Peavey 300 Series Monitor Equalizer Amplifier - EQ Bypass

[TomCarlos]

Fellow MEF members....

Our good friends at Peavey sent me the schematic for the Peavey 300 Series Monitor Equalizer Amplifier - see below.

I picked up this unit yesterday. It unit works!! But, the slider controls are crusty and very difficult to move. I hit them with some cleaner and lubricant. They are still difficult to move freely and I am afraid they might break at any point in time.

So my question is, "if I should need" or "want to" bypass the EQ section (with a switch on the front panel), how would you do it?

My guess is that you need to break the connection that goes to the EQ, then hang a resistor off U4B Pin 3 to ground and switch out R20 for some other value and take that to ground?

I am looking at U1A as an example and trying to figure out what the gain should be for U4A if the EQ was not there.

Thanks !!







Peavey_Series_300_Monitor_Preamp.pdf

[Jon Snell]

The simplest way is to cut both points X.
Connect pins 1 & 3 together, (points X).
Connect point X to X.

That will dissable the graphic.

[TomCarlos]

Thanks Jon...

It looks like you are suggesting that U4B be configured as a Voltage follower. So we'll have 0 ac gain on that stage? That would make sense!

[Jon Snell]

Thanks Jon...

It looks like you are suggesting that U4B be configured as a Voltage follower. So we'll have 0 ac gain on that stage? That would make sense!

Correct, there should be plenty of gain from the other stages to compensate but if needed U4B could be configured to give say 12db of voltage gain but I don't think you will need it.