Tube preamp EQ bypass switch

[joedonchev]

Hi,
Can I put a switch to bypass the EQ section of a tube preamp (ON-ON, 6 legs switch I guess?)?

Here is the EQ:

I can provide the full schematic if needed.

 

[rayma]

A SPST switch, connected between the left end of C6 and the top of VR1, will bypass it.

 

[joedonchev]

@rayma

left end of C6 and the top of VR1

Do you mean between the 2 red dots? R6 is part of the EQ, right?

SPST switch

Do you mean to break the line between VR1 and the .047 cap at the top left, disconnect the VR1's top end?

 

[rayma]

Add the SPST switch between the two red dots.
No other changes at all.

Preferably, when in bypass mode, keep the two tone controls both at full CW rotation.

 

[joedonchev]

@rayma Great, thank you very much! I will try that!

 

[stocktrader200]

Replace R5 with 250 k pot.
Wiper to switch. Use pot to equalize the bypass level with the tone level.

 

[joedonchev]

@stocktrader200
Thank you!

Replace R5 with 250 k pot.

Because the output may be too hot without the EQ?
Maybe I can put a jumper instead or R5 and try different resistor values, around 100k?

Wiper to switch.

What that means? 🙂

 

[Zung]

... Call it free overdrive, and move it to the "Instrument..." section.

 

[joedonchev]

@Zung
It is actually a guitar tube preamp, Peavey Rockmaster Preamp's clean channel. 🙂
But yes, I would like to keep it clean. There are 2 more channels, overdriven.

Oh, now I see there's a dedicated section for instrument amps under Live Sound.