DIEFET: A French Diezel VH4 Jfet Simulation

[Ripthorn]

you have 3 controls to adjust the bass on this pedal: BASS / DEEP / And an extra control "CUT" who decrease the bass BEFORE the tonestack and the DEEP control.

I may be crazy, but I don't see any kind of "CUT" control on the schematic or layout.  Is this something built in or am I just not looking in the right place?

[ech0es]

to have the "cut control" you have to use a trimpot or a potentiometer of 500k instead of the 330k resistor.
This resistor with the 47nf , just after the third fet make a highpass filter with a cut frequency at 10Hz.
You can change this value from 5Hz to 340Hz with the new pot from 10k to 500k.

[Ripthorn]

I was wondering what that note in French meant...  Thanks!

[ech0es]

for the 1.21 version, it's the 3,3n cap and the 100k resistor after the third jfet

[audioguy]

I don't know if it's smaller, but here is my build (it wasn't finished in the picture yet but it's finished and working now):


Stuff got a bit squashed around the C6 and C8 cap but it all fits in the end. Should have moved C12 a bit to the left and up as well. If you want the eagle files PM me.

ps. The layout is based on version 1.1 and not 1.21

I just finished this build and wasnt able to get anything but oscillation. BUT I noticed that one of the trim pots is 500k AFTER building the entire thing... I dont have any 500k trimmers, so I'll have to put the trouble shooting on hold.

Thanks for the layout... I'll keep working on it.

[gkoerselman]

I just finished this build and wasnt able to get anything but oscillation. BUT I noticed that one of the trim pots is 500k AFTER building the entire thing... I dont have any 500k trimmers, so I'll have to put the trouble shooting on hold.

Thanks for the layout... I'll keep working on it.

When I build mine initially I messed up and put in a 100k trim pot. Couldn't get the voltage to bias at 6V, but I got sound.

[ech0es]

mine:

[audioguy]

I just finished this build and wasnt able to get anything but oscillation. BUT I noticed that one of the trim pots is 500k AFTER building the entire thing... I dont have any 500k trimmers, so I'll have to put the trouble shooting on hold.

Thanks for the layout... I'll keep working on it.

When I build mine initially I messed up and put in a 100k trim pot. Couldn't get the voltage to bias at 6V, but I got sound.

I was looking at the other layouts- they all have 1 more trim pot than your layout??

[Ripthorn]

I was looking at the other layouts- they all have 1 more trim pot than your layout??

From what I see, it looks like the extra trimpot is actually the "cut" control.  I could be wrong, however.

[audioguy]

hmmm...

[gkoerselman]

The original schematic lists a 330k resistor with a trim pot replacement as an option (R8 in Echo's layout, wired as variable resistor), yes the 'cut' control.

Version 1.21 has a 100k resistor in there instead. In my schematic this would be R12.

Have you audio probed your build yet? If you would like me to measure points in my build, PM me...

ps. Debugging is always madly frustrating, but it's where you learn the most about this stuff.

[Ripthorn]

I just finished this build using Gerrit's layout.  I made the version 1.21 mods and left out the presence pot, and this thing is great.  My one observation as of right now is that the gain control is mildly useless.  If I were to build this thing again, I would probably just put in a fixed resistor and call it good.  I mean, this is meant to be high gain, so why try to tone it down (especially when I have other pedals that will do that for me).  Short and long is I love it.  The deep control allows you to get that really bottom heavy metal sound.  Great stuff.

[ech0es]

i don't agree with the fact that the gain control is useless: If you change the setting you can find some level of various crunch, who change with the dynamic of your picking.

Soft Pick -> Slight crunch
Hard pick -> Heavy crunch

It's a very dynamic distortion pedal!

[omarvolta]

I just finished V1.21. There wasn't enough volume for some reason but bypassing the 220k/100pf before the output did the trick and now there's enough for a passive boost. I'm not sure if the drive/gain control is behaving as it should. When fully CCW there is some drive but almost no volume. Is that how it should work?

[Ripthorn]

When I turn the gain CCW, I get a volume drop, but still a decent amount.  The thing I notice is that the distortion gets fizzy and not terribly desirable.  But that is just mine.  Plus, I always just crank the gain, I have other better crunch/medium distortion pedals.

[ech0es]

Share your settings!

My Matthew bellamy/Wes Borland settings:

GAIN: 2h30
VOL: 4h30
DEEP: 10h30
BASS: 9h30
MIDDLE: 3h
TREBLE: 3h
PRESENCE: 3h30

Use the volume pot of your guitar to experiment several level of crunch (slight crunch-->Fat ass crunch)

[ollie]

Hey,

can anyone help me, i want to buy one of these pcbS but can't find anywhere on the site to do it

[DSV]

Here: http://www.techniguitare.com/forum/viewtopic.php?t=8209

Send a mail to shaddo, he'll give you all the info.

[ollie]

Perfect, thank you 

[kupervaser]

Is there a layout of Diefet version 1.21?
Can someone post it here?

And echoes, can i have some pictures of the pedal you posted earlier from the inside. I want to see how i can manage to fit it in BB enclosure.

Thanx in advance,
Jeff