Jump to content

removing cathode bypass?


wartoxin

Recommended Posts

  • Members

I was messing with an English Muff'n today (it's a pedal mmmkay) and thought removing the cathode bypass caps on the driven stages would give it more of a JCM800 tone. It did sound better at least in my quick tests. Less gain also but I wasn't focusing on that. I have a jet city combo which also has a cathode bypass cap I could try removing to get a less acidic tone. I've already tried changing the cathode resistor around.

 

Anyway is this a know or popular mod for any amps? Any thoughts on other things to try with the pedal or combo amp?

Link to comment
Share on other sites

  • Members

Cathode bypass caps (henceforth CK) are used to increase the gain of a given stage as well as behave as sort of a low frequency shelving filter.

 

A larger CK will give you more gain and lower lows. A lower RK will also increase gain, without affecting frequency response.

 

All of the above are certainly used in a variety of modifications.

Link to comment
Share on other sites

  • Members

 

I was messing with an English Muff'n today (it's a pedal mmmkay) and thought removing the cathode bypass caps on the driven stages would give it more of a JCM800 tone. It did sound better at least in my quick tests. Less gain also but I wasn't focusing on that. I have a jet city combo which also has a cathode bypass cap I could try removing to get a less acidic tone.
I've already tried changing the cathode resistor around.


Anyway is this a know or popular mod for any amps? Any thoughts on other things to try with the pedal or combo amp?

 

 

What?

Link to comment
Share on other sites

  • Members

Ive always wanted to try one of those pedals. Never got around to it. "tube" pedals seem to catch alot of hell, but there's something about them that I like.

 

Have you tried different tubes in it?

 

What voltage does it run off of?

 

With my Ibanez Tube King, a lower gain tube & a bigger power adapter (12 volts instead of 9) turned it into a better pedal. More balls. Less fizz. Easier to dial in.

Link to comment
Share on other sites

  • Members

Ive never seen anything , as far as mods for them go. Could be an interesting pedal to f*ck with. Try some different tubes before you get crazy with the soldering iron. Maybe some t7's or u7's.

 

Im hoping to get myself a Mesa Vtwin or Mesa Bottle Rocket sometime in the next year. Havent tried the bottle rocket, but loved the V twin when I tried one years ago.

Link to comment
Share on other sites

  • Members

To me, just randomly removing the cathode bypass cap is not a very good way to mod a preamp. You may happen to randomly get what you're after but more likely you won't.

 

The "secret" trick to modding a preamp, which hardly anyone seems to understand, is to bias the valve to get the type of overdrive character you want...Tweak the cathode bypass cap to give the filter you want. And for a Marshall vibe use a Marshall tonestack...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...