Delay/reverb/echo

[fredmerts]

Since we are utilizing square waves, has anyone used a D Flip Flop to create a delay/echo/reverb? I'm not sure it could be done, but after reading a bit about D Flip Flops, it seems possible. I'm an electronics newby so please be kind!

[Top Top]

I'm very interested to know as well. It seems that you could do a chorus type of effect at the least...

I am not sure about full on reverb because you need a decay to get a realistic reverb sound... Perhaps in combination with some sort of VCA you could get that type of effect, but it is a little bit hard for me to wrap my head around completely... or actually... now that I think about it, if you had several discreet stages of delay, each with increasingly higher value resistors to give lower amplitude, you could get something like that? I don't know how many stages of repeat you have to have to get reverb-like sounds...

this is an interesting page that sort of displays it what is going on in terms of the inputs and output:

http://www.sheffield.ac.uk/physics/teaching/phy107/dff.html

I often wonder about these sorts of things as well, because most of my ideas for lunetta-type devices come from having messed with the logic processing modules in the nord modular, which does include a logic delay module. I wonder how much of what you can do with logic processing in the nord modular can be replicated with cmos... it would seem most of it, but I don't know enough about cmos to say.

[fredmerts]

Ha! That's the very same page that got me thinking about a delay line. It would be cool to have a low budget, lofi echo to go with these circuits. I guess I have to get out my breadboard and try it sometime.

[electri-fire]

[Sam_Zen]

The pulse width modulation is the trick to get a delay.
The monostable multivibrator CD4098 is one.
Of course, as said, the width should stay within the width of the clockpulse,
otherwise it would skip.
A matter of triggering the next circuit with the 'falling edge' of the 4098.

[slabman]

For an echo/delay, you'll need to clock the flip-flops, and each one will delay the incoming signal by one clock cycle. Let's say you have very lo-fi clock signal (thus sampling rate) of 6Khz. You'd need 1,500 flip flops to make a half-second delay. Analogue delay chips do something similar in the analogue domain and come in delay length from 1024 to 4096 steps. Digitally, it's more usual to have and ADC, RAM and a DAC. RAM chips are cheap. I think UK magazine Everyday Electronics published a DIY delay using a PIC chip as controller a couple of years ago. That design would be open to some experimentation