Alright, I figured it was time for me to throw my hat in the ring.
Yes, yes, this is a reverb but before you get too excited, some HUGE CAVEATS:
- This is a chain, NOT a custom unit, and therefore trying to control/tweak is a nightmare;
- If you are not familiar with FDN Reverb topology (schroeder, gerzon, jot) it might be worth looking up before trying to understand the architecture. In particular, I wouldn’t recommend changing the gain structure anywhere but the top level.
- I fully expect to get my wrists slapped by our senior unit-making folks for the way I built things up. I basically had to do it this way in order to keep my place.
The chain hits about 55-60% on the 48kHz firmware (4.01).
With all of that sombreness out of the way, here are some more fun notes about this thing!
A) It is indeed a 4N Feedback Delay Network Reverb, roughly utilising the Jot 1991 generalised FDN algorithm.
B) I chose a 4x4 Householder Matrix for the FDN part.
C) Instead of trying to make a single pole LPF (Brian, help!!), I just used the eq3 as an LPF ahead of each delay, as well as a ‘shaping’ eq3 at the end of chain in order to provide feedback control and some tone shaping.
D) The delay times are mutually prime, and if you want to change the sound of this thing without getting into the hairiness, I’d recommend pulling up a list of prime numbers and just fooling around for awhile. It’s fun.
E) I can’t remember if I put limiters ahead of the delays, but they should be there, the cubic one is good.
F) ‘Convention’ would typically have us put allpass filters in front of each LPF, but again I chickened out. I have a version sitting on my box that tried to incorporate them, but I’m not sure I built them correctly and I don’t think it sounds better than this one.
G) Oh - it’s only mono-mono. Sorry about that. However, I think the architecture will acommodate mono-stereo, and potentially stereo-stereo but I’m not doing any of that until I can encapsulate it in a custom unit (definitely worth waiting for).
So, for the adventurous - go have a look, and maybe let’s improve the architecture?
For everyone else, the chain still loads up and it’s still fun to mess around in there. Something like this would have been impossible (for me) without the scope mode, so sincere thanks to Brian for keeping his eye on these things.
4x4 jot hh mono mod2.chain (101.9 KB)