additional gain stage

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Ivabiggun
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additional gain stage

Post by Ivabiggun » Mon Sep 14, 2009 2:22 am

Hi, can someone send me a few links on adding another gain stage to the MV amp. It's actually going into a JCM800 50 watt circuit. I have my basic design down but I would like to get a little more info on incorporating it as the first stage with the others to follow. I want to make sure I don't design to much gain into it as I know the perils of adding a lot of gain in one stage. As always, thanks to everyone here for all the help over the last few years.

Iva
"Sign zee papers, old man"

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gutpile
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Re: additional gain stage

Post by gutpile » Mon Sep 14, 2009 12:00 pm

I added quite a bit of gain by changing the 10K on the left hand side of the board to a 2.7K which in turn made me had to change the NFB from a 100K to 27K... I also changed the bright cap to a 500K... I have noticably more gain that was relatively painless :D ... Good Luck!

Mike
Metro Clips
Amps:Metro-(JTM45,50w,'69 spec 100w,45/100,100wMV,Bluesbreaker Combo),Orig. 65BFTR
Axes:LP Custom,Am. Strat,Am. Tele,61 SGRI

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LP Freak
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Re: additional gain stage

Post by LP Freak » Tue Nov 17, 2009 10:13 pm

I tried this. It has a bit more gain, but the bottom end seemed to get really floppy. Any idea hoy to tighten it up without loosing the low end?

erigm
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Re: additional gain stage

Post by erigm » Sat Feb 19, 2011 1:25 pm

If you're going for tighter bass try swapping the 2k7 (the one that replaced the 10k) with a 4k7 bypassed with .1uf or .2uf. That should give you about the same amount of distortion but with a tighter percussive sound.

Some people like swapping the first stages cathode cap of .68uf with .47uf, so you might try that as well.
erigm

vlad
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Re: additional gain stage

Post by vlad » Sat Jul 09, 2011 9:09 am

Do you want to add another tube? Or convert the CF to a gain stage?

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