Wanna build reverb without a bulky Belton brick? Bluff Chill Ectoverb got you covered. This one is using two PT2399 ICs in series to achieve a quite murky, spacey and lo-fi reverb. Schematic and more info HERE.
Wanna build reverb without a bulky Belton brick? Bluff Chill Ectoverb got you covered. This one is using two PT2399 ICs in series to achieve a quite murky, spacey and lo-fi reverb. Schematic and more info HERE.
super cool design! will have to give this one a try. for the optional mod board connection, would that be the input out output of the mod board - also where would the other connection go?
ReplyDeleteModulation/LFO circuits usually only have one audio out connection. Shat connection should be connected to pin 6 of IC2.
DeleteI'm not too familiarr with the modulation boards out there but I would suggest to check out the Tagboard Fx forum. I'm sure there are several types of there.
The one I'm familiar with sits in the 'time' section of a PT2399 where time1 hits the LDR and Time2/3 are on the switch.. Nothow that works with just one input here.
DeleteOhhh very nice … I’ll start to building . :) . I look at the schematic and I see that the ics terminals are confused. they probably put it this way to get the schematic out easily. anyway, what is the leftover mod? Logically from what I see it works and without it just what is it?
ReplyDeleteYes, the modulation daughterboard is entirely optional. It will work as a regular reverb circuit without modulation.
DeleteIt works. Verified. It’s reverberating but with a single slap-back delay when the mix is cranked clockwise. With the Mix back it’s less noticeable. It’s a nice simple reverb. Thanks!
ReplyDeleteUpdate. Fb-b doesn’t seem to work. I’ll have to study the scrmatic. Dark and lo-fi. Certainly not a spring tank. Think that’s the point though. So, partially verified.
ReplyDeleteI'm super interested in this one as my first modulation build... I started making the board last night but I will hang back just in case there's any update...
ReplyDeleteOkay so I think I had a bad 2399. First one ever somehow. But basically it seems that “feedback-a” is a longer delay and “feedback-b” is a shorter delay. The signal is split early on in the circuit so you have a blend between a flat input dry tone and an effected tone which is a bit darker sounding. You have the option of adding a mod board which I’m sure effects only the wet part of the circuit. It’s a decent Lofi effect but it’s not the best reverb possible. Maybe the best possible without a Belton brick. I also noticed a slight volume drop as you mix in more reverb. I might try some different fets in Q1 which I think must be for recovery solely. I may even futz with the drain resistor. Probably won’t do much. Nice layout as usual Fuzzhead. Thanks
ReplyDeleteThanks for verifying. Yes, I think you are right, it won't be the best reverb around when comparing it to brick or Spin reverbs but it is possible the best you can get when using two PT2399s....
DeleteFor fursther tweaking and longer delay times, you can experiment with the 2,2k and 10k resistors that connects to pin 6 of each IC. Try replacing them with pots up to 50k. However, you'll need to ad a at least a 1k limiting resistor to ground connwcting one of the outer lugs otherwise the ICs might latch up.
For Q1, I doubt you'll get more output out of it since it is a unity J FET buffer for the clean signal only.
You mi
I built this and it was cool. I added a LFO daughterboard but be aware that pin 6 of the PT2355 can't go over 2.5v without some nasty sounds. So I added a small voltage divider with a 1n4001 after it to keep the voltages under 2.5 v, now it adds some interesting motion, with a volume swell after the initial attack.. very ambient.. very fun
ReplyDeleteAnother Verification for you. And a little demo/knob twiddly viddly:
ReplyDeletehttps://youtu.be/qN719PnBqek
Works as expected without a belton. Pretty nice and spooky sounding. My main gripe is that the dry signal sits a little below unity when the reverb is mixed in more than about 20%. Not the worst but definately noticable. Its fairly hissy but can be controlled with the right combination of caps over the 2399's pins 15&16. Iirc i went with 100pf top and 220pf bottom. 1nf was way too high and just killed the feedback. I also swapped the 10k from pin 6 on the second chip for a 2.2k in series with a 20k pot. This lets you make the repeats a little faster or slower than standard giving it a bit more 'space'. I made a daughterboard for the modulation based on the modulation section from the pitch pirate. (Schem and layout if anybody wants it.)
Anyway, its not half bad, fun and can get pretty moody and trippy, but its not going to replace a good amp reverb or something with a belton.
Hi! i felt the same about hiss and dry signal when mixed. I would like the layout for the modulation section, if possible! the one i used doesn't seem to make an huge difference. also i didn't get the 1nf part. Did you change both 1nf caps? to what value? thanks in advance
DeleteSorry i didnt explain that too well.
DeleteIt was the 50pf caps i changed. In the notes it says you can go up to 1nf to remove the hiss, but that just killed the feedback entirely. So i changed the top 50pf to 100pf and the bottom 50pf to 220pf. Which helped reduce some of the hiss without affecting the repeats too much.
Ill post the layout for the modulation as soon as im back with my notepad. its just a hand drawn layout and its a bit janky but it works.
really enjoying this pedal with your suggestions but struggling with modulation (which i think it would make it even cooler). i tried a modulation board from sabrotone but only did something when playing directly with depth pot! now i was trying the mod board from de profundis delay but can't figure out where to connect the second leg of the ldr (the one that in a normal delay would connect to lug 1 of time pot). can someone help me with this mod board?
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