BBD reverb

[kokoon]

 

so - as i promised - the sample. i recorded it on 2 channels (wet and dry signals separated) so you can turn either one on/off as you wish. if you just want to listen to what it sounds like then go with the mono mp3.

the original .wav file (stereo - wet/dry separated)

mono .mp3 (50/50 mixed wet/dry)

stereo .mp3 (stereo - wet/dry separated)

 

it's a fairly long twiddling session, for the first ~10 minutes just the R-8 playing an 808 snare and an 808 rimshot, then i switch to a bit of poly-800 for last few minutes.

 

as you'll hear, effects range from simple delay, echo, to (quasi)reverbs, flanger, chorus...

 

ANALOG!!!!!

 

let me know what you think. oh! also check out the frontpanel i designed for it and tell me what you think. could you use the unit?

[Guest analogue wings]

Nice work!

 

Analogue delay is the one effect I couldn't live without.

 

What chips did you use, and are they still made?

[kokoon]

as you can see on the first photo, Panasonic MN3011 is the main actor here. it's actually a 6-tapped BBD chip. the special thing about it is that the 6 delays are distributed as unevenly as possible to reach a smeared sound that can resemble a reverb.

 

MN3011 aren't made anymore but there are still plenty available. well maybe not plenty but they're not as rare as like CEM3340 or SSM2044.

[Guest Thisket]

T-t-t-tastey You ought to sell.

[ten fingers ten toes]

This is AWESOME, if you could supply a PCB/component list I would pay for said PCB/component list.

[kokoon]

unfortunately, i can't provide you with either, cause the effect design is copyrighted by Elektor. but if you can get 1990's march Elektor it's all there. there are just a few pretty trivial mods i've done: i've sped up the LFO quite a bit (originally max frequency was like 0.4Hz - way too slow) and added a square waveform to it. then i also extended the feedback options (everything in the "REVERBERATION" section except the first, "FEEDBACK" pot).

 

but essentialy it's Elektor, which isn't that far from the ETI design that you can get all over the net. Elektor's does have different (inductor-based) filters and added pots for separate tap levels. it also features an LFO that ETI doesn't.

 

anyhow, i'll probably be making an extended ETI version also, i'll try to stuff in all the added features (separate pots are trivial, so should be the LFO). at the moment i'm thinking about adding a compander to either of the designs to improve the SNR. i also have an idea about making the effect stereo without the need for 2 BBD chips...

[Guest iep]

WICKED! i think i actually can get that issue of elektor (my school has a huge elektor archive, fucking goldmine).

 

btw here's the link to the ETI mn3011 bbd article http://www.synthdiy.com/files/2003/eti-mn3011reverb.pdf

 

where did you get the pcb? or did you etch it yourself? you reckon it would be possible to build this 100% on vero?

[Guest iep]

'i also have an idea about making the effect stereo without the need for 2 BBD chips...' do tell!

[Guest analogue wings]

 

Maybe something like this ADA unit that lets you send individual taps left or right

[kokoon]

great! let me know if you get it at your school!

 

i etched the board myself, the PCB layout is included in the article. i guess you could also do it on a stripboard but i don't see why. this was my first etched PCB ever and i did it all perfectly in 1st try.

 

the stereo idea - actually it's quite simple: since the BBD provides 6 separate taps already, i could take 3 of them and route them to one channel and the other 3 to the other channel. like 1-3 for left and 4-6 for right. or maybe even better - odd taps for left and even taps for right. both these options would actually provide "true" stereo - unlike some BBD units that just invert the signal for the other channel and when you mix that to mono you're left with no effect :D

[kokoon]

 

Maybe something like this ADA unit that lets you send individual taps left or right

woah nice find! yeah exactly like that.

it's a bit of work though cause i'll have to duplicate the filter too. analogue wings is that ADA STD-1 yours?

[Guest analogue wings]

Nope. They come up for sale on AH from time to time, but are never particularly cheap. They have a CV input I think, which is supar fap material for that group.

[chim]

Nope. They come up for sale on AH from time to time, but are never particularly cheap. They have a CV input I think, which is supar fap material for that group.

 

yeah ive seen some midi retrofits show up here and there though..

[kokoon]

midi for STD-1?

[Guest Glass Plate]

wow, that sounds so good.