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volume between gain stages
volume between gain stages
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Old 8th July 2008, 11:38 AM   #1
blindbrett is offline blindbrett  Canada
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Default volume between gain stages

I am a working on converting a tube pa amp to use as a guitar amp. the amp is a fanon fma-35. I thought I would try adding a gain stage to give me some overdrive distortion for guitar so I ran the mic 1 output into the mic 2 input. ( out of one half of the 12ax7 to the mic 1 volume and then out into the other half of the same 12ax7) I put in a coupling cap as well. It works except the mic 2 volume now does not work very well. It has signal coming through when the vol is all of the way down and when you turn it up, it doesn't have the range of the other volume. When you turn it all the way up, it turns the volume off completely, no sound. The mic 1 volume control works like it should, no signal cutoff and full range of volume.I am still new at this and would appreciate any ideas on what i may have done. I don't have a schematic but I can try and clarify what I have wired if its not clear enough. I can put it back to stock but I would like to try and figure out the problem first.

thanks

Brett
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Old 8th July 2008, 02:22 PM   #2
nigelwright7557 is online now nigelwright7557  United Kingdom
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Default Re: volume between gain stages

Quote:
Originally posted by blindbrett
I am a working on converting a tube pa amp to use as a guitar amp. the amp is a fanon fma-35. I thought I would try adding a gain stage to give me some overdrive distortion for guitar so I ran the mic 1 output into the mic 2 input. ( out of one half of the 12ax7 to the mic 1 volume and then out into the other half of the same 12ax7) I put in a coupling cap as well. It works except the mic 2 volume now does not work very well. It has signal coming through when the vol is all of the way down and when you turn it up, it doesn't have the range of the other volume. When you turn it all the way up, it turns the volume off completely, no sound. The mic 1 volume control works like it should, no signal cutoff and full range of volume.I am still new at this and would appreciate any ideas on what i may have done. I don't have a schematic but I can try and clarify what I have wired if its not clear enough. I can put it back to stock but I would like to try and figure out the problem first.

thanks

Brett

I suspect there is so much voltage coming through you are getting break through on the pot.

Without seeing the cct I cant comment further.
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