Crowther - Prunes and Custard (schematic and Sabro vero inside)

[notnews]

[notnews]

Hey Guys..

My P&C crapped the bed after I gave it to a friend.. planning on just rebuilding it now that my building skills have matured a little bit and the parts count / parts rarity is low.

Does anyone here use a P&C?

I was thinking about the opamp and the diodes in this build. There are a thousand threads comparing the TL072 to other dual opamps like the NE5532, the OP2134... I guess my question is what role does the opamp and it's specific properties play in the sounds this circuit creates? The TL072 is a pretty decent audio-grade opamp. Would upgrading to a less noisy and more "hi-fi" Burr Brown opamp take away from the grit and gnarlyness of the sound? I know some of those BB's are prone to oscillation if you don't take that into account properly... could that be a positive thing in a circuit like this? Or just make things unlistenable?Would downgrading to a JRC or something like that make it sound even more crazy? maybe too crazy?

And same goes for the diodes... this diode configuration looks kind of unique to me, I don't think I've seen an arrangement like this in a pedal before. Would changing these diodes change the sound of the circuit? Or are these diodes more for polarity/protectional purposes? The 1N4148 clip really hard, right? The 1N914 has a slightly different forward voltage, but clips similarly. I did find this, thought I would throw this into the mix.. not sure how it would pragmatically apply to this circuit though:



Thanks guys. I loved this effect.. I'm super busy with work this week and won't have time to build it up until the weekend, so I figured I could maybe get a discussion going before then and have a jump-start on ideas by that time.

[2liveis2die]

Built one of these a few months ago. I tried a 072 and 5532. I found the 5532 to be grittier with the same innovative positions. As for the diodes i have no clue.

[KT]

I like the p&c a lot. Built two, one from sabro and one poodle pcb. Haven't tried different opamps or diodes yet

[Frank_NH]

"And same goes for the diodes... this diode configuration looks kind of unique to me, I don't think I've seen an arrangement like this in a pedal before. Would changing these diodes change the sound of the circuit? Or are these diodes more for polarity/protectional purposes? "

The diodes are configured as a "diode ladder,"  which is essentially a very smooth clipping circuit.  This replaces the usual two diodes to ground clipping, which tends to be more abrupt.

More information here:

http://dogstar.dantimax.dk/tubestuf/dzart-6.htm