Changing midrange freq on 5F6A

[yankeerob]

Hello to all and HNY,

I'm thinking of tinkering with the mid freq on a 5F6A based clone and am wondering if it's as simple as modding the value of a few components or more complicated and not worth the bother?

Many thanks

YR

[Chuck H]

It's always worth the bother to idealize your amp to your needs. Imagine making an amp so right for you that you only have to think about your playing and not your tone. I don't think that happens for most, but the closer you can get the better.

Changing the midrange tonality in that circuit can be done in several ways. You can change some coupling and bypass cap values and change the overall midrange tonality of the amp. Or you can adjust only the tonestack values so that the treble and midrange controls operate at different frequencies. You can change the NFB loop to get more midrange harmonics and distortion. You can change the phase inverter and bias to make the power tubes compress more, that usually sounds more midrangy. Speakers can dramatically alter the tone and efficiency of an amp.

What is it you want to hear that you don't have now???

For tweaking the tonestack you can use Duncans tone stack simulator. Available for free download here: http://www.duncanamps.com/tsc/

Use the "Marshall" tonestack for your 5f6a circuit. You will find that changing the slope resistor and pot values can be as useful as changing cap values.

Chuck