"Noise Ensemble" - simple PT2399 abuse!

[p_wats]

Hi there,
Paul based upon your last posts i drew a schematic, but i don´t know if they are like you had them in mind... So would you please be so kind an look over it?

ftp://epa-art.dyndns.org/Stuff/NE%20Schem.png

Ben

Whoa, Ben! Thanks for that. Word of warning though, I perfed my breadboarded version late last night (first mistake) and it isn't quite working properly (your schematic could still be correct though, as it might be my perf layout that's screwing up). I'll go over the breadboard and perf again tonight to see what's what.

Confession: this is my first time going from schematic to breadboard to perf, so don't get your hopes up!

[e45tg4t3]

No Problem Paul, there was a first time for all of us.. .. the only thing that cunfused me a little bit in your description was  the connection of R3+1Meg pot to Pin10.. I thought you may mean Pin 14 (Just because R3 is already Connected to pin 14)... So thank you for your kind words...

Ben

[glops]

I perfed and box one up tonight to send to a friend in Italy.  did it stock to the first schematic. hopefully, I will do mine tomorrow. may try some mods but really love this thing stock. 

[p_wats]

No Problem Paul, there was a first time for all of us.. .. the only thing that cunfused me a little bit in your description was  the connection of R3+1Meg pot to Pin10.. I thought you may mean Pin 14 (Just because R3 is already Connected to pin 14)... So thank you for your kind words...

Ben

Hey Ben, you are right, I was definitely counting the pins wrong on the right side (top to bottom instead...). Nice catch.

Also, I got my perf working last night with a few tweaks (you'll likely want the 1M pot on the other side of the 47k in Ben's schematic). I changed a few pot/resistor values along the way to get the optimal sweep for the various controls too.

I'll try to post a layout when I've got time to draw one up. It sounds crazy now! Very fun to dial in as much or as little repeat level as you want (as well as "dry" level). The 1M pot could also just as easily be replaced by a toggle that just breaks the connection to the 47K. You'd get a similar result. My advice would be to either breadboard or socket just about everything and adjust to taste.

All told though, this is a really fun pedal--5 knobs that are very sensitive to each other. I also find the fuzz more useful than the Clari(not)--I put a fuzz lift in mine and only use it clean, as it's too noisy otherwise.

The whole thing sounds like a being chased by an angry, farty ghost...in a good way.

[earthtonesaudio]

This is a fun little circuit. 

[Earthscum]

This is a fun little circuit. 

+100 to that... I've boarded this and tore it down 3 times now. Just too much fun getting nasty noise to the gigantic auditorium sounds... and the decay is awesome! If I box this up, I'm probably doing a couple of the previously mentioned mods, and a momentary button and max decay knob for it so I can use it to end a song live with that trailing off into silence!

[frequencycentral]

[earthtonesaudio]

One thing I found useful was to add an LED in series with the 47k* that injects the audio into pin 6.  Cathode to pin 6, this makes it so when the delay time is shorter, the LED resistance is lower, so the amount of modulation stays fairly constant throughout the delay range.

*You might need to tweak the value of this resistor depending on the output of pin 15 as well as the forward voltage of the LED.  I used some resistors to lower the gain of the input op-amp so I reduced that resistor value to something like 1k.

[clamup1]

this thing is funnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn. i have a fuzz, chorus, little echo from hell.  if it could be cleaned up it would be awsome. ill have to try the mods listed and see what happens. great circuit

[earthtonesaudio]

My tweaks:



100k is complete overkill for the delay time pot.  I really only use the first 10k of it.

[p_wats]

My tweaks:
100k is complete overkill for the delay time pot.  I really only use the first 10k of it.

Nice! What effect do the diodes have--are they helping to lessen the fuzz?

[earthtonesaudio]

Nice! What effect do the diodes have--are they helping to lessen the fuzz?

The input stage in Anchovie's schem has no feedback so its gain is very high.  In mine the gain is about 23 which is still fairly high but no longer fuzzy.  The diodes in the output section clip the signal and therefore add distortion, but the distortion from them is more gradual and "softer" than if I leave them out and let the op-amp clip.

[p_wats]

Nice! What effect do the diodes have--are they helping to lessen the fuzz?

The input stage in Anchovie's schem has no feedback so its gain is very high.  In mine the gain is about 23 which is still fairly high but no longer fuzzy.  The diodes in the output section clip the signal and therefore add distortion, but the distortion from them is more gradual and "softer" than if I leave them out and let the op-amp clip.

Oh, cool. Thanks for the breakdown! I'll have to see which I prefer more, as I'm enjoying the stock clipping so far. This circuit definitely has infinite posibilities!

[anchovie]

Alex, did you find that the filter caps that I left out became essential as soon as you stopped using the first opamp as a comparator? I was surprised that they added hiss and crackle in my original circuit.

[earthtonesaudio]

Alex, did you find that the filter caps that I left out became essential as soon as you stopped using the first opamp as a comparator? I was surprised that they added hiss and crackle in my original circuit.

I think I tried it first without one of those caps, but got better results with them in.  In particular I couldn't get anything useful (i.e. no audio) without the caps from pins 7 and 8 going to ground (or was it just the pin 8 cap...? I don't remember).  I did not try any substitute values in those spots, for what it's worth.  For the 9/10 and 11/12 caps I tried some different values but found 10n to be a good compromise between noise and bandwidth.

[Pigyboy]

Can you say 1590A?

[Perrow]

I just love these low part count circuits.

[duckpow]

I've put this together in a box yesterday It's an awful lot of fun. Did almost no change to the original design. Tried adding a feedback system... but it got way too fast way too wacky... and I love wacky 
Did add a cap to ground from input, to filter out some top end... It had a nasty crackle above 10khz
Will post pic when I have found my camera.

[earthtonesaudio]

I increased the gain and added some feedback:

[p_wats]

Thinking about finally boxing mine up this week (have the perfect Curious George tin for it). There's room for another small circuit in there though. What do you think would be a fitting compliment to this craziness?

Options I've got kicking around include:

compressors
tremolo (tremulus lune might have too many knobs, but the tiny tremolo would work)
fuzz (never a shortage of these...)
what (got a nurse quaky sitting unboxed)

Or other?