Karltana Fuzz (Karl Fuzz + Katana Boost)

[Mr. Lime]

I always liked the demo videos of the Lovepedal Karl Fuzz and the Katana Boost sounded not bad either to me.

Why not putting both together in one pedal with an additional tone control and a 18V charge pump?
Here's my try on it.
Basically it's just a Katana Boost input stage, a interstage divider to control the amount of Fuzz, than a BMP tone stack followed by a Katana output/recovery stage.

There is one switch to switch in a bypass cap for each gain stage and one switch to lift the non-selective frequency tripler or lift the tone stack. In the middle position are both lifted to get the boost alone.
That's the idea so far but is there anything that looks odd or could be better?

I would be glad to get some suggestions..
Thanks a lot!

[nocentelli]

I just tried a simplified version of this out on the breadboard. JFET and tripler section only, and only running on 9volts. Sounds fun, normal fuzz up to halfway on the fuzz pot, beyond that the upper octave comes in and at maximum fuzz and on the neck pick-up with tone rolled down, there is a lovely lead fuzz tone. High fuzz settings with chords make it sound more like a poorly superfuzz, lots of heavy intermodulation distortion like the transistors are dying a painful death (I think the original Karl fuzz/Trippler sound like this, though).

I think you need another coupling cap after the fuzz pot (i.e from lug2), and the 500k resistor that is in parallel with the 390p cap from Mr Escobedo's original, and maybe another coupling cap after the clipping diodes and before the tonestack.

[Mr. Lime]

Why should be there another cap in series with C1?
C1 as coupling cap already blocks the DC..

I also don't see the use of a cap between C5 and the tone stack, but I may be wrong..

I decided to move the Gain/Fuzz control behind the first gain stage because everyone's got the Fuzz control as it is in the guitar, it's just the volume control.
Low gain settings on the Karl Fuzz sound really good and should work with this circuit as well.

Is there a need for a buffer infront of the tone stack?

[nocentelli]

Why should be there another cap in series with C1?
C1 as coupling cap already blocks the DC.

You have the bases of the npn+pnp transistors of the Karl/tripper circuit connected to ground via the gain pot: As you vary the gain, the dc resistance to ground will vary from 100k to zero k, altering the bias.

I am not certain that another cap after the clippers is strictly necessary, but usually when you see clippers to ground, they are isolated from the preceding and following stages with a cap either side.

[duck_arse]

I'm pretty sure nocentelli is also just about to say that the second fet needs a gate resistor to ground, to bias it when the switch points to the diodes. perhaps the bias resistor and a blocking cap, between the tone pot and the gate. and drain resistors in series with the trims, to prevent killing fets.

[Mr. Lime]

Alright, thanks for the explanation!

I missed that the ground connection is broken which is needed for biasing the FET..
Drain R with 1k and the new caps with 220n are fine?

Here's the corrected schematic:

[duck_arse]

looks good from where I'm sitting.

[Mr. Lime]

Now here's the Layout:

Component numbers don't match the schematic..
I know there are standing resistors and the diode pair share the holes but it should work anyway.  

[duck_arse]

well, your left-hand bottom Q, ?Q1? is missing its source resistor, but I can't tell you what part # it should be. (you will need to make schem and layout numbers match .....)