I've read about the MV on this forum but I'm not sure how to wire it
Also I have 3x47uF + 3x22uF on the powerfilters. I cannot get one 33uF for a long time so would it be too far of using a 47uF instead of the 33uF as on the layout ?
i used three 20u and three 40u which i think is "francesca" spec.
im not sure about this master you show.
the ones i have have seen are pre phase inverter or post phase inverter like on marshalls. maybe someone will chime in here that knows whats up.
* Connect the 0.1uf cap going to the phase inverter in the original circuit to the "high" terminal of a new 1M-ohm pot (mount this on the front or rear panel). The original 0.1uf cap will now be connected between V2 pin 1 and the high terminal of the pot. Looking at the back of the pot, the "high" terminal will be the one on the right side.
* Connect the "low" terminal of the 1M-ohm pot to star ground. Looking at the back of the pot, the "low" terminal is the one on the left side.
* Connect the "wiper" of the 1M-ohm pot to another 0.1uf cap and connect the other end of the cap to the 1M-ohm resistor in the phase inverter (the same one that the original 0.1uf cap connected to). The wiper is the terminal in the middle. This 0.1uf cap will then be connected between the wiper of the MV pot and the 1M-ohm resistor that you removed from your layout (the "lefthand" 1M resistor).
This makes a simple voltage divider between the V2 output at pin 1 and the phase inverter.
A much better way is to use a dual pot between the output of the phase inverter and the input to the EL34s. This is more complicated, but it won't act as a low-pass filter like the simple MV will (it will likely change your tone as you dial it down in level).
No problem using the 47uf filter caps. The values of the filter caps are not critical and certainly you won't hear a 20% difference from nominal.
894]http://www.pichotel.com/pic/16028B31e/72478.jpg[/img]
