Question For You Marshall Mod Guys?

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

How's the Marshall sounding now, John?

One of common mods done to those amps, and the JMP/JCM 2203/4 was to remove the 470p cap that is parallel to the 470k resistor between the first and second gain stages. That instantly took any brightness away.

The Marshall is absolutely great Erik....I'm waiting on Trace(Voodoo Amps)to send me one of his V Plex Transformers and a better choke...

Removing those caps across the 470Ks also loses some gain....Don't want to do that...Trace said the Output transformer and choke will make the amp perfect....The amp sounds great right now and I'm really wondering about the extra stuff I bought now and if it's really needed? Each time I play through my amp,I notice it's more open....Sustain and great note articulation with it now with any of my guitars.....I'm real happy with it overall..

[JeffB]

Re: Question For You Marshall Mod Guys?

mmmmm.....


cheese

[ErikH]

Re: Question For You Marshall Mod Guys?

How's the Marshall sounding now, John?

One of common mods done to those amps, and the JMP/JCM 2203/4 was to remove the 470p cap that is parallel to the 470k resistor between the first and second gain stages. That instantly took any brightness away.

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

On it's own, when the value of the capacitor increases, the lower frequencies let through increases.

When parallelled with a resistor, it forms a tone network. Increasing the value of either the resistor or capacitor now, will result in less lower frequencies going through.

I Love the Sozo caps as they've loosened up and smoothed out a bit more...Trace likes using the 715 Orange Drops....

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

You're right!! Nothing beats experience!! But it's fun to compare what you're ears tell you and what some theory tells you ...

Yes....That's pretty much where I was trying to go and agree with you brother...

[Marcel]

Re: Question For You Marshall Mod Guys?

I'm not going to get into the whole tone issue with caps....LOL...

I Just try different caps and different values until I happen upon something that I Like....That's the only thing that really matters!

You're right!! Nothing beats experience!! But it's fun to compare what you're ears tell you and what some theory tells you ...

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

On it's own, when the value of the capacitor increases, the lower frequencies let through increases.

When parallelled with a resistor, it forms a tone network. Increasing the value of either the resistor or capacitor now, will result in less lower frequencies going through.

Now you're talking my language!

Great info....Appreciate that...

[shredaholic]

Re: Question For You Marshall Mod Guys?

On it's own, when the value of the capacitor increases, the lower frequencies let through increases.

When parallelled with a resistor, it forms a tone network. Increasing the value of either the resistor or capacitor now, will result in less lower frequencies going through.

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

A ceramic cap is more nonlinear... don't ask me how this affect tone
I really like this article:
http://members.aol.com/sbench102/caps.html

I'm not going to get into the whole tone issue with caps....LOL...

I Just try different caps and different values until I happen upon something that I Like....That's the only thing that really matters!

[Marcel]

Re: Question For You Marshall Mod Guys?

A ceramic cap is more nonlinear... don't ask me how this affect tone
I really like this article though:

http://members.aol.com/sbench102/caps.html

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

in all seriousness, I wired up a brigth switch with a 120pf cap and 47pf cap and the 120 was brighter.

See now you're doing the same thing as me on this cap Scott?

The 120 pf is (I think) brighter than the 47 pf across the Fender bright switch...The 47 pf comes out of the circuit quicker on the volume pot as you volume up towards 10 also....The smaller cap only allows the "higher" frequencies to pass...And this stuff always confuses me! LOL

[STRATDELUXER97]

Re: Question For You Marshall Mod Guys?

I just had a non-coffee moment and realized that I was talking about variable resistors and not capacitors! duh! But go down anyway.

I Lowered that 500 pf mica down to a 330 pf already and I was on the right track,but thought I should check with you guys...Maybe I should try a ceramic there instead? It's grainier,but it might be less bright there also? Have to try it and see...

I'm waiting on one of Trace's Custom MM output transformers and choke..The amp rocks already overall even with the O.E.I in there....Trace talked me into spending more money "again".....Bastard....LOL

[Scott_F]

Re: Question For You Marshall Mod Guys?

in all seriousness, I wired up a brigth switch with a 120pf cap and 47pf cap and the 120 was brighter.

[Scott_F]

Re: Question For You Marshall Mod Guys?

or am I wrong... can't remember....

[Scott_F]

Re: Question For You Marshall Mod Guys?

I just had a non-coffee moment and realized that I was talking about variable resistors and not capacitors! duh! But go down anyway.