A couple words on the VCF-1 and sequencer meanderings (long)

[Andrew Schrock]

I had said a while ago that I would post on the subject of Tony Allgoods
filter PCB once I got mine done. Nobody else posted a review, so I'll pick
up the ball and do so. 

It's taken me far too long to get the board populated.. the main problem
was getting the pots. Apparently there aren't too many options for some
types of pot stateside. (dual-ganged log pots) I had to do some tricky
lead bending to get the ones I got to fit, but in the end they worked
fine. (spectrol and clarostat) 

I have to say the finished product is exceptional. The filters feel is  
infinitely more "alive" than my peavey spectrum filter, and the input
overdrives very nicely for very rough distorted sounds (if desired). Very
small knob twists result in rather different sounds. The resonance isn't
overbearingly loud or harsh as in some filters, but really quite pleasant.
The cumulative sound is very organic, as a filter should be. The organic
quality is helped considerably by the number of modulators available:
envelope follower, AD/AR envelope generator and LFO. My peaveys lack of an
LFO has been a longtime complaint of mine. 

The entire unit is nice and quiet, especially compared to other filters, 
due to the very high quality of the parts and PCB. (double sided PCB,
board-mounted pots) I did screw L-brackets to the front panel to take some 
stress off of the pot leads, but this is as yet the only modification.
Perhaps later I'll add a ringmod, but then again perhaps it's a little
redundant since it's in my modular rack which already has 3 of its own. 

To sum up in a crude manner, running drums through the filter gives me a
stiffy. It will definitely get daily use in my studio as anything from a
pseudo-compressor to just warming things up a bit. I'll still use my 
spectrum filter because of its midi implementation for pad filtering, but 
the VCF-1 is an excellent compliment. Thanks, Tony! 

Also, I've been thinking about putting together a sequencer. At minimum it
would have to be 8x2 steps and run on midi or internal clock, but I would
really like a 16x3 (retaining the option to split to 2x8) with the first
knob controlling duration, the second frequency c/v, the third an
arbritrary c/v (filter cutoff, amplitude, whatever), and each step have a
gate with optional trigger out. This is really inspired by working with a
Buchla modular, so you can see where I'm going with this. 

I'm now thinking about doing it digitally despite my lacking in knowledge 
of most things digital. With all this talk of cheap encoders, this would
be an easy way to go. The obvious problem with this would be the stepping 
of the c/v outs if I turn the knobs in real-time.. but perhaps I will have
to accept that as a limitation if I go with this architecture. 

It would be cool to have the note duration knob be able to select a
duration incremented by 1/16th notes. Same with the frequency knobs, altho
again this limits the tone outputs to a standard 12-tone set. 

Obviously if I go digital I could store and recall sequences, which is a
huge bonus, and have a rudimentary LED display, perhaps 2 sets of 2
numeric LEDs. Maybe I could even get patches to switch remotely. The
drawback is that all these encoders will be semi-expensive... even those 
cheapie panisonic encoders will run $150 for 16x3 of them. Anything
higher-quality could increment that figure substantially. 

O' course all of the above requires that I heckle my digital-friendly
friends and pick their brains for info. Just throwing it on the floor for
comments.. has anybody done this before? From what I've seen this is
evolving in my mind to look a lot like the Doepfer MAQ16. 

later, 
Andrew

-| Andrew Schrock | aschrock at cs.brandeis.edu |-