TZF With a Blue Box!

[Geoff Hunter]

....Well nearly.

Ordered some CMOS CD4517 (dual 64 bit Serial Shift Register) with an idea for trying a Digital delay with a 1bit DAC/ADC.  I should have done the maths better first, as I think i would need dozens of them 

Trying to think of something to do with them, brought me this!

Take 1 Blue Box schematic (from www.tonepad.com
add 1 CD4517 for the delay.
add 2 square wave generators http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/square.html

Take the output of one of the Blue Box flip flops (depends if you want one or two octaves) into one of the shift channels and clock with one of the generators.

Take the negative output (switchable with the positive) to the other shift channel and clock with the other generator.

Mix the output of both these to back where the square wave goes back into the BB (where the out from the second flip flop goes) and you get this!



I've got a lot of clock noise problems, and I haven't done the mixing properly (i think the signal can circulate back to the input....)  but its does work.

Heres a sample of it (apologies for the lack of any quality in the playing!)

http://media.putfile.com/TZF-Blue-Box-Sample (Putfile has really decimated the quality, but you can just about hear it).  The funny noises is the blue box mis-tracking!

I think I will re-do it with a proper pcb, but as currently am having to sweep the square wave generators manually (I hooked up my old zoom foot pedal), but I would rather auto sweep.  Can anyone recommend a good LFO+clock generator for TZF?

[Skreddy]

I like the way you think.  The direction you're going is very cool.  You'd probably get more mileage out of phase shifting, but primitive digital flanging is a nifty idea.  Rock on!

[Processaurus]

Very cool idea.  One could use a regular BBD chip too, and forget about all the normal filtering and limits to how slow you can clock it, since you don't have to worry about distortion. 

Sounds kinda like analog synths with two oscilators tuned nearly the same, but not quite, so theres all kinds of shifting cancelations as the two interact.

For an LFO + clock I would lift the one out of the small clone, because it uses a 40xx series chip, so it should be able to just plug in.  You'd have to slow it way down though.

[Geoff Hunter]

Thanks!

To me its got that Commodore C64 like vibe to it!  Currently I'm using a DOD Buzz box and a DOD flanger to get similar sounds, but this sounds nicer to me (because I made it!).

The small clone clocking scheme looks nice and easy, mind you the Electric Mistress one looks nice as well, have to see what parts i've got.  I'll post a schematic once i've got something interesting going.

[Zero the hero]

Nice idea!
I'm going to order a couple of shift-register, too...