Tuning the OT ring modulator

Unverified - these are predictions out of the regression model.

Note Hz AMF Fine
B-4 1.93 0 10
C-3 2.04 1 16
C#-3 2.17 2 23
D-3 2.29 3 29
D#-3 2.43 4 35
E-3 2.58 5 42
F-3 2.73 6 48
F#-3 2.89 7 54
G-3 3.06 8 61
G#-3 3.24 9 67
A-3 3.44 10 74
A#-3 3.64 11 80
B-3 3.86 12 86
C-2 4.09 13 93
C#-2 4.33 14 99
D-2 4.59 15 105
D#-2 4.86 16 112
E-2 5.15 17 118
F-2 5.46 18 124
F#-2 5.78 20 4
G-2 6.12 21 10
G#-2 6.49 22 16
A-2 6.88 23 23
A#-2 7.28 24 29
B-2 7.72 25 36
C-1 8.18 26 42
C#-1 8.66 27 48
D-1 9.18 28 55
D#-1 9.72 29 61
E-1 10.30 30 67
F-1 10.91 31 74
F#-1 11.56 32 80
G-1 12.25 33 86
G#-1 12.98 34 93
A-1 13.75 35 99
A#-1 14.57 36 105
B-1 15.43 37 112
C0 16.35 38 118
C#0 17.32 39 124
D0 18.35 41 4
D#0 19.45 42 10
E0 20.60 43 17
F0 21.83 44 23
F#0 23.12 45 29
G0 24.50 46 36
G#0 25.96 47 42
A0 27.50 48 48

I want to control it from C-1 with midi processor. As lfo fine tune values seem to follow the same cycled values I think I can apply these values for lower notes.

Instead of a tuner I can compare with an lfo on Vol (tempo tuning !).

:+1:

Ah so lower fine tune values are slightly different?

I’ve spent no time debugging those. What looks different about them?

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With the tremolo sounds I do think the AMD depth control needs to be at 127 to get the frequency you want. IIRC, the character of the tremolo changes with AMD.

EDIT - I think 64 is right, not 127.

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This is probably a rounding issue. Not sure if it is on the target frequency side or on the FINE value side.

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Not very different in fact. Just rounded differently I guess…

Note Hz AMF Fine
B-4 1.93 0 10
C-3 2.04 1 16
C#-3 2.17 2 23
D-3 2.29 3 29
D#-3 2.43 4 35
E-3 2.58 5 42
F-3 2.73 6 48
F#-3 2.89 7 54
G-3 3.06 8 61
G#-3 3.24 9 67
A-3 3.44 10 74
A#-3 3.64 11 80
B-3 3.86 12 86
C-2 4.09 13 93
C#-2 4.33 14 99
D-2 4.59 15 105
D#-2 4.86 16 112
E-2 5.15 17 118
F-2 5.46 18 124
F#-2 5.78 20 4
G-2 6.12 21 10
G#-2 6.49 22 16
A-2 6.88 23 23
A#-2 7.28 24 29
B-2 7.72 25 36
C-1 8.18 26 42
C#-1 8.66 27 48
D-1 9.18 28 55
D#-1 9.72 29 61
E-1 10.30 30 67
F-1 10.91 31 74
F#-1 11.56 32 80
G-1 12.25 33 86
G#-1 12.98 34 93
A-1 13.75 35 99
A#-1 14.57 36 105
B-1 15.43 37 112
C0 16.35 38 118
C#0 17.32 39 124
D0 18.35 41 4
D#0 19.45 42 10
E0 20.60 43 17
F0 21.83 44 23
F#0 23.12 45 29
G0 24.50 46 36
G#0 25.96 47 42
A0 27.50 48 48
A#0 29.1 49 55
B0 30.9 50 61
C1 32.7 51 67
C#1 34.6 52 74
D1 36.7 53 80
D#1 38.9 54 86
E1 41.2 55 93
F1 43.7 56 99
F#1 46.2 57 106
G1 49.0 58 112
G#1 51.9 59 118
A1 55.0 60 125
A#1 58.3 62 4
B1 61.7 63 10
C2 65.4 64 17
C#2 69.3 65 23
D2 73.4 66 29
D#2 77.8 67 36
E2 82.4 68 42
F2 87.3 69 48
F#2 92.5 70 55
G2 98.0 71 61
G#2 103.8 72 68
A2 110.0 73 74
A#2 116.5 74 80
B2 123.5 75 87
C3 130.8 76 93
C#3 138.6 77 99
D3 146.8 78 106
D#3 155.6 79 112
E3 164.8 80 118
F3 174.6 81 125
F#3 185.0 83 4
G3 196.0 84 10
G#3 207.7 85 17
A3 220.0 86 23
A#3 233.1 87 30
B3 246.9 88 36
C4 261.6 89 42
C#4 277.2 90 49
D4 293.7 91 55
D#4 311.1 92 61
E4 329.6 93 68
F4 349.2 94 74
F#4 370.0 95 80
G4 392.0 96 87
G#4 415.3 97 93
A4 440.0 98 99
A#4 466.2 99 106
B4 493.9 100 112
C5 523.3 101 119
C#5 554.4 102 125
D5 587.3 104 4
D#5 622.3 105 11
E5 659.3 106 17
F5 698.5 107 23
F#5 740.0 108 30
G5 784.0 109 36
G#5 830.6 110 42
A5 880.0 111 49
A#5 932.3 112 55
B5 987.8 113 61
C6 1046.5 114 68
C#6 1108.7 115 74
D6 1174.7 116 81
D#6 1244.5 117 87
E6 1318.5 118 93
F6 1396.9 119 100
F#6 1480.0 120 106
G6 1568.0 121 112
G#6 1661.2 122 119
A6 1760.0 123 125
A#6 1864.7 125 4
B6 1975.5 126 11
C7 2093.0 127 17

This might be helpful for testing:

Target Hz AMF Fine
2 0 93
4 13 42
8 25 119
16 38 68
32 51 17
64 63 94

If your tempo is 60 or 120 bpm, the 2, 4, 8, and 16 Hz values should synchronize.

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Other point: I had a weird result with a stereo white noise thru comb filter + AMF : the RM note was fully on the right !!!

As comb filter induce a strong DC offset I think it changes AMF behavior. Doesn’t explain why it is fully on the right with that particalr stereo white noise sample. I had to use Spatializer fx to make it mono…

Will resample mono.

:+1:

For lfo tuning my reference tempo is 103.1 (103.125 actually), perfectly correspond to 440 hz tuning !

For other pitches I multiply tempo by 2^(X/12), were X is semitone value.

Exemple to get C tempo, 3 semitones above A :

103.125 x 2^(3/12) = 122,637 bpm.

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In the past I’ve noticed some oddities with the Lo-Fi effect on stereo images. It is almost like there is a sample delay between the left and right speaker. I think I noticed it the most with the SRR while modulating it.

I want my lo-fi to be hi-fi. :slight_smile:

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I think you want AMD at 64 for the frequencies to line up on tremolo sounds. 127 will be at double the rate.

Moog → sequenced ring mod → wet-only delay. Just exploring the space.

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I was playing around with the tremolo sounds. On my OT the slowest tremolo with the ring modulator is when AMF = 8. There is a jump in rate when I reduce AMF to 7.

Ah I noticed something weird in that concern when assigning it to crossfader…

Do you mean slow ring mod ? :content:

I wonder if the table it references has some typos! It is really kind of strange.

Not tremolo, definitely a subsonic ring mod. :wink:

Sequencing the ring mod, looping the Moog:

Fun!

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Showing four different octaves of tuned ring mod with four different octaves of source signal. The second half is more musically interesting (marginally!).

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Nice !

Is it a tri waveform?
From Moog ?

I found a way to get pure sine from AMF using @Veets trick. The principle is to get a flat waveform from a square or a dedicated sample :

Without lfo on vol, with the flat signal, ring modulation gives a pure sine. Additionally you can use an lfo on vol and draw a waveform.

Using comb filter on the flat signal also gives a new timbre…

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