circuit of course.
Maybe I should ask around before I do this. I have never even heard one of these before. I have ONE friend that has one, and he says it is "great".
Any body have an opinion on this circuit...?
I am trying to stick with the octal sockets that are in the chassis. So, this circuit with the 2x6V6 (that is what the original amp had) and the Trem seemed like a good idea.
Thank You
Last edited by C Moore on Sat Jan 22, 2011 6:20 am, edited 1 time in total.
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: Preamp question

Post by Andy Le Blanc »

I had a rig based on those, made the feedback variable,the dirt was nice
got me to explore other paraphase inverts.
lazymaryamps
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