Benson Preamp  [traced]

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Re: Benson Preamp

Postby bmxguitarsbmx » 16 Sep 2019, 18:37

andy-h-h wrote:Any suggestions as to what capacitors should be used to get the same response using a 1M pot instead of 2M or a dual 1M? :hmmm:

Thanks.


Scale all resistors by 0.5, all capacitors by 2. I do mean all resistors and capacitors in this network, including gain pot.
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Re: Benson Preamp

Postby knottypine » 29 Sep 2019, 01:34

atalas wrote:
knottypine wrote:Is there a suggested voltage for Q1?

Pedal sounds pretty nice in front of my Music Man with Bass, Mid, and Treble set to 5


~5V, or if you have a bunch of J201, set the source resistance to 12K and swap JFETs until you get one sit at 5V at the source. This will achieve a closer sonic result than just changing the source resistance to achieve 5V for whatever JFET is in there now.



Could someone mock up a stripboard layout with a trimmer for Q1? ✌️
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Re: Benson Preamp

Postby atalas » 09 Oct 2019, 04:59

knottypine wrote:
atalas wrote:
knottypine wrote:Is there a suggested voltage for Q1?

Pedal sounds pretty nice in front of my Music Man with Bass, Mid, and Treble set to 5


~5V, or if you have a bunch of J201, set the source resistance to 12K and swap JFETs until you get one sit at 5V at the source. This will achieve a closer sonic result than just changing the source resistance to achieve 5V for whatever JFET is in there now.



Could someone mock up a stripboard layout with a trimmer for Q1? ✌️


You could just bodge in a trimmer instead of the 12k. Maybe use short little jumpers, or even make it an external control.
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