How important the value of C21 (Egnater modules)?

This is the cap that passes the signal to the tonestack. I don't seem to find one that has the correct spacing and handles the voltage spec'ed for these boards at 1u.

I would imagine this fellow in many cases by-passed w. a 0 ohm resistor and in the case of Randall modules is not present at all that its function is not particulary tone specific.

Cheers,
Jonas

The purpose of a cap is to pass AC and BLOCK DC. The most common connection in a preamp tone stack is from the plate of the previous tube
to the tone stack of the next stage. To substitute a wire is to put the full plate voltage where it does not belong.
I don't have a schematic so this is a general statement.
Pins 1 and 6 are the plates. Unless it's some kind of cascode stage, plates
are not usually connected to anything directly.
You need to trace the connections on the cap to see where they go.

kc2eeb said:

The purpose of a cap is to pass AC and BLOCK DC. The most common connection in a preamp tone stack is from the plate of the previous tube
to the tone stack of the next stage. To substitute a wire is to put the full plate voltage where it does not belong.
I don't have a schematic so this is a general statement.
Pins 1 and 6 are the plates. Unless it's some kind of cascode stage, plates
are not usually connected to anything directly.
You need to trace the connections on the cap to see where they go.

Click to expand...

Cheers, it's between pin 3 of the raiser board (pin 2 of V2) and the tonestack. Anything going into the tonestack has to pass through this baby, just before the SW2 voicing switch which has no other components between it and the C21.

Which Egnater module is it?

C21 on the single channel Egnaters is the first component of the CF, and right before the Treble cap. It's probably bridged with a wire, or shorted directly to the Treble cap with a wire underneath the pcb.

:wink:

Thanks! Answers the question.

kc2eeb said:

Which Egnater module is it?

Click to expand...

Egnater single channel SL.

Pin 2 of the TUBE is one of the grids. See SacredGroove's post.
A .1 mfd cap will pass practically all of the audio bandwidth pertinent to the guitar if all of the signal is passing through it to the tone stack.
So shorting it may not make too much difference you can hear.
Of course, I don't have a schematic so I'm guessing.
To see if it's blocking DC, you 'd have to have the amp operating, in the play mode,
and then probe both ends of the cap with a DMM set to read DC, common lead of the DMM connected to ground and the volts (red) lead to probe.