Hi
what is your power supply voltage? it runs at 18VDC?
What is the level of your input signal? you may try with 500mVpp or even 1Vpp.

Have you checked on C6's negative lug?
Can you swap Q2 with another J201?

Hi yes it is normal that not all the resistors are in the audio path. first you may want to check the power supply voltage in the circuit. Feed the pedal with a steady signal (sinewave is nice ), then check the signal path with something. Here your signal path is: C3 R7 Q2 C6 C8 R12 "GAIN"...

Sorry I forgot about C3, it's just a small buffer/filter on the +9V rail for the transistor power.
I'm used to always put a small cap on power lines.
You can use a ceramic, or anything cheap

Hi yes it could be interesting to have a multipurpose vactrol board, to hack existing circuits! Let me know if you need the tracks only to make small pcbs. Your vero seems ok. The idea with the LED resistor is that when the CV input is at minimum the LED should just be at the right current to be nea...

Nice!
I've drawn a quick perfboard layout with its schematic/parts: Let us know if it works

Hi it seems you've forgotten the LED and the LDR 8) Also the 1K resistor in the bottom right corner should be adjusted to suit the LED (but here it's connected to nothing). The LED should be connected to the emitter, by the way here's a standard pinout: https://protosupplies.com/wp-content/uploads/2...

One thing which is holding me down of digging deeper with this circuit, is that it is not true bypass, and i noticed that when bypassed, moving the expression pedal was chaing the dry sound... I guess this is because the audio is actually going through the filter pot, even when bypassed, so the exp...

Here is an example with the correct pin numbers, use an isolated jack socket:

Sorry still no edit: I've messed the pin numbers in my previous message. So to be clear here is what I take as standard wiring for an expression pedal: https://www.freestompboxes.org/download/file.php?id=33071&mode=view To correct myself: try to hook (Tip and RIng) + Sleeve or (Ring and Sleeve) ...

Have you disconnected the onboard pot when trying your TRS jack? This won't work if the expression pedal is in parallel with the pot, it should totaly replace the pot in circuit. If you have tried with an isolated socket you should be fine, the Sleeve is one end of the pot. So you can try to use the...

:roll: well maybe they have simply used a switched jack to connect the expression pedal in place of the pot like you tried before. You need an isolated stereo switched jack socket, so you can swap the Sleeve and Ring on the expression pedal to change the sweep direction. Remember the Tip is the curs...

No the vactrol and its driver are not shown. A vactrol is a LED + an light dependant resistor (more light=less resistance), so you have to know what resistance values you need, here it's around 50Kohm, so you'll add a limit resistor in parallel with the LDR to avoid huge values when in the dark (ie ...

Sorry no "edit".
By the way the pot1 is the expression pedal's pot which is more or less the standard value, 20K/25K it's ok.

Hello as the Frequency pot is wired as a variable resistor you could use a vactrol/LDR in parallel + a limit resistor (to limit the max resistance of the vactrol/LDR). Then with a TRS jack and a zener diode you send some voltage to your expression pedal (Ring), and the return (Tip) will go to a simp...

You can find several DI boxes which allow direct plug in the poweramp output, such as this one for example: http://www.radialeng.com/product/jdx-48 The Powersoak is an old power dissipator, simple resistor network, I still use it occasionaly to record straight from a Bassman head without speakers to...

If i wanted to use the main outputs (speakers), what kind of device should i use it with, to insert between the M100 and a mixer desk ? Something like a impedance matcher, does it exist for such a use ? Like a DI box, but to insert between a power amp and a mixer desk... A good old powersoak lets y...

Hi it seem the front DIN has an output for the mixer section, but could be used as insert (send return). If I am right you could have your mixer output at a reasonable level, on pin 4, but the signal will still be hot for your amp input (11mV). The other output on the back is a tape recorder connect...

Hi welcome here :thumbsup I'd say the simple way to reduce gain on the first stage is to put a second input resistor (say 100K for example) and switch between them. To me it is really useful when the fuzz is used with high gain pickups, they sound best with their input level attenuated with a 100K/1...

That's a good question.
Look if you target a large market, you'll need tons of gear, lots of amps, guitars, to test your design with many setups to satisfy more customers.
If you want to build some pedals for fun and your friends you may only need a good amp and a good guitar.

I use an old Sansamp, their early model.
It has enough tweaks to tailor your sound as you want, but yes it adds always its own color.
But I can't speak about the GT-2.