Gristleizer PCB group buy? Who's interested?

[Skruffyhound]

I'll be paying for 2 boards tomorrow, 26 dollars 50 cents to Europe right? Good Job

[Ben N]

Payment sent (1). Thx, Taylor.

[montezuma]

Payment sent for two boards. Thank you!!!

[Strategy]

Paypalled for two. This shall be the cornerstone of my forthcoming Throbbing Gristle cover band, "Pulsating Tissue". Just kidding, but I am stoked about the boards!!!

- Strategy

[Taylor]

Ha! I wonder why you don't see tribute bands to people like TG. Would be funny to see the industrial equivalent of this guy.

Here's the build info as it stands currently. If you guys want to look it over, and see if there are any typos or things that aren't clear, that would be a big help. Also let me know if you think of important information that I left out. I've asked gaussmarkov if we can put his schematic in the PDF, but haven't heard back.

[Strategy]

A bunch of the Analogue Heaven list dudes in Seattle had a killer Kraftwerk cover band, analog/modular everything...

- Strategy

[markeebee]

Paid for two.

Thanks a lot Taylor, I hope to return the favour sometime.

[tiges_ tendres]

Hooray for an awesome new project!

I too have forwarded a payment for my boards.

Thanks again.

[Skruffyhound]

I've payed for two. Thank you

[Stompin Tom]

Payment sent. Thanks!

[Derringer]

paid for two.

thanks again!

[Roy]

There was a question about adding a resonance control to the filter.

It's not that kind of filter. The classic synth filter is a four pole low pass, with four coincident real poles. If you put feedback round it, the poles spread out to make it more bandpass. This one is a 'multifeedback' filter, which is already bandpass. It's not particularly sharp, and the Q varies with frequency. Its main virtue is the very simple circuit.

You might be interested to learn where I got the idea for the filter.

http://c73.student.utwente.nl/sjoerd/audio/leesvoer/pdf/Basic%20Active%20Filter%20Circards.pdf

Sheet 8 is the one. I'd just bought this pack of circuits, and it ignited my teenage brain with all sorts of possibilities. The DPDT switch to reconfigure between this VCF and a VCA is all my own work. That and putting a FET in to take the place of the variable resistor. But those cards were quite inspirational.


Roy Gwinn

[jacobyjd]

Interesting.

Mine sounds like a phaser with the resonance cranked way up--the only thing I would really change about it would be to lower the range of it a bit.

However, one thing I noted when playing around with it is that if you roll off the depth, the 'dry' filtered signal is pretty much set at the lowest range of the 'wet' filter. This improves it, but a deeper sweep would be nice. I might jigger around with the caps on one of the new ones I build.

[Taylor]

Hmm, interesting. I always want to add more controls to anything I build, so some way to change the sound of the filter would be nice. Maybe a rotary to select some different caps would be a cool mod?

Once people start building these and coming up with tweaks I will be adding them to the PDF. I think I'll also start a new thread for building and modding, because I find these long threads to be difficult to navigate, and people end up not reading the earlier posts and asking the same questions over and over.

[Roy]

Not a bad idea at all to vary the caps. I'd make the steps approx an octave apart. 6n8 is where it is now, perhaps add 15n (one octave down) and 33n (two octaves down), and try 3n3 (one octave up).

I wouldn't switch it though. For the cost of the switch, you might as well build multiple parallel VCF circuits, and mix the outputs. That allows for the possibility of running more than one bandpass at the same time, which can sound really nice. You'd need to match the FETs so they track together.

Roy Gwinn

[jacobyjd]

Roy, you should probably stop posting good ideas. :-P

[Skruffyhound]

LOL 

[jacobyjd]

My order is in for 2

[Ben N]

And so, the Gristleizer boards (mostly black, a few green) went forth from Nawlins to conquer the Earth!

[Taylor]

Hey guys, that moment is here:



Sorry for the junky scan, I don't have a camera at the moment. The boards are here. Ordering info is here.

All the boards ordered so far will probably ship tomorrow. Thanks guys! Looking forward to seeing your completed Gristleizers.