dumb 2399 idea

[pinkjimiphoton]

hey bros,

i was thinking yesterday about 2399 based delays, and how at longer delay times, they need less filtering, and shorter, less...

and i was thinking.... why not use a stacked pot, say 100k, use one side for delay time, and use a big muff based one knob tone stack so as the delay time increases, it automatically rolls off highs, and as it decreases, it rolls off lows?

does that make sense? to me, a lot of times longer echoes sound more realistic kinda muddy, and shorter ones sound better bright, like the lead guitar on linda ronstadt's "you're no good"...


any thoughts? obviously values may need to be played with with the caps for best results, but what do you guys think?

just curious!!!

i've got some alternative "fake analog" delay chips i'm thinking about playing with,
and i'm thinking of adapting the delay/reverb and chorus in this groovy cheap kustom i found in someone's trash recently... it's dual 2399 design, one does the delay/reverb (preset pretty much) and the chorus (also preset, but really nice sounding)

anyways... onwards and upwards

[Mark Hammer]

The old MXR green analog delay, and its Ross counterpart did this in the analog domain.  There was one master clock, that got divided down differently for the BBDs and the CMOS switches used for a switched resistor LPF.  The longer the delay time, the lower the filter rolloff.

On the other hand, just think how much more flexibility one would have if the LPF and the delay time were not harnessed to each other.  I mean, yes, an "automatic" adjustment is nice, but what if you wanted a short delay with a really dull-sounding repeat for some reason?

So, for me, far better to just have adjustable filtering that isn't tied to the delay time.

[Scruffie]

I can't remember what it was called by I remember culturejam on FSB designed a PT2399 project that does exactly what you're proposing.

[midwayfair]

I don't think there's a need to roll off bass; it'll sound bright just by not cutting the highs as much.

Juansolo has a PT2399 mod where he uses a single-gang pot as a voltage divider for the time control; one side is the time control, wiper to ground, the other side of the pot is a low-pass filter. As it's turned up, it increases the delay time and decreases the highs. CultureJam used it at least once as well.

[samhay]

I don't think there's a need to roll off bass; it'll sound bright just by not cutting the highs as much.

Juansolo has a PT2399 mod where he uses a single-gang pot as a voltage divider for the time control; one side is the time control, wiper to ground, the other side of the pot is a low-pass filter. As it's turned up, it increases the delay time and decreases the highs. CultureJam used it at least once as well.

I played with this for my reverb design. Works quite well, but found a separate tone control to be more useful.

[pinkjimiphoton]

thanks bros for the info, i love culturejam's designs. some cool stuff, and a great guy.

like most things, it's been done before!!!

i realize a separate control makes more sense, but i was just thinking idiot proof factor... i'd imagine you could get it where it's really only affecting the noise from the chips and not the tone too much.

cool!!