question about an amp mod??

[spiderman2812]

I have a jcm 2000 tsl 100 head and was wondering if this same mod that applies to distortion pedals to smooth them out would work also on the volume pots on the lead and crunch channels of the amp. Or if you all know of any mods that can help me get rid of the buzziness in the distortion of the amp i would greatly appreciate it. I'm looking for a fat crisp bass overdrive sound. Thanks Kevin.

"Refine" your pedal and smooth the tone out




A Jake Nagy special! Put a smallish value capacitor on the output lugs of your volume pot (from signal to ground) to clear up the high end "buzz and hash" from your pedal and give it instant smoothness!

Try different values from 220pf to .0015uF or even larger values depending on the amount of high frequency content you want to remove.

[Ronsonic]

You can tack caps in there if you like. What a crap way of doing things.


You'd be better off finding and lifting things like "bright caps" that are added between the wiper and hot side of a pot, I believe there's one on the gain control. THere will be others. Find a schematic and see where changing a value will make the difference. Where you see things like a cathode bypass cap that is 1uF or less, make it 4.7uF or more. Reducing the value of the slope transistor in the tone stack could help.

I wouldn't bother doing more than clipping the caps on the gain and volume control. These amps are not for the amateur to be working on.

Now, why on earth do you want to do this? Not exactly my favorite amp, but that's why I don't own one. How much bass do you need? What the heck kind of music is this and where are you playing that the thirty some knobs and switches won't do?

Ron

[spiderman2812]

It just seems like the crunch channel and lead channel are aweful buzzy and i've been doing a little research and have been hearing that there are mods that can be done to smooth it out. Thanks for the advice.

[BD13UK]

Hi,
Not sure about this particular Marshall circuit but I snipped the clipping diodes on a Marshall JCM 900 to get the 800 sound without that fizziness inherent in the 900, there is info somewhere on the net about this stuff but I can't recall where, maybe www.blueguitar has some info.

[Sir H C]

Sometimes it is just the tubes.  Some tubes are higher gain than others and often are "fizzier".  You can try using lower gain tubes such as 5751s and 12AT7s for the 12AX7s in the high gain stages.