Mixing and effects

Balancing eight channels from eight knobs, the two effects every channel feeds, and the handful of settings that belong to the machine rather than to a channel.

What it is

Every channel carries its own reverb and delay send on encoders 7 and 8, feeding two shared effects. Sixteen insert hosts in total — a TAP Stereo Echo and a TAP Reverberator on every one of the eight channels.

The sends are post-fader, so pulling a channel down takes its tail with it rather than leaving a ghost of it hanging in the reverb.

A send number is an amplitude, and it behaves the way a mixer would lead you to expect. 100 is unity — the wet as loud as the signal feeding it. Halving the number takes off 6 dB, so 50 is −6, 25 is −12, and 10 is −20. 30 is a normal, clearly audible send, which is where most of these want to sit. 0 is off.

There is no boost at the top: 100 is unity and the knob stops there. A wet return louder than its own source is not something you should be able to ask for by turning a knob to the end.

Try it

1. Press CONTROL. Encoders 6, 7 and 8 are LEVEL, REVERB and DELAY on every channel, whatever it plays.
2. Hold ALL and turn encoder 6. The row becomes eight LEVELs, one per channel, and the page indicator reads ALL LEVEL. That is the page for balancing, and it is a hold rather than a place.
3. Let go, put your hand on encoder 7, then hold ALL again. Now it is eight REVERB sends. Encoder 8 gives you eight DELAYs the same way.
4. Tap ALL instead of holding it and the lens latches. Tap it again to drop it.
5. Move CUTOFF on a voice and hold ALL. Three columns answer and five draw dead — the drums have no filter to reach. See below.
6. Press VOLUME. Now the eight encoders are the machine's globals: ROOT, SCALE, BPM, WALK, SPAN, MASTER, REVSIZE, DLYTIME.

How it works

A page is eight verbs on one channel. The lens is one verb on eight channels. That is the whole grammar of the surface, and it is why there are no mixer pages to go looking for: hold ALL and whichever verb your hand last moved lays itself out across the eight channels, then let go and you are back where you were. Every channel verb can be looked at that way — the sends, the filter, swing, play chance, how much rope a channel is given — without the instrument growing a page for each.

A channel that does not carry that verb draws dead, in the usual way: ----, a lower-case name and no bar. So CUTOFF across the eight is three live columns and five dead ones, and LANE is the other way round. Turning a global — BPM, ROOT, MASTER — or a name like KIT or PRESET does not move the lens, because there is nothing to lay side by side; it stays on whatever it last held, and before you have moved anything at all it shows LEVEL.

ROOT and SCALE wait for the bar, like everything else that changes what the pattern is. The rest of the globals land instantly. They wait for the voices specifically — each takes the new key at its own next wrap, and the value shows in brackets until the last one has. Switch all eight channels to drum behaviour and there is nothing left to wait for, so the key takes at once and no bracket is drawn; the same happens to a bracket already showing if you switch the last voice away while it is up.

Group button brightness tracks each channel's level, so the row shows the balance without reading anything — and the peak meters on the display run live.

DROP — everything falls away but the ones you kept

Hold ARM — that is SELECT — tap pad 1, then tap a length. The gesture itself is on The surface; this is what lands.

The Group buttons nominate the survivors while ARM is held. Tap A–H to add or drop a channel from the list, and the Group row stops reporting the mix and reports the nomination instead: full for a survivor, dim for everything else. While the modifier is down that row answers one question and no other. The list sticks between holds, so a kick-and-bass drop stays armed the way you left it.

Nominate nobody and the drop refuses. It used to mute all eight, which is literally what nominating nobody means — and is how the instrument once fell silent in the middle of a take. Now it lands, changes nothing, and says so: the page indicator reads DROP 0/8 for the length you armed, which is the same “took none of eight” the timing macros use when they cannot move every channel. A macro that does nothing and does not admit it is the same fault as a silent channel that will not say why.

On the landing bar every channel you did not nominate is muted. It is the mixer strip, not the sequencer — the same mute F1–F8 set — so it takes each channel's reverb and delay tail with it, and the tabs of the silenced channels draw dashed for as long as it runs. A silent channel still says why, even in the middle of a performance.

The length is both numbers. Arm a drop over four bars and it fires four bars from now and lasts four bars. There is no second gesture for the duration.

What comes back is exactly what was there. The mute picture is captured the instant the drop fires and restored unchanged — never "everything on". A channel you had muted by hand before the drop is still muted after it.

Cancelling during a drop leaves the mutes where they are. The return is itself pending, and ERASE + SELECT cancels everything pending — so cancel mid-drop and the room stays quiet. Lift the mutes with F1–F8.

BREAK — fall out now, come back on the bar

BREAK is DROP with its two ends swapped. Arm it and the channels you did not nominate fall silent immediately; they come back on the bar the length names. It is the breakdown you fall into rather than build to, with the drums returning exactly on the one, counted for you.

Everything else is DROP’s: the same survivors on the Group buttons, the same snapshot of who was already muted, the same restore. The length means only when it ends — there is no waiting for it to start.

Only one of DROP and BREAK can be armed at a time. They share one snapshot of the mutes, so arming either drops the other.

The master insert — one filter across the whole mix

Put a filter on the Main chain and VOLUME → MAIN reaches it. It sits between the mixer and the card, so it hears everything: all eight channels, their reverb and delay, the drop, the ramp, everything.

The factory snapshot ships with it. 019-dub-factory is what a fresh install boots into, and it carries an MDA RezFilter on the Main chain, inherited from the 018 it is built on — so the MAIN page is there from the first power-on, with no plugin to add and nothing to load. That changed on 2026-08-22; before it, the factory snapshot left the Main chain empty and the page was not built at all.

017-generative-techno is installed beside it, and it is the same instrument without the filter. Load it and the MAIN page simply is not there — VOLUME’s ring has one page fewer rather than a page of dead columns. That is the way back if the master filter ever gets in your way, and it is the reason shipping the filter by default is safe rather than a trap.

Its main fader ships at 28, not 100, and that is deliberate. 019 at unity peaked +7.0 dBFS and put 1.21 % of its samples over full scale — the kick and the clap, against a crest factor near 18 dB, not a hot mix. Pulling the main down 11 dB lands that peak back at about −4 dBFS — measured on the running instrument over forty-eight bars with nothing clipped — which is the ceiling the mix was tuned to before its sends were corrected. Every ratio between the eight channels is untouched. Turn it up if you want the level; just know that the top of it clips.

In 018 and 019 alike the filter loads wide open and inaudible. That is deliberate rather than incidental — at the plugin’s own factory settings the cutoff sits below the point where it stops passing audio at all, so the snapshot writes every one of its controls explicitly instead of trusting a default. A plugin you add by hand does not get that treatment, so check its cutoff before you decide the rig is broken.

If the instrument ever goes completely silent with every channel looking healthy, look here first and open the cutoff. It is the one control on the rig that can silence all eight channels at once, and below roughly a third of its range it is genuinely silent rather than just dark.

One instance, not eight — which is why it is affordable at all. The per-channel reverb and delay sit on every chain, so an effect there costs eight times what it looks like.

The reverb and the delay have pages of their own on VOLUME, and they are built the same way. Past GLOBAL and PENDING, VOLUME’s ring carries a generated page per shared effect — REV for the reverb, DLY for the delay, MAIN for the master insert when there is one — reaching every port the plugin publishes that GLOBAL does not name, with the tab row carrying parameter names instead of channels. REVTYPE and DLYFBK live there rather than on GLOBAL: one is the reverb’s own list of rooms and the other is the delay’s feedback, and each belongs beside the rest of its plugin. One turn moves that port on all eight chains at once, which is the only way a ganged effect can be steered from eight knobs.

The effects this is proven on

The same insert pair sits on all eight chains, so an effect costs eight times what it looks like. That is where this Pi runs out of headroom — not on the synths. Every plugin below has been measured running eight-up on this rig.

Nineteen different pairs ship across the seventy-one presets, chosen for character now that the knobs find whatever is loaded. Only one pair supplies all six FX controls — TAP Stereo Echo into TAP Reverberator — so most presets give one up, and it is nearly always REVTYPE, whose 43-room list exists on that reverb alone. On a preset whose reverb already is a particular room, a room selector is redundant; that is the trade. Two others cost more and are taken deliberately: a delay that takes a normalised time cannot be locked to the grid by DLYTIME (the dub presets accept that, because feedback is the dub control), and a crossfade has no separate dry.

The knobs find the effect, whatever it is

Until 2026-09-04 the REVERB and DELAY encoders looked their plugin up by name, and only TAP Reverberator and TAP Stereo Echo answered. Load a snapshot with any other pair and both knobs did nothing, both kinds of modulator sat inert, and REVSIZE, REVTYPE, DLYTIME and DLYFBK were dead — with no message anywhere. It was true of twenty-one of the fifty-one genre presets and all twenty of the drone ones.

The two verbs resolve by role now: the driver walks the chain and takes the first plugin that can be a reverb, and the first that can be a delay. Position is never consulted — the old packs put a reverb in the first insert slot on eight presets and a chorus in the second on four, so “slot one is the delay” would have been wrong for twelve of them.

What the REVERB and DELAY columns show is the effect itself, not a number the panel keeps on the side. They used to draw a stored value that began at zero and was never read back, so a preset could be plainly wet while the column read 0 — and because a knob starts from the number it is showing, the first click wrote 1 and took the send with it. Both columns read the plugin now, the way LEVEL has read the mixer since 2 September, so what you see is what is sounding and a turn carries on from there. A modulator bound to either verb captures the real send too, instead of pulling it to zero on its first tick. A channel whose effects cannot supply a send shows the only number there is rather than inventing a zero.

Three things this cannot fix, and the surface says so rather than pretending:

• REVTYPE exists on TAP Reverberator alone. Its list of 43 rooms has no counterpart on any other reverb here, so on a chain carrying a different one that column draws dead.
• Six of the effects below are crossfades, not sends — Shiroverb, Roomy, Modulay, GxEcho-Stereo, Regrader and Gxdigital_delay_st have no separate dry control, so turning their wet up turns the dry down. The knob is held below full travel on those, deliberately, so it cannot delete a channel’s dry signal outright.
• DLYTIME reaches the delays that speak milliseconds. Tal-Dub-3 and Regrader take a 0–1 delay time instead and carry their own host-sync controls, which this project has not measured — so the musical division skips those two rather than writing a number that means something else. Their feedback and wet still work.

What eight instances actually cost

Measured on the rig at 512 frames and 48 kHz, with eight synths playing and only the insert pair changed:

Why plugin GUIs are off, and how to switch them back on

A reverb doing nothing can burn three quarters of a core. Zynthian hosts any plugin that ships its own screen in jalv.gtk3, and when a modulator writes to such a plugin, that host's idle loop spins — not the audio. Measured on this rig: with plugin GUIs on, one house preset cost 189 % of a core and the single modulated reverb sat at 80 % while its seven identical siblings sat at 11 %. With the GUIs off, the same preset cost 97 % and that reverb dropped to 10 %, level with the others. The sound is identical — same plugin, same audio thread.

Eight of the twelve effects in the packs ship a screen, and 50 of the 71 presets aim a modulator at one, so this is the normal case rather than a corner. The installer therefore turns plugin GUIs off, and the Zynthian UI's own remote screen on :6080 is unaffected — only the engines' desktop on :6081 goes.

The webconf checkbox at INTERFACE → UI Options → Enable VNC Server is the same switch by another route. status prints the host binaries actually running: jalv.gtk3 in that list means the GUIs are on for those chains.

Five that are out, and why

Each was proven guilty by elimination — its partner in the pair measured clean elsewhere — and each was replaced in the presets that carried it. Loading without an error is not running without a glitch, which is the whole reason these numbers exist.

Watch what a plugin calls a wet control. Several well-known reverbs turn out to crossfade dry against wet rather than offering a send, so turning the mix up takes the dry signal away with it. The factory pair was chosen by measuring that with an impulse, one plugin at a time. If you swap in your own, check it the same way before trusting the REVERB and DELAY encoders.

What it refuses, and why

Five of the eight columns draw dead under the CUTOFF lens. Only the three voices answer it. The drum channels run a sampler, and there is no filter in that chain to reach — so rather than offering a knob that would do nothing, the columns grey out.

There is no drum filter in this version. That is worth saying plainly so you do not go hunting for one: filtering drums needs a filter plugin per channel, which costs eight more plugin hosts, and it has not been built.

EXIT — a part that leaves rather than stops

A mute is a switch. It is also the sound that gives a machine away: an arrangement made of mutes announces that somebody pressed a button, because nothing in music stops that abruptly except a fault.

EXIT is encoder 8 of the AUTO page, on both kinds of channel. One setting per channel, in bars. At HARD — where everything starts — a mute is the mute you already know. Set it to 1bar or more and that channel closes instead: over the bars you asked for it gets darker and then quieter, and the part is gone by the end of the bar rather than at the instant you pressed.

The gesture is one you already have. Hold MUTE and press the pad on the bottom row — the queued row, the one that has always waited for the wrap. The top row stays instant, so the grid now offers both: cut it now, or let it leave. Bringing it back works the same way and opens it again.

It comes back at the level it left from. A channel you had at 40 opens again at 40, not at full, and a close that has landed leaves the fader exactly where you set it — closing a part is an arrangement gesture, and an arrangement gesture that quietly rewrote your mix would be worse than no gesture at all.

The five drum channels close on level alone. They have no filter to close — their chains are the sampler, the echo and the reverb, and the only filter on the instrument sits on the main bus. The three voices get both, and the difference is audible: a voice closing sounds like a door, a drum closing sounds like a fade. That is what the instrument can honestly do today rather than a setting somebody forgot.

See also

• Modulation — the lens is the best place to bind eight modulators at once
• Sound and presets — LEVEL, REVERB and DELAY per channel
• The surface — modes, pages, how the ring works, and the ARM gesture DROP rides on