DIEFET: A French Diezel VH4 Jfet Simulation

[Ripthorn]

Tonestacks always reduce the volume a lot, that's just the way they are.  I always have mine cranked, but don't notice any change to the tone (it shouldn't, because the volume pot is just a voltage divider just before the output).  If you really want more volume, you can build a simple booster after it to boost the level.

[caspercody]

What one would be a good clean booster?

[kupervaser]

I disagree you need a booster.

Listen to my sample:
http://soundclick.com/share?songid=7627711

Just get hte tonestackout and start putting it component by component and listening with an audioprobe.

[Ripthorn]

Taking out the tonestack does the same thing to the volume as adding a booster, it's just that using a booster would allow you to still use the tone shaping tools of the tonestack while getting more volume.  If you want to have the tone controls, use a booster, if you don't want to use the tone controls, bypass the tonestack.  Two totally different ways to get more volume.

[kupervaser]

What I meant, was get the tone stack out, and start puttin it back in component by component and listen where it goes wrong. This design had to work, it sure does when i built it.

[caspercody]

I took out the tone stack, and it has a boost to it. The presence control did not seem to do anything after I took out the tone stack, so I disconnected this also. I added a baxendall tone stack (I have this in a separate box so I can add it easily to any pedal) and no boost in the signal. I have the volume cranked on the pedal, and it is just as loud (or less) when I bypass the pedal. So, this tells me there is nothing wrong with the original tone stack, that this pedal just gets sucked down in output when you add a tonestack to it.

Maybe more voltage? I am using a 9v battery.

Does the presence control need the tone stack? I would like to get this to work, but did not seem to do anything once I removed the tone stack. I am not to up on how the presence control works.

Right now I am happy with that it works, and is very quite for a high gain pedal. Will keep on working with the tone stack later, but could anyone help on answers to questions above.

Thanks

[kupervaser]

Man, I have no idea, i built mine with a voltage doubler. Maybe you could try this. Good luck

[caspercody]

Do you happen to have a schematic for a good voltage doubler?

I will give that a try.

[Ripthorn]

If you use a charge pump, they show you how to do it in the data sheet, or you can check out the +17V, +25V, etc. from One Battery page at Geofex.  It uses a MAX1044 chip or similar and 2 caps and 2 diodes.  Just make sure your components are rated for the voltage.

[kupervaser]

I made this one:



But this one has been used by someone else and it works fine:
http://www.circuitsonline.net/circuits/view/138

Good luck

[caspercody]

Wow, I had none now I have three to choose from. Thanks!!!!

[caspercody]

Finally!!!

I removed both R25, and C32 and works. I know I read this in here before, but I thought I only read to remove only R25. I did not remove C32 before.

Thanks for all your help on this!!

[kupervaser]

Did you put jumpers instead? Have you also built the doubler?

[caspercody]

I did not install the jumpers (J2-J5). I did have them installed, and the pedal did not work. I cut the jumpers one at a time, and the pedal started to work once all of them were cut.

I have a 12vdc power supply and hooked this up, but no big difference. So, I am still running this on 9v battery.

But once I took out the resistor, and cap mentioned by others here the output increased enough.

[ech0es]

Hi guys, i've planned to sell mine (see photos on this topic) , it has a voltage doubler in it so you plug 9v and the pedal works on 18v (max1044 inside), it gives more headroom.







Contact me by pm if interested.

[Kon_fución]

If I'm feeding it with an 18v power supply, is the Bias suppose to be 6v and the Reference voltage 9v?

[gtudoran]

Hello guys, did anybody did the 1.21 version... i finished mine and ... it dose not work... i have a lot of hummm when i touch the input the hum is gone... no sound passyng by.

Thoes jumpers need to be conected? When jumer j5 was connected to ground Q5 was hot as hell, i've disconected the j5 and Q5 was normal... could you give me a little kick start for debugging?

Best regards,
Gabriel Tudoran
Analog Sound

[caspercody]

Do not connect the jumpers!

Only the ones shown on the pcb.

[gtudoran]

wold be possible that all tranzistors and IC gone dead from that?

I've disconected the jumpers (besides the one from tone stack and the one under IC... and still no sound.

Best regards,
Gabriel Tudoran
Analog Sound

[caspercody]

Looked at the pdf file again, do not connect J2 - J5 jumpers. I asked this question when I built this, and never got an answer. So I hooked up jumpers to each one, and no sound. I started cutting the jumpers one by one and no sound till all where cut. Not sure what the jumpers do.

Also, when I got this to work there was barely any sound till the volume was cranked. And even than it was barely unity gain. Remove R25, and I think C32 fixed that problem (it is somewhere in this tread).