Will taking the signal from the input and feeding it to 3 different input tubes in a multichannel design unnecessarily load the signal? If the signal is getting loaded, is there a way to buffer it internally before it gets to the gain stages?
The input will go like this:
INPUT---through 68k resistor to grid of 12AX7 Clean Channel
Jumper from the grid of the 12AX7 to grid of EF86 Clean Channel.
INPUT---through 68k resistor to grid of 12AX7 Dirty Channel
Input to 3 Gain Stages
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Andy Le Blanc
- Posts: 2582
- Joined: Sat Dec 22, 2007 1:16 am
- Location: central Maine
Re: Input to 3 Gain Stages
just watch out for the total impedance that is seen by the instrument and the
tube. You could go as far as to use a RC circuit for each grid to control what
each "see's" and to pre-shape tone, to provide a measure of isolation for each, but there will be an insertion loss.
tube. You could go as far as to use a RC circuit for each grid to control what
each "see's" and to pre-shape tone, to provide a measure of isolation for each, but there will be an insertion loss.
lazymaryamps
Re: Input to 3 Gain Stages
Another idea might be to voltage divide the output of the clean AX7 and use that to drive the dirty AX7 - they'd be out of phase, but without knowing the rest of your design I don't know if that would be a problem. The pentode shouldn't be much of a load. I've never tried it, but I would think you would be able to piggyback the EF86 to either triode grid without penalty. Others with more experience with EF86s might disagree...
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