Just curious if any of you have played with increasing the 470k to ground on the mixer circuit and the effects of doing so....
It seems like an easy way to increase gain. As you increase the value of the 470k resistor to say to 560k, or even 680k, will it cause blocking distortion in V2?
Thanks!
Increasing gain at Mixer Circuit?
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Increasing gain at Mixer Circuit?
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Re: Increasing gain at Mixer Circuit?
Have you run out of amps to experiment on, Carl?!?
I build and repair tube amps. http://amps.monkeymatic.com
Re: Increasing gain at Mixer Circuit?
it's dead easy but you will need to adjust the cap to keep roughly the same mid response (though it will change some). Before you do any modding, just turn the normal channel volume to 7, this will increase the gain notisably
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From Euro tubes order yourself up a 12ax7 that tests out at a strong 1ma to the design spec for a 12ax7 of 1.2ma and you will not have to change out parts to have more gain , you then will also have a great tube to hear the effects of such with the cathode follower driving the tone stack!
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Re: Increasing gain at Mixer Circuit?
Thanks guys. I should have noted that I was referring to the 2203 circuit.... Doh! That would have given better context.... I ended up just using a 560k to ground at the mixer. I have a 1uf attenuated with a 1.2k across a 5.6k in the second stage. The first stage is stock. I have a 1uf across the 820 of V2a. PI couplers are .047. Rest is stock. This is a beastly 2203 build that someone commissioned from me. Using 7025 Chinese on V1, 12AX7B on V2, 12AX7E on V3. JJ EL34's (not EL34L's)
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Re: Increasing gain at Mixer Circuit?
Learning to learn...
Re: Increasing gain at Mixer Circuit?
an old trick with the four input amps is to turn up the volume of the channel you are not using to 7. This will give more gain, since the voltage divider of the channel mixer circuit changes from 470k/470k to ca. 470k/1M
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Re: Increasing gain at Mixer Circuit?
I've used a 1meg to ground and a 330k/500pf and that is a cool sound. I don't remember ever having problems with stability.
If you do have problems, just add a 10pf from the output of the mixer network to ground. That usually stabilizes anything after the volume pots. Or you can omit the 500pf for a different flavor.
If you do have problems, just add a 10pf from the output of the mixer network to ground. That usually stabilizes anything after the volume pots. Or you can omit the 500pf for a different flavor.
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Re: Increasing gain at Mixer Circuit?
heh, I do that too, never heard of others doing that.Roe wrote:an old trick with the four input amps is to turn up the volume of the channel you are not using to 7. This will give more gain, since the voltage divider of the channel mixer circuit changes from 470k/470k to ca. 470k/1M