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If I add a buffer in front the problem is solved.
If I only tested that before butchering the board and installed sockets and destroyed a good transistor

Does not anyone else experience this?
If I dont plug anything in the input jack and turn up gain and volume in boost mode, it self oscillate like CRAZY.

btw. It sounds freaking AMAZING!

I'm having some problems with self oscillating/squeal in the boost mode.
This happens when volume and gain is at about 12 o'clock and more (only in Boost Mode)
I have matched the transistors and I use 33K for the bias resistors to get about 4.4 Volt at all testpoints.

Have anyone else experienced this?

I tested it outside the box and thought it had to do with all the long wires on the test rig.
I boxed it up and got the same result.

I tested all resistors and caps before I soldered them in. Normal mode works like it should.

EDIT:
I have now desoldered the transistors and bias resistors and soldered in sockets.
I got the j201's from Tayda.

EDIT2:
I got my TweedyBird up and running with J201's from the same Tayda batch and it's working fine.
Can someone with a black '65 clone crank the volme and gain pot in Boost mode and report back ?
I use a Jazzmaster with 1MEG pots btw.

EDIT3: Installed shielded cable from input jack to 3pdt switch and from 3pdt switch to input at board.
Did not help much.

Nice build! I love the Small Clone and Stone, got them both on my board.

OK, thanks.
I managed to match six JFETs for the Tweed and four for the black
Now I just have to build them!

Thanks Jon.
I swapped R3 and R4 and turned the JFET 180 degrees.
Now I get more reasonable results

Does it matter that I subbed C1 470uF with 100uF?

I have never used a breadboard, but now I have to
I'm building the Tweedy Bird that I got from Chi_Boy, http://home.comcast.net/~gprause/PCB/Tweedy_V2.0_Build_Doc.pdf

I tried to transfer this schematic to breadboard:

I have subbed C1 470 uF with 100 uF, is that a problem?

This is how my breadboard looks now.
Can someone please check it and tell me if it's correct?
I know there are some unnecessary jumpers...




I get about 1.5 V on the J201's I have tested. (supply voltage is 9.3V)
To get about 4.6 volts i have to use a 1K2 resistor in R2.

Thanks! I'm going to rock the ToneBender on rehearsal today.

King of Klones
I call it Son Of A King, but as you can see i messed up and called it sun of a king
I did not realize that before I boxed it up.
The hi/low gain is just a ~160k resistor on the gain pot so the pot (250K) becomes 100K


Pastyface / Tonebender Vox MKIII with OC75 transistors and a roadrage
I should have called this MindBender because I had to bend my mind to figure out the positive ground stuff.
It's easy but confusing for a noob like me
I jumpered R10 to get above unity gain, thanks KCTigerChie
http://www.madbeanpedals.com/forum/index.php?topic=9564.0

Thanks, that fixed it!

Now R7 is connected to the trim pot, not to ground 
The trim pot is now working and I get about unity gain when everything is on MAX.
Is it supposed to be like this or, do I have to use a lager Volume pot to get more output?

What change does the cap sub I did make? (I have subbed C3 6.4uF with 4.7uf )

I'm pretty sure they are oriented the right way. If I flip them around i get less gain.
I'm getting about 4.5 volt on q1 and q2 but 72mV on q3.
Hmm, is R7 connected to the right hole? R7 is next to R12

Edit. It seems like I have connected r7 to ground instead of connecting it to the trim pot
What is that ground hole for anyway? Is it a trap

I'm building a Pastyface with Vox Tonebender MKIII specs.
The output with everything om max is below unity.
I have subbed C3 6.4uF with 4.7uf and i use a 500k trimpot.
I hear no difference when turning the trimpot, but when i test the trimpot with a multimeter it changes value from 0 to about 500k
I use OC75 transistors Q1 and Q2 is 70hfe Q3 is 100hfe
I measured every component before soldering it.
Here is a pic of the component side of the PCB.

No you can't.
You could probably convert the circuit to positive ground so you can use the PNP transistors, but If  it was me I would just get some NPN transistors, and use the PNP's for other projects.

Thanks!

How much do you have in stock of the Snarkdoodle, EgoDriver and Pepperspray?
I'm not sure if I should wait for the sale or not