Spin Semiconductor

Kf = 2^17 (2 pi f / R) f: Desired LFO frequency in Hz R: Sample rate in Hz Kf range: 0 to 511 Kf decimal = Kf / 512 25/512 = 0.048828125 125/512 = 0.244140625 -------------------------------------- Ka = N (32767/16385) N: Delay length in samples Ka range: 0 to 32767 Ka decimal = Ka / 32768 16/32768 ...

writing this down a little bit quick since I need to go out... EQU X2 REG0 EQU X REG1 EQU A REG2 EQU B REG3 EQU TANH REG4 ; X has been calculated and it resides in the register already... LDAX X MULX X WRAX X2,0 ; CALC A LDAX X2 SOF 1, 0.002797202797 MULX X2 SOF 1, 0.1282051282 MULX X2 MULX X RDAX X...

from: https://varietyofsound.wordpress.com/2011/02/14/efficient-tanh-computation-using-lamberts-continued-fraction/ x2 = x * x a := x·(135135 + x2·(17325 + x2·(378 + x2))) b := 135135 + x2·(62370 + x2·(3150 + 28·x2)) tanh(x) = a/b dividing each by 135135 a := x·(1 + x2·(0.1282051282 + x2·(0...

Don, that was very nice of you to share your code. Sounds very good. I saw that in the code you put a question mark after "eigentone". These are the various frequencies that cause resonance in a system. Mechanical systems can have an infinite amount of resonant frequencies. In the spring r...

Do you have an audio clip? I'm curious to hear it.

Iconnu

LOL.....I told you it was way too early for me. I meant "Larry" not "Frank"....sorry Frank. Not your fault.

Yikes....message was edited to correct my mistake

Larry, In the code for the MN3011a you have MULX POT1 WRAX REG20,0.0000000000 SOF 0.1130374160,0.0059798553 WRAX ADDR_PTR,0.0000000000 The wrax instruction is saving pot1 in reg20 and then clearing the acc. In the sof that comes after the acc = 0.0059798553. Why do you have 0.1130374160 in there rat...

Here's some code for one stage: ;y(n) = A * x(n) + A * y(n-1) - x(n-1) ; can be simplified to ;y(n) = A * (x(n) + y(n-1)) - x(n-1) ; A is a function of the LFO or a POT ldax xn ; input to stage rdax ynold,1 mulx A rdax xold,-1 wrax yn,1 ; output of stage wrax ynold,0 ldax xn wrax xold,0

There's a difference between the standard phase shifter effect (N identical stages in series) and what is done in the Univibe (N stages in series, each one tuned differently). I think that's the advantage of having the equation I posted.

Larry, I wanted to post this here because its handy to use when calculating the filter parameters: first order all-pass filter difference equation: y(n) = A * x(n) + A * y(n-1) - x(n-1) Where A =(1 - wp) / (1 + wp) and wp = pi * (frequency / sampling rate) As an example, for frequency f1, we can cal...