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DIY Stompboxes => Building your own stompbox => Topic started by: Oliver on April 01, 2004, 09:15:48 AM

Title: Distortion Problem (Clipping slightly gated)
Post by: Oliver on April 01, 2004, 09:15:48 AM
Hello,

after my Problem with a twoFaceOverdrive is history, i have the next
Mountain to cross....

I build a circuit out of the Tubescreamer to convert it to a Distortion with
hardclipping Diodes.

When Gain is cranked up the sound isnt the best, but it clipps hard.
With less Gain the Sound is gated a little bit like wrong biased.
I tried several diodetypes (1N4004 - nice Crunch/ 1N914 to smooth for my taste....)


It looks like the image as follows...:

(http://mitglied.lycos.de/surftone/gitarre/effekte/ts-808_hardclipp.JPG)

can anybody help to get that circuit working like a real distortion like the DS-1 or MXR Dist+?

The Background is, that i modified my TS to switch between Overdrive and Distortion (the Switch cuts the Diodes out of the FeedbackLoop and adds two as seen in the Image before the LevelPot...

Thanx for Suggestions


cu
Oliver
Title: Distortion Problem (Clipping slightly gated)
Post by: will on April 01, 2004, 04:42:23 PM
Hi Oliver,

Your volume control on the end of the circuit I believe should be connected to ground not your voltage reference at this point. I suspect the output is connected to ground, if so your circuit is creating a lot of noise (voltage drop accross the volume pot), also causing one of the diodes to clip 1/2 of your signal as the doides are connected to ground but the volume control VR is trying to pull the circuit to approx 4.5 volts.

I hope that helps. Good luck!

Regards,
Will
Title: Distortion Problem (Clipping slightly gated)
Post by: RDV on April 01, 2004, 04:47:07 PM
I'd also suggest a small value cap(maybe .001uF or so) to ground right after the diodes and before the volume pot to smooth out your distortion a bit.

Regards

RDV
Title: Distortion Problem (Clipping slightly gated)
Post by: aron on April 01, 2004, 06:48:40 PM
Yep, the following:

Ground your volume control instead of to VR
Verify that VR is 1/2 V+
Verify that your input pins on the op amp are VR
Title: Distortion Problem (Clipping slightly gated)
Post by: Oliver on April 02, 2004, 07:12:05 AM
Hi and Thanxx!!

that sounds good -

i'll try that Mods

 :D   :D  :D

ciao
Oliver
Title: Distortion Problem (Clipping slightly gated)
Post by: Oliver on April 03, 2004, 05:53:52 AM
HI - the Distortion works !
i grounded the Level Pot, that helped !!

ThanXXXXXXXXX

Oliver