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Re: Friedman Dirty Shirley

PostPosted: 12 Nov 2017, 05:37
by Manfred
Branimir wrote:I understand, but that's with DC current, what about RF signal ? Can you sweep it with pink noise and voltage dependant 0,5 to 1V?

There must be some measurable difference between the 1N4148 and the Schottky

Exucuse my poor technical English!


The BAV99 contains two high speed switching diodes not Schottkys.
The diode capacitances of 1.5 Pikofarads for the BAV99 and 4 Pikofarads for the 1N4148,
having no influence on audio frequency range.

Re: Friedman - Dirty Shirley

PostPosted: 17 Nov 2017, 08:49
by HamishR
So I can use 1N4148s and I shouldn't be able to hear any difference from BAV99s. right? Thanks for documenting this.

Re: Friedman - Dirty Shirley

PostPosted: 19 Nov 2017, 00:09
by roseblood11
Has anybody built a version with the parts values of the be-od and the controls of the dirty shirley?

Maybe I'll try that - my pcb arrived today :D

Re: Friedman - Dirty Shirley

PostPosted: 20 Nov 2017, 03:02
by bugg
roseblood11 wrote:Has anybody built a version with the parts values of the be-od and the controls of the dirty shirley?

Maybe I'll try that - my pcb arrived today :D


The only significant component value difference (aside from an the new active midrange control) is the 27K (10K in the BEOD) resistor between the second clipping stage and the presence control...

I'd be interested to hear how it compares if you try it.

Re: Friedman - Dirty Shirley

PostPosted: 20 Nov 2017, 10:41
by Optical
bugg wrote:
roseblood11 wrote:Has anybody built a version with the parts values of the be-od and the controls of the dirty shirley?

Maybe I'll try that - my pcb arrived today :D


The only significant component value difference (aside from an the new active midrange control) is the 27K (10K in the BEOD) resistor between the second clipping stage and the presence control...

I'd be interested to hear how it compares if you try it.


I believe that 10k/27k resistor just sets the gain of that stage. Setting the internal trimpot of the BEOD to a low setting would achieve much the same thing...
Breaking out that trimpot and adding the mid control would produce a pedal capable of all the BEOD + DS tones

Re: Friedman - Dirty Shirley

PostPosted: 20 Nov 2017, 17:06
by Frabbio
Single sided layout for Dirty Shirley+Friedman BeOd in a box, this layout has the best of both worlds, there are 7 pcb mounted pots so you can build a BeOD with a mid control, or a DS with a tight knob, as said before the only notable difference is R16 in my schematic (10k for BEOD, 27k for DS).

I used through hole ICs this time, but i kept the smd diodes (BAV99). If somebody is interested i can post the same layout with normal diodes.
Board dimensions are 115x40mm, it should fit in a hammond bb enclosure.
Layout still unverified but it should work.

If you build it please report if everything is working as intended.

Good DIY!

Re: Friedman - Dirty Shirley

PostPosted: 21 Nov 2017, 18:24
by efe
Great idea :applause: I was planning to buy 2 PCBs and put them in a box but this is what i need