[sdiy] Hiss, Crackle, and Pop

[Tom Wiltshire]

Thanks for the positive vibes, Brian. I'm a fan of assembly language in general, and for some reason I've never got on with C. Since I've learned probably over a dozen programming languages over the years, it's nothing to do with programming, but it just doesn't click with me.
For the little PICs, assembly is a good fit, since if you're doing something that's complicated enough to need C, you should be using a bigger chip!

On 3 Apr 2017, at 23:29, rsdio at audiobanshee.com wrote:

> p.s. I like the idea of noise passing through a Decay-controlled VCA, because that's very drum-machine. However, if you really want to simulate pops on vinyl then I think it would be more accurate to skip the noise source entirely, and just connect the DC Control Voltage from the Decay envelope to the audio. Maybe a little bit of Attack or slew limiting to tame things differently than a first-order low-pass might. I think this would simulate the way the needle is deflected on the vinyl surface when a damaged groove passes underneath. Since you're allowing the end user to "adjust to taste," maybe the option of skipping the noise would be useful.

Yes, this is a good idea. I sort-of tried it on the breadboard, since I had DIP switches connecting the PGC/PGD programming pins to the rest of the circuit. These pins are used as two of the noise outputs. If you program the chip and then forget to switch the DIP switch back to 'on', what you hear is the just the envelope CV feedthrough thumping. With a bit of tuning, you could definitely do it like that.

Tom