Circuit Atlas · HUSH M4 · Rev 2027.4 draft
3 Controls and connections
Channel strip, master section and rear-panel connections, as published for the HUSH M4 draft.
IN DEVELOPMENT · REV 2027.4 (DRAFT) · DESIGN TARGETS, NOT MEASUREMENTS
HUSH M4 is in development. This draft is published on zakkhutoretsky.com; it has no price and no ordering. Figures marked design target are goals for the finished product. Figures marked calculated come from the published formulas. No value on these pages was measured on a built unit. Interviews are cited as the design brief, not as an endorsement.
See this control Front panel key Play the panel Channel 1 controls
3 Controls and connections
Channel strip (×4, identical)
| Control | Range / action | Notes |
|---|---|---|
| Input select PH / LN | Switches the strip between phono (RIAA, S1) and line (S2) | Four phono stages: any deck can go on any channel |
| TRIM | −15 dB to +15 dB on line (-14.9 to +14.3 calculated) | Set so the level LEDs peak in the amber |
| HI / HI MID / LO MID / LO | HI and LO: full kill to +6 dB. HI MID and LO MID: −27 dB to +10 dB. Centre (12:00) = exactly 0 dB, with a centre detent | HI shelf 3 kHz, HI MID bell 1.1 kHz, LO MID bell 350 Hz, LO shelf 180 Hz (S13). In the browser model: double-click or press Delete / Enter to reset |
| FILTER | Counter-clockwise: low-pass sweep. Clockwise: high-pass sweep. Centre dead zone: filter out of the circuit (relay true bypass) | 12 dB/oct, low resonance (Q 0.71), no peak |
| CUE | Sends the strip pre-fader to the cue bus | Latching, lit when on |
| Channel fader | 60 mm; sets the VCA control voltage | Replaceable. Audio does not pass through the fader. |
| Level LEDs | 11 segments per channel (green, amber, red) | Read the post-fader signal |
Master section
| Control | Range / action | Notes |
|---|---|---|
| MASTER ISOLATOR LOW / MID / HI | Full kill to +6 dB on the whole mix | Split and band amps as in S3b; the channel EQ (S13) reuses the split at 180 Hz |
| MASTER | Master output level | Feeds master XLR and the record RCA |
| BOOTH | Booth output level | Own balanced driver |
| CUE / MIX | Blend between cue bus and master in the headphones | SPLIT CUE puts cue in one ear and master in the other |
| PHONES | Headphone level | 6.35 mm and 3.5 mm jacks, usable at the same time |
| TEXTURE / MODE | Amount (zero is off) and a mode button with LED: Clean SVF, Ladder, Comb, Bitcrush | Optional section, S11 |
| FX SEND 1–4 / RETURN | Per-channel send to the spatial FX bus; one return level (zero is off); mode, time / size, feedback / decay and tone | Optional section, S12 |
| METER DIM / DARK | Dims meters and legends to low amber | For dark rooms |
| MONO | Sums master to mono | For checking phase on mono systems |
| FX LOOP | Send level, return level, in / bypass | Out of circuit when off |
Connections
| Connector | Type | Level / impedance |
|---|---|---|
| Phono in ×4 | RCA, unbalanced | MM, 47 kΩ, load capacitance switchable; chassis ground terminal |
| Line in ×4 | RCA, unbalanced | Nominal −10 dBV to 0 dBV; trim ±15 dB |
| Master out | XLR, balanced | +28 dBu maximum (target), 95 Ω |
| Booth out | XLR, balanced | As master |
| Record out | RCA, unbalanced | Line level, fixed |
| FX send / return | 6.35 mm, unbalanced | Nominal 0 dBV |
| Headphones | 6.35 mm and 3.5 mm | 250 mW into 32 Ω (target) |
| USB-C | USB Audio Class 2.0, optional | Record 4 channels plus master; playback to rear line outs (S10) |
| Power | Locking multi-pin input from the external linear supply | Mains inlet, fuse and protective earth are on the supply; chassis bonded to earth |