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'Would you make any changes?'
Author:Stephen Keller (registered user: 6254 posts )
Date: Wed, Mar 14th, 2012 @ 11:10 ( . )

How about something like this:

Boost the anode voltage to the first gain stage as steve25 suggested [link]

Rebias the first stage a little warmer (say 1.5K on the cathode, whatever makes sense with the new anode voltage) and add some cathode bypass capacitance to taste. This will boost the gain of the first stage.

Just for grins rewire the volume control so it connects between the two preamp stages and connect the junction of C2 and C3 directly to the power tube grid.

As for the tremolo intensity. You might try bumping up R18 from 270K to 1M and reducing R24 to 250K (270K would be better if you can find a 270K pot). If I'm thinking about this correctly, that should give you finer grain control over a smaller range of intensities without upsetting the operation of the circuit.

J3 looks like it affords the highest input signal of the three. J1 and J2 appear to attenuate the signal by putting R3 in parallel with R4. Is J3 the Mic input?


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--* Would you make any changes?
3/14/2012 @ 12:19--dean owens
3/14/2012 @ 23:50----Stephen Keller
3/15/2012 @ 13:26------dean owens
3/17/2012 @ 16:16--------Stephen Keller
----------* So much better... new issues
3/21/2012 @ 14:16----------dean owens
3/21/2012 @ 15:05------------Stephen Keller
3/21/2012 @ 16:09--------------dean owens
3/21/2012 @ 16:34----------------Stephen Keller
3/21/2012 @ 16:37------------------dean owens
3/22/2012 @ 09:29------------------dean owens
3/22/2012 @ 09:57--------------------dean owens
3/22/2012 @ 10:14--------------------Stephen Keller
3/22/2012 @ 14:15----------------------dean owens
3/22/2012 @ 14:59------------------------Stephen Keller
3/22/2012 @ 16:07--------------------------Stephen Keller
3/22/2012 @ 15:40----------------------Paul Fawcett
3/22/2012 @ 16:17------------------------Stephen Keller
3/23/2012 @ 13:24--------------------------dean owens
3/23/2012 @ 14:22----------------------------Stephen Keller
3/26/2012 @ 00:09------------------------------dean owens
3/26/2012 @ 09:28--------------------------------dean owens
3/26/2012 @ 16:02----------------------------------Stephen Keller

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