Ersatz Verben - PT2399 pseudo reverb

culturejam · Post by **culturejam** » 28 Jan 2012, 01:48

For shits and giggles, I thought I'd see if I could do a poor-man's Clarinot with this thing. I threw a Bazz up front and upped the Delay time pot to 100K, but everything else was the same. No signal splitting, just ran the Bazz output straight into the 2399.

Surprisingly, it doesn't sound too bad. There are few oddities that I didn't expect (max delay time is quieter then medium, but here is also less feedback

), but it rather works. Of course, there's no cool pitch bend like on the Clari, but maybe I can use an LED in the Bazz and trick it into lighting up to power the LDR.

Anyway, this is a fun little base for experimentation. Big thanks again to allesz for coming up with the Crap-Fi, which inspired me to do the Ersatz.

mictester · Post by **mictester** » 28 Jan 2012, 03:04

culturejam wrote:
briggs wrote:It could probably make a really nice sounding bare bones chorus/flanger too if you used the LFO from Tim Escobedo's Wobbletron/Bigfoot FX Magnavibe (I've been using that recently ) to modulate the delay time....
The minimum delay time is a bit too long to make a good chorus or flanger. See frequencycentral's "Little Angel Chorus" for a neat trick to make a 2399 do the chorus thing.

I got amazing chorus with two PT2399s - with slightly offset delay times and wobbling the delay time a bit. I used two LFOs at slightly different speeds. There's slight reverb to the sound as well which just adds to the spacey chorus effect - it's quite ethereal!

rocklander · Post by **rocklander** » 28 Jan 2012, 11:30

had a quick crack (unverified) at a layout too (hope that's okay).. also 1590a.. and it's off the first schematic..

layout

: ersatz_v1-4-schem-layout1.0(c).jpg (66.31 KiB) Viewed 3276 times

pcb

: ersatz_v1-4-PCB 1.0.jpg (73.36 KiB) Viewed 3276 times

expresspcb file

ersatz-verben-pt2399-reverb-1590a.zip: (7.85 KiB) Downloaded 346 times

culturejam · Post by **culturejam** » 28 Jan 2012, 16:18

rocklander wrote:had a quick crack (unverified) at a layout too (hope that's okay)..

Of course! If I didn't want people to experiment, I would've kept the schematic to myself.

Nice work!

rocklander · Post by **rocklander** » 28 Jan 2012, 19:50

cheers for this.. I've been looking for a DIY pt2399 reverb I could get my teeth into.. this seems ideal.. any chance of some sound samples from someone who's already breadboarded it?

culturejam · Post by **culturejam** » 28 Jan 2012, 20:49

I linked a sound clip in the first post. Or were you looking for a clip of madbean's cool add-on?

rocklander · Post by **rocklander** » 28 Jan 2012, 20:56

culturejam wrote:I linked a sound clip in the first post. Or were you looking for a clip of madbean's cool add-on?

no no.. I was just being a blind numpty

mictester · Post by **mictester** » 28 Jan 2012, 23:10

This works remarkably well for such a minimalist circuit! There are some really great ideas here too.

Here's a quick Vero - it could (possibly) be made a bit smaller, but I hate standing resistors on end.

: OK!

allesz · Post by **allesz** » 29 Jan 2012, 23:44

Het Culturejam!
I just updated my crap-fi delay schematic: https://www.freestompboxes.org/viewtopic ... 41#p179541 it stay pretty simple but.... it seem to play wonderfully.
I think you could apply that simple mod to your reverb too, give it a look.

Dr Tony Balls · Post by **Dr Tony Balls** » 30 Jan 2012, 19:55

Here's a tighter vero layout for anyone interested. Unverified but it looks pretty damn right to me.

Seiche · Post by **Seiche** » 30 Jan 2012, 20:46

you guys are crazy, reminds me of

but where did that name come from? "Ersatz Verben"? wtf? "Substitute verbs"?
I'm always glad to help out with any german names anyone wants to give their circuit

culturejam · Post by **culturejam** » 30 Jan 2012, 21:10

Yeah, chose "ersatz" because it's used in English to me "replacement", usually in sort of a negative way. Kinda like "crappy replacement". And this circuit, while it sounds cool, doesn't really do a full-on reverb sound.

You see "ersatz" a lot in sci-fi from the 60s through 80s. That's where I learned the word.

And "verben" just because it sounds like it would be German.

Seiche · Post by **Seiche** » 30 Jan 2012, 21:26

culturejam wrote:Yeah, chose "ersatz" because it's used in English to me "replacement", usually in sort of a negative way. Kinda like "crappy replacement". And this circuit, while it sounds cool, doesn't really do a full-on reverb sound.

You see "ersatz" a lot in sci-fi from the 60s through 80s. That's where I learned the word.

And "verben" just because it sounds like it would be German.

yeah "Verben" actually means "verbs" (like adjectives, verbs, etc...), it's a noun and plural.
Reverb is "Hall"

Billig-Hall

culturejam · Post by **culturejam** » 30 Jan 2012, 21:57

Whoops. Maybe I'll rethink the name.

HEAD · Post by **HEAD** » 30 Jan 2012, 22:28

Sorry for being ot - but I totally love it how german loan words are used in the english language. Kaffeeklatschi is one of my alltime favourit!

Nearly every thursday I go out to a pub nearby my flat to play bingo with lots of english people who always join the game since its compered by an english guy.

culturejam · Post by **culturejam** » 30 Jan 2012, 23:16

My personal favorite is schadenfreude

Seiche · Post by **Seiche** » 30 Jan 2012, 23:32

there is a waterpark in South Padre Island, TX, that's called "Schlitterbahn". I thought that was pretty funny.

culturejam · Post by **culturejam** » 31 Jan 2012, 01:36

Not to derail the German-talken, but I just had an idea...

Okay, so what if LPF2 (op amp on pins 13 and 14) was set up with a LED between the input and output them... and then pump some of the input signal into the input (pin 13)? In theory, wouldn't that make the LED light up? And then couldn't that LED be used to wiggle a LDR off of the VCO to modulate delay time?

Dr Tony Balls · Post by **Dr Tony Balls** » 31 Jan 2012, 14:51

Seiche wrote:there is a waterpark in South Padre Island, TX, that's called "Schlitterbahn". I thought that was pretty funny.

The original one from that chain is the German-settled Texas town of New Braunfels!

earthtonesaudio · Post by **earthtonesaudio** » 31 Jan 2012, 15:37

culturejam wrote:Not to derail the German-talken, but I just had an idea...

Okay, so what if LPF2 (op amp on pins 13 and 14) was set up with a LED between the input and output them... and then pump some of the input signal into the input (pin 13)? In theory, wouldn't that make the LED light up? And then couldn't that LED be used to wiggle a LDR off of the VCO to modulate delay time?

I think that it would be unlikely to light the LED. Remember the op-amp is biased at 2.5V internally, and can only swing to +5V or 0V (ideally). Some LEDs will light at less than 2.5V but then the question is can the op-amp supply enough current at near the extremes of its voltage swing? That's doubtful.

If you take the LED outside the feedback loop (i.e. output of the op-amp -> resistor -> LED -> ground) it will work.
My German friend said "English is just a German dialect".