Foxhole Distortion? (DIY razor blade diode clipping)

[EBK]

I have absolutely no idea if this will pay out, but working on impractical projects keeps me (mostly) sane, and these trying times require even wackier distractions.

Teaser image (work in progress):

[iainpunk]

ooh, detector diodes!!
they have like a Vf of 0,2 right? and a relatively high ESR

i love it, i think i want to try it out myself, but with smaller pieces of steel and carbon due to size restraints of the candy cans i use.
no socket on the IC?? not afraid of frying her i see.

im out of the running until monday, when ill try the diode type out.

[anotherjim]

Stand well back! Eric's already spark eroded those razors and he hasn't even switched it on yet.

[duck_arse]

are you going to do carbon arcs w/ those pencils, as well? [there was someone showed a pic of gear w/ selenium rectifiers visible in recently, wonder where that was.]

[EBK]

are you going to do carbon arcs w/ those pencils, as well? [there was someone showed a pic of gear w/ selenium rectifiers visible in recently, wonder where that was.]

The pencil points will eventually rest on the oxidized portion of the blades as point contacts to complete the diodes.  I've also been told that phosphor bronze guitar string scraps might work in that role. I'll probably give it a try.

[willienillie]

are you going to do carbon arcs w/ those pencils, as well? [there was someone showed a pic of gear w/ selenium rectifiers visible in recently, wonder where that was.]

Selenium rectifiers as clippers?  The thought never occurred to me.  I don't think I have any, but I've trashed a few over the years, working on old gear.  What is their Vf like?

[duck_arse]

are you going to do carbon arcs w/ those pencils, as well? [there was someone showed a pic of gear w/ selenium rectifiers visible in recently, wonder where that was.]

Selenium rectifiers as clippers?  The thought never occurred to me.  I don't think I have any, but I've trashed a few over the years, working on old gear.  What is their Vf like?

there is a company, I don't know how I found their website, but they still custom manuf them in stacks and post specs. but I wasn't paying too much attention at the time. cehco or cougar, maybe.

[iainpunk]

are you going to do carbon arcs w/ those pencils, as well? [there was someone showed a pic of gear w/ selenium rectifiers visible in recently, wonder where that was.]

Selenium rectifiers as clippers?  The thought never occurred to me.  I don't think I have any, but I've trashed a few over the years, working on old gear.  What is their Vf like?

there is a company, I don't know how I found their website, but they still custom manuf them in stacks and post specs. but I wasn't paying too much attention at the time. cehco or cougar, maybe.

thsi website?
https://cougarelectronics.com/power-conversion-components/selenium-rectifier-suppressor/

[EBK]

Suppressors, eh? I got a couple 1N5657 TVS diodes in a random assortment recently.  Now I am wondering how they "sound".   
Next project, perhaps.  They look cool, anyway (admittedly not anywhere near as cool as selenium though):

[duck_arse]

just add some fins, Eric.

[thetragichero]

think i have some selenium diodes in a bridge configuration i replaced with a proper bridge.... i also have a ziplock full of trashed 2n3055s i planned to use as clipping diodes... maybe i can find an old enclosure to build a team fuzz in....

[EBK]

Feel free to show off any unusual clipping diodes in this thread.  Bonus points for building anything rediculously impractical for a guitar pedal.  Got a diode larger than a shoebox?  Let's see it and hear it!   

[iainpunk]

Feel free to show off any unusual clipping diodes in this thread.  Bonus points for building anything rediculously impractical for a guitar pedal.  Got a diode larger than a shoebox?  Let's see it and hear it!   

there is some sort of rectifier in my old car battery charger, looks like selenium with those bigass fins.

i also have a nice collection of high power resistor diodes (made to be put in parallel) in a very inconvenient package, the anode is just a thick lead, but the cathode is a piece of M5 thread...

[willienillie]

I've got a number of zener power diodes with the threaded stud.  Some of the smaller ones aren't too ridiculously huge for pedals, but I've never tried them for clipping.  As a side note, whatever the metal-can (RCA?) power rectifiers that Fender put in later silverface amps were, those sound quite good in a Tube Screamer.  I have some of the red bullet-shaped ones that Traynor used, maybe I should try them too.  I was digging around in a box of old bits last night, and found an NOS Raytheon 1N294, supposedly a 1N34A equivalent, it's red with a white band and looks cool as hell, but unfortunately I only have one.

[anotherjim]

A lot of those old battery chargers used centre tap secondary and only a pair of selenium diodes needed. Since they will have a common anode or cathode, you don't get a back to back pair *.
Doesn't stop you trying an asymmetric setup with another diode type and you do have an option to use the selenium as just one or both in parallel.
* You may be lucky and have a full-bridge. It can even be a full-bridge stack but only half used.

[vigilante397]

Anytime I see EBK started a thread I'm in. Looks great so far, looking forward to sound clips

[iainpunk]

A lot of those old battery chargers used centre tap secondary and only a pair of selenium diodes needed. Since they will have a common anode or cathode, you don't get a back to back pair *.
Doesn't stop you trying an asymmetric setup with another diode type and you do have an option to use the selenium as just one or both in parallel.
* You may be lucky and have a full-bridge. It can even be a full-bridge stack but only half used.

im not planning on opening the charger up tho, it belonged to my grandpa and i use it to power projects that run 12V and high power. but when applying reverse voltage to the leads, it starts conducting at 3-ish volts, ill put some terminals on an enclosure to use it as a single sided clipping diode, i think ill use a (pair of) Led for the other side.

Feel free to show off any unusual clipping diodes in this thread.  Bonus points for building anything rediculously impractical for a guitar pedal.  Got a diode larger than a shoebox?  Let's see it and hear it!   

is having to carry a 2Kg battery charger impractical enough for you, EBK?

[EBK]

I haven't posted a pic since the initial teaser.  This is all wired up and soldered, except for the pencil point probes.

[iainpunk]

what is the schematic of the distortion you have here??

[EBK]

what is the schematic of the distortion you have here??

It is 99% based on the MXR Distortion+.   It is also based off of the layout at tagboardeffects:
http://tagboardeffects.blogspot.com/2010/07/mxr-dist.html

I have added a switch to accommodate an attenuated diode lift mode to allow for a better evaluation of the effect of the diodes.
When the slide switch is up, it has a series trimpot instead of the parallel diodes (just an attenuator).  With the switch in the down position, the diodes are connected and have (at least until I start testing it and changing stuff) a saturation control ala Jack Orman.

If I haven't said it before, I have no idea if this will work or sound good.  It is a starting point for having fun.