Appendix: Technical data
The numbers behind FRIZZ, for planning a setup. The timings were measured on a CHOMPI.
- 48 kHz, stereo in and out, through a 24-bit codec. FRIZZ works in floating point, in blocks of 24 samples (0.5 ms).
- The input: AUX and the mic have their DC taken out, from about 8 Hz down, so a kick or a bass synth keeps its weight; the mic also has its highpass at about 150 Hz. USB’s input comes in as the computer sends it.
- The loop: up to 2:45 of stereo, stored at 16 bits in RAM, gone at power-off (see Looper). Live, the input is floating point up to the safety limiter; what goes into the loop is held just under full scale by a limiter of its own, which takes a peak at once and lets go over about 150 ms. Below that it records exactly what came in. A source loud enough to reach it records a little quieter than it sounds live (from about 7 dB below the input’s full scale at input gain 75%).
- The freezer records up to 5 s; the delay holds 10 s, so 2 bars fit at the slowest tempo.
- The tempo: 50-300 BPM, 120 at power-on.
- Every output has a fixed safety limiter after VOLUME (see Finalizer LEDs and settings).
- The finalizer: its bands split at 300 Hz and 3 kHz, Linkwitz-Riley 4th order; its drive at twice the sample rate; its limiter 1 ms ahead, a ceiling of -1 dB, with its peaks between samples estimated at twice the rate. While Loud is up, the outputs and MIDI clock out are 1 ms later.
- USB audio (see USB audio): USB Audio Class 1 at full speed, 48 kHz, 24 bit, 2 channels each way, asynchronous: the computer follows FRIZZ’s clock, about 2 ms of buffer each way in FRIZZ. To the computer, the master before VOLUME and the safety limiter, at the line out’s level at full VOLUME, clipped only at full scale; from it, the source USB, at the level AUX would have with the same signal at its jack. FRIZZ asks the computer for 100 mA.
- The effects: the shifter lands within about a cent of the interval, its taps lining up within 7.5 ms where they start over, and keeps its highs (a 10 kHz tone a fifth up loses about 0.3 dB). The folder’s sine fold keeps its aliases more than 85 dB down on a sine below about 1.5 kHz at any drive; the triangle’s corners alias, and first-order antialiasing (ADAA) takes 5 to 13 dB off them.
Processing load
Section titled “Processing load”Effects that are off cost little processing time, about 5% of each block’s together (most of it the resonator and the shifter keeping their recent sound for a punch-in), but the ones that are on do. Some heavy combinations (the shifter and the crusher with a loop playing and the finalizer working hard, for example) can need more time than there is, which is heard as crackles; switching one of them off clears it.
Measured on a build that runs a set of combinations by itself, as a share of the time each block has, in the busiest block: FRIZZ alone about 30%, one effect at most about 45%, all the inserts with a loop about 70%, every effect at once about 85%. On average the finalizer with every module working takes about 13% more, its compressors alone (Depth up) about 5%; at its defaults nothing. Every effect at once with a loop, and every effect’s page 2 turned off its defaults (Mix, Band and Level), needs more than there is. A DAW can get there for a moment without a loop: automation that turns every effect’s page 2 off its defaults and then switches the effects on and off in quick succession (by CC 22 or any other way, a few milliseconds apart) has them all running at once, since an effect let go keeps running while it fades out, for about 70 ms, and can crackle for that moment.
Timing
Section titled “Timing”| What | Measured |
|---|---|
| A quantized loop against the clock it was recorded to, over TRS | 0.4 ms a minute at most (1 bar, at 120 and 174 BPM) |
| The same over USB | 4 bars: 0.35 ms a minute at most; 1 bar: from −2.2 to +2.3 ms a minute, depending on the recording |
| A loop recorded to REAPER over USB (87 BPM, 4 bars) | 0.66 ms a minute; every bar within 1.5 ms of the song |
| The effects’ tempo following a clock that changes | 10 BPM within about 0.4 s, 1 BPM within about 2 s |
| The clock source on Auto, its clock stopping | The other input’s clock counts within about 0.8 s |
| MIDI clock out over TRS (120 BPM) | Jitter 0.53 ms; 0.64 ms with MIDI feedback sending 1652 CCs meanwhile |
| MIDI clock out over USB | Its tempo right (120.08 BPM for 120), each tick within about 1 ms, also while a loop loads from the card |
| A clock over TRS with other MIDI right behind its ticks (a chord, a stream of CCs) | Each tick within 0.35 ms of a bare clock’s (95%), a loop’s Start within 0.4 ms |
| A computer’s clock over USB, passed on out of TRS (200 and 300 BPM) | Each tick 0.13-0.16 ms off even on average, 99% within 0.5 ms |
| MIDI feedback | One CC per value every 10 ms at most |
| Switching on | Sound about a second after FRIZZ starts |
Formats
Section titled “Formats”- The card: microSD, FAT32. FRIZZ’s files are text, in the
FRIZZfolder (see Card and files). - Loops: WAV, 16-bit, 48 kHz, mono or stereo, up to about 77 s (see Loops on the card).
- MIDI clock in and out at 24 PPQN. The keys are notes 48 to 72, the knob presses and the other keys below them (see Notes: the keys).
- FRIZZ’s own SysEx starts
F0 7D 43 48(see Remote control).