HUM Audio N-Closure 2 (Frame + 2 modules) is a complete two-channel analog processing system — a 4U housing with two N-Strip modules factory-installed, ready to operate out of the box. Each module is electronically identical to the N-TROPHY console channel strip: a discrete Class-A preamp on Jensen JE990 opamps (0–66 dB gain), a switchable input transformer, a THD stage with five saturation types, a tube optical compressor on an ECC88 tube, a 6-band passive EQ with HPF/LPF on rotary switches, an insert loop with Dry/Wet Blend, and an output trim with source selector. The two adjacent modules share a compressor stereo link — both channels can operate with a linked detection circuit, maintaining stereo image coherence under compression. Designed primarily for stereo recording: drum overheads, classical piano, stereo acoustic guitar, M/S pairs. Hand-built in Poland.
Two identical Class-A signal paths — consistent stereo pair
The Mic/Line/Hi-Z preamp based on the flagship RP-2 topology delivers 0–66 dB of gain in 12 stepped positions; microphone input impedance is 3.5 kOhm, line is 10 kOhm, Hi-Z exceeds 1 MOhm; 48V phantom power and phase inversion per input type; Tape input with 0/+6/+12 dB gain switch. An optional input transformer (X-FORMER) engaged via relay between the preamp and EQ adds subtle harmonic enhancement at low frequencies. The THD stage (Germanium, Silicon asymmetrical; Soft/Medium/Hard symmetrical) covers gentle analog warmth through deliberate drive. The ECC88 tube optical compressor with continuous Comp→Lim morph, Dry/Wet Blend, and stereo link between both channels — in stereo link mode both channels share the detection circuit, eliminating stereo image pumping when compressing drum overheads or piano. The tube can be bypassed independently from the compressor. Sidechain options include an internal HPF, KEY1/KEY2 external inputs, and AUX 7+8 as global sidechain buses. The 6-band passive EQ with separate Boost and Cut per band, switchable Peak/Shelf on HF and LF, and HPF/LPF on rotary switches delivers fully recallable, matched EQ across both channels. Processor order is relay-configured independently per channel across six permutations.
Rear panel and system integration
The N-Closure 2 rear panel provides a full complement of XLR and combo sockets for each of the two channels: a global KEY input for external sidechain, insert send/return XLR, and a channel line output with a selectable tap — after the preamp or after full channel processing. A Sifam VU meter per channel displays Post Gain, Gain Reduction, Trim, or Input modes. Each channel has an output trim with source selector and level control, and a 100mm stepped motorized fader on fixed resistors identical to the N-TROPHY. The built-in power supply drives both ECC88 tube compressors simultaneously. The complete two-channel system occupies 4U of rack space and operates as a self-contained dual-channel front-end for any audio interface or DAW. For setups requiring more channels, the N-Closure 6 (11U, 6 slots) is available.
KEY FEATURES
- Complete system: 4U housing + 2 N-Strip modules factory-installed
- 2 identical Class-A signal paths — consistent stereo character without level matching
- Discrete Mic/Line/Hi-Z preamp Jensen JE990, gain 0–66 dB, 12 positions per channel
- 48V phantom power; phase inversion; Tape input 0/+6/+12 dB per channel
- Switchable input transformer (X-FORMER) per channel
- THD Stage: 5 saturation types (Germanium, Silicon, Soft, Medium, Hard) per channel
- Tube optical compressor ECC88 with Comp→Lim morph, Dry/Wet, stereo link per channel
- Stereo link between both channels — coherent stereo compression without image pumping
- Independent tube bypass per channel
- Sidechain: internal HPF, KEY1/KEY2, AUX 7+8 as global sidechain buses
- 6-band passive EQ with separate Boost/Cut; switchable Peak/Shelf on HF and LF per channel
- HPF and LPF 6 dB/oct with frequency selection on rotary switches per channel
- Insert XLR with Dry/Wet Blend per channel
- 6 configurable processor orders per channel (independently relay-switched)
- Sifam VU meter: Post Gain / GR / Trim / Input per channel
- Output Trim with source selector and level control per channel
- 100mm stepped motorized fader per channel (identical to N-TROPHY)
- Rear panel per channel: KEY XLR, insert in/out XLR, channel line output
- Selectable output tap: after preamp or after full channel processing
- Built-in AC power supply supporting both modules with ECC88 tube compressors
- Ideal for stereo recording: drum overheads, piano, acoustic guitar, M/S pairs
- Hand-built in Poland
TECHNICAL SPECIFICATIONS
- Type: complete 2-channel system — 4U housing + 2 N-Strip modules
- Signal path: discrete, Class-A, balanced, relay-switched throughout
- Preamp: Jensen JE990, gain 0–66 dB (12 steps)
- Input impedance Mic: 3.5 kOhm; Line: 10 kOhm; Hi-Z: above 1 MOhm
- Maximum input level: +22 dBV
- Phantom power: 48V per channel
- Input transformer: switchable (X-FORMER)
- THD Stage: 5 types (Germanium, Silicon, Soft, Medium, Hard)
- Compressor: opto ECC88, continuous Comp→Lim morph, Dry/Wet, inter-channel stereo link
- Sidechain: internal HPF, KEY1/KEY2, AUX 7+8
- EQ: 6-band passive, separate Boost/Cut, switchable Peak/Shelf on HF/LF
- HPF/LPF: 6 dB/oct, frequency selectable on rotary switch
- Insert: balanced XLR, Dry/Wet Blend
- Processor order: 6 relay-switched configurations per channel (independent)
- VU meter: Sifam per channel, Post Gain / GR / Trim / Input
- Fader: 100mm stepped motorized (fixed resistors)
- Rear panel per channel: KEY XLR, insert in XLR, insert out XLR, channel line output
- Output tap: selectable after preamp or after full channel processing
- Housing size: 4U rack
- Power: AC mains, built-in supply supporting both modules with ECC88 tubes
- Production: hand-built, Poland
