Champ mod questions

[ncusack]

So i guess that explains the angel super champ schem having a 0.68uf and a 25uf switched on the first cathode. They would act like 3 different tones then a 25uf would be bassy the 0.68 would be treble and id assume just the resistor would be something in between.

If I were to put the cap variations on the first input instead of the second and had the feedback switchable would it end up roughly the same?

[captntasty]

In the Angela schematic the switching is one cap or the other. The 2k7 resistor (your particular design may have a different value R - maybe 1k5? really unimportant as this just gives you an idea of what can be done) is necessary - always! The caps are optional - both the values and whether they are there at all. If you were to use the proper switching scheme you could have 3 options 1) just resistor to ground=less gain, very clean 2) .68uf or .47uf parallel to resistor=emphasized high freq more gain and less bass 3) 22uf or 25uf parallel to resistor=full freq range, more gain and more bass.

[ncusack]

In the Angela schematic the switching is one cap or the other. The 2k7 resistor (your particular design may have a different value R - maybe 1k5? really unimportant as this just gives you an idea of what can be done) is necessary - always! The caps are optional - both the values and whether they are there at all. If you were to use the proper switching scheme you could have 3 options 1) just resistor to ground=less gain, very clean 2) .68uf or .47uf parallel to resistor=emphasized high freq more gain and less bass 3) 22uf or 25uf parallel to resistor=full freq range, more gain and more bass.

So with this idea a good mod starting point would be to say wire in a .68uf and a 22uf using something like a 3 position dpdt switch and mabey have the NFB on a switch as well.

[captntasty]

a .68uf and a 22uf using something like a 3 position dpdt

it could be done with a 3 pos dpdt - pay attention on this switch to which positions are actually making connections - it's different than you might think. If you are always going to have a cap in circuit you could use a 2 pos dpdt... the 22uf would always be in circuit, the .68uf could be placed across one side of the switch (Mind your polarity)with a jumper across the other side, the switch commons would come from the 22uf (on the board)and then off to ground. When you switch the .68uf in series with the 22uf your total capacitance would be about .66uf. There are calculators online that figure series or parallel capacitance and resistance - you can do some interesting things in this way. When it is switched to the other side (through the jumper) you get your 22uf. And with a 3 pos there is most likely a way to get the third option removing both caps - I would have to play around with it though. NFB on a switch would work well - I've even experimented with putting it on a pot for adjustable NFB.