Rat Feedback Loop EQ

[seedlings]

In the ProCo Rat, there are two filters in the feedback loop.  The 560R-4.7uF is tuned to 60Hz gain of 267, while the 47R-2.2uF is up at 1500Hz gain of 3191.

Does this mean there is partial boost from 60Hz to 1500Hz, and a full boost from 1500Hz up, or do they interact so that the knee is somewhere between 60 and 1500Hz?

Thanks!

CHAD

[seedlings]

From reading about that Ruez mod, I gather 60Hz to 1500Hz has 267 gain and 1500Hz up is 3191 gain.

CHAD

[PRR]

> 1500Hz gain of 3191
> boost from 1500Hz up

1500 times 3191 is 4.8MHz gain-bandwidth.

The LM308 doesn't have that much gain-bandwidth.

It must be dropping before 1.5KHz.

The dual-RC adds a little change in the lowest octave.

http://www.diystompboxes.com/smfforum/index.php?topic=92931.0

[seedlings]

1500 times 3191 is 4.8MHz gain-bandwidth.

So the highs keep getting "rolled back" as gain increases... a bandpass filter.

I'm using an LM833n with gain-bandwidth of 15MHz, so in theory this would limit frequency to 4700Hz.  Thank you for introducing me to a new term!

CHAD

[WGTP]

There is some low-mid/bass boost with the 2 "leg" setup.  Or, you could think of it as a low-mid dip.