## maths for noise added to frequency for analog modeling

Jul 14 2017 | 6:48 pm
I'm trying to find the proper maths to add bits of noise to the frequency of an analog modeling type synth. Namely so when I add this noise to the freq (say between -.1 and +.1) it changes the pitch of the synth the same amount whether the frequency is 55 or 440. I think I need to use logarithmic scaling or something but not positive on how this would work exactly

• Jul 14 2017 | 7:23 pm
you can use mtof for that kind of thing. start working linear, then add that to notenumbers, then mtof.
• Jul 14 2017 | 11:46 pm
Thanks Roman. I tried that but its still sounding off. It works well when I throw a snapshot in there but of course i wanna get it all in signal rate
• Jul 15 2017 | 2:11 am
• Jul 15 2017 | 12:36 pm
noise~ *~ mtof~ ... all available for signal :)
• Jul 15 2017 | 3:56 pm
I suggest using the noise signal as an exponent with a base of 2, and use that as a multiplier to vary the fundamental frequency. In that way, when the noise ranges from -1 to +1, it will cause a pitch variation of ±1 octave, whatever your fundamental frequency. Divide the amplitude of the noise by 1200 if you want to be able to represent pitch variation in cents. The rand~ object provides linearly-interpolated noise, with a new random value chosen at whatever rate you specify.
• Jul 15 2017 | 7:03 pm
mmmmm!! sounds perfect thank you!!!
• Jul 30 2017 | 5:02 pm
I'm trying to build Chris's solution in Gen but for some reason its coming out all wacky. I think there's a problem with the pow object in Gen... or at least how I'm using it. It works great in MSP but... I like building everything in Gen too :D
• Jul 31 2017 | 12:40 am
the MSP pow object has the inlets reversed (compared to the max object), that might be the case for gen, too.
• Jul 31 2017 | 3:09 am
k Ill try that. thanks!
• Jul 31 2017 | 3:19 am
nope that didnt work