DIEFET: A French Diezel VH4 Jfet Simulation

[gtudoran]

thank you a lot for your tips, i will do that tomorow morning and i will keep you informed. i will replace the tranzistors and IC too just to have a clear ground to start from... hope i didn't trash them all.

best regards,
Gabriel Tudoran
Analog Sound

[Ripthorn]

Removing the cap and resistor as mentioned by caspercody fixes the volume problem and don't connect the jumpers.  The v.1.21 is pretty darned awesome if you ask me.  I have made a couple and this is my favorite heavy distortion.

[gtudoran]

The only substitution i've made is the diodes, i've used 1n914... does it make a big difference?

Thank you in advance.

[Ripthorn]

Did you replace the 1N4004 with a 1N914?  The 1N400x series are rectifier diodes with a .7V forward drop.  Changing that might have an effect.

[gtudoran]

Battery voltage:6.55v (i know is gone but was the only that i have at this moment)

       D                S                 G
q1:3.4             3.4                4.2
q2:3.8             3.8                4.5
q3:3.4             3.4                4.1
q4:5                5                   5.77
q5:5.77           5.77               6.55

If i touch the input of C21 i have signale from there to the end and the controls are acting normal.
The AJ4 it seems that it don't do nothing... i have the same voltage reading at any position (i will try to replace it)
Forgot to tell you: for gain pot i used one of 200k, and for volume pot i used one of 1M (but i don't think that is a problem as long as i got the signal passed from C21 to output.

Still no sound, all jumpers cut, except the ones from tone stack and the one under IC socket.
Removed the  R25 and C32 and relace them with a jumper.
I'm running out of soultions :|

Best regards,
Gabriel Tudoran
Analog Sound

[gtudoran]

I think the layout is a little crappy... at least for version 1.21'.... in the picture that come with the schematic the FETs have different orientation... at least for Q5 and has a jumper (not reffering to j2-j5)... i will try to get a closer look.

Best regards,
Gabriel Tudoran
Analog Sound

[caspercody]

I do not remember if I rotated the Jets or not.

But the jumpers AJ2-AJ4 I have no idea why the are there. They seem to ground out the drains of the Jets if you install them.

But I know that pcb for v1.21 works. And the only thing I did different is leave out the jumpers, and remove the resistor and cap (but like I mentioned I do not remember if I had to rotate the Jfets). Look at the pin layout for the Jfets you are using,and compare them to the pcb layout.

Or make a audio probe, and dig into the build. I can not counthow many times I needed to use a audio probe.

[gtudoran]

Done... for version 1.21 rotate the FETs with 180 deg.

Best regards,
Gabriel Tudoran
Analog Sound

[Ripthorn]

I admit that I didn't use the layout posted.  I used one made by garrett and it has worked both times quite well.

[caspercody]

Good to hear you got it to work.

[gtudoran]

Thank you for all your help with this one ... i was in a dead end. Anyway is a good sounding pedal... not bad at all, in fact i found it a little more meaner then Dr. Boogie.

Best regards,
Gabriel Tudoran
Analog Sound

[gtudoran]

Hi guys, this is my recording with Diesel Fet Simulator:

http://analog-sound.com/forum/index.php?action=dlattach;topic=48.0;attach=73

Best regards,
Gabriel Tudoran
Analog Sound

[KH602]

i have a 12V 2A power supply lying round that could be used, will it work fine with the diefet 1.21

or will it blow any components such as the diode on the 12V input?

[kupervaser]

I built mine with the 18 volts voltage doubler like many others on the forum.

[KH602]

yea i read about that. am only asking just cause the supplys new that i have dug out. will my 12V 2A supply blow the 1n4004 diode?

every diefet schematic i look at the diode seems to change from 1n4148 - 1n4001 - 1n4004

[caspercody]

The 12 volts is less than the voltage others have used on this poject, so that part will not hurt the circuit.

The 2 amps portion, the circuit will draw what current it only needs. You are not actually pushing 2 amps into the circuit.

[KH602]

anyone have the eagle layouts for the diefet 1.21 ? really could do with them

[MuNdrY]

Hello there: i've build the Diefet with my own layout based on the 1.2 version.

i've got some problems:

-a massive drop of volume
-presence don't do anything
-tonestack work bad : if i lower bass and mid the pedal become mute.

for the volume i've removed R25 (220K) and lowed R19 (120K) to 22K and now the volume is pretty good, i have to remove C32 (100pF) too to raise more the volume as i read here (thanks Caspercody).

for the presence i've changed the pot value from 25K to 100K, the action now is a little better.

for the tonestack i've modified the mid pot wiring like the Dr.boogie: C24 (1nF) removed, C22 (22nF) to mid pot central, pin 1 of bass and pin 3 of mid connected togeher, now the tonestack work good but i want to know: is this an uncorrected schematic bug or i'm the one with this problem?

p.s. sorry for my bad english

[MuNdrY]

UP

[tuckster]

Does anyone got the vero layout for version >1.21 ? I swear i saw it this morning but I can't find it now.......