Presence control .1uf .68uf

[RockinRocket]

Im interested in using a switchable .1uf and .68uf cap on the presence control of the first version of the Jmp presence control circuit that has DC across the pot.

My question is using the MK1 circuit that has DC across the pot and using the later MK2s .68f capacitor can I acheve the same frequency sweep as a normal MK2 non DC circuit?

The first circuit uses a 5k linier pot and a .1uf cap. The MK2 presence circuit uses a 25k linier pot, 4k7 to ground and a .68uf cap.

[pdf64]

The max setting of either should give the same response.
The min setting may be slightly different but I doubt it's noticeable.
The 25k control may not have much variation over 0-66% rotation, then it all happens in the last bit, up to max.

[Reeltarded]

The first is the good one, and the .1u is the best choice.

Better off adding a slope control where shaping means more. It's just another way of thinking about something you didn't ask for.

[RockinRocket]

I was planning on adding a few switches that will switch out the few values in a 50 watt jmp. I was just hoping that the .68 on a switch would effectively give me the same frequency range as if I had the Mk 2 circuit. In a perfect world id just switch In and out a dual ganged 5k/25k pot

[Reeltarded]

Just use a .1 and put a .56 on a switch. Most of both worlds. You will not like the big one after you flip the switch about 10 times.

I can see the future. Sorry.

[RockinRocket]

Just use a .1 and put a .56 on a switch. Most of both worlds. You will not like the big one after you flip the switch about 10 times.

I can see the future. Sorry.

Putting the caps in series on a switch? This will eliminate or reduce switching noise? And/or have a effect with no DC on the switch?

[Reeltarded]

Paralleled. The .1u is the default and installed just like stock. The .56u is in series with a switch and para over the .1u.

You can add a 10k trimmer in that .56 path to tune how much action there is from that portion of the signal. Partial bypass idea. I don't care for the .68 pres because it digs too far into the mids. This is a soulution that I probably do like.

Check out Martin's Presonance control in the tech section at the top of the boards If you haven't. That thing kicks ass if the amp likes it. If the amp doesn't like it.. well.. stupid amp!