Serendipity: more treble?

[Bucksears]

I wired/boxed up my Serendipity last night and REALLY like the sound of it. It gets VERY close to the sound I was getting out of my Jetter Gold (which is what I was hoping it would do); smooth, midrangey lead sounds, pinch harmonics happening a little too. It doesn't have as much gain on tap as the gold, but I'd like to swap out the 500k gain pot for a 1M and see if that will do it.
I think with some more gain and treble, it could (potentially) be a Mesa Mark I in a box. Total jazz-fusion/Santana leads going on.

And about the treble - I have to max out the voice and almost the tone control to get the bite I'd like. Almost all of the treble is at the end of the taper.
Is there any way to increase that in this circuit? I'd like a little more 'play' in the tone control - maybe should use a Lin pot instead of Log?

[madbean]

You can lower C4 to get more treble. I'd say 2n2 or 1n5.

Changing the drive pot to 1M might be okay, but you could end up with some oscillation. With 1M, your gain there is 1000! That's pretty intense. If you do end up doing that, I'd increase R9 to 10k or 15k. You could also increase R3 to 4k7 and lower C3 to 47n. That would balance out the increased value of the drive pot, still provide more gain without any oscillation and also preserve the frequency roll-off to the original design.

You could instead change D1-D3 to 1n34a. Swapping the diodes will lower the forward voltage and make the 2n7000's clip sooner, which will add a more gainey texture, on the other hand.

[Bucksears]

Thanks MB - I'll definitely look at lowering C4.

I already have 1N34A's in there right now (not the BAT41's); I thought about getting some of the BAT41's, but would that LESSEN the gain that I have now?
The BAT41's look more like 1N914's; do they sound any different than 1N34A's?

Also, other than changing the drive pot, is there any other way to increase gain just a smidge?

Thanks for your time,
Buck

[oldhousescott]

You definitely should use a linear pot instead of a log pot to spread out the treble control adjustment range more evenly.

To increase the gain a bit, you could try lowering R3 to 820r or even 680r, but don't go any lower, and note that the frequency rolloff character will change slightly with the voice control maxed out.