The Behringer 297 is a precise analog recreation of the Roland System 100M 297 Dual Portamento Controller and CV Utilities module from the early 1980s. This compact 16 HP powerhouse combines two independent portamento (glide/slew) circuits for smoothing CV transitions (like pitch slides between notes) with two four-channel CV mixers featuring attenuators, normal/inverted outputs, and built-in ±10 V offset sources—essential for blending modulations, creating complex CV shapes, adding offsets, inverting signals, or processing LFOs, envelopes, sequencers, and more in any Eurorack setup.
Technical Specifications
| Item | Description |
|---|---|
| Type | Legendary Analog Dual Portamento/CV Utilities Eurorack Module |
| Eurorack Width | 16 HP |
| Depth | 38 mm (1.49″) |
| Weight | Approx. 0.4–0.5 kg (0.88–1.1 lbs) |
| Power Requirements | Eurorack bus (10-pin or 16-pin connector) |
| Current Draw | +12 V: 70 mA, –12 V: 60 mA, +5 V: 0 mA (some sources list 40 mA +12 V / 30 mA –12 V; verify with your PSU) |
| Dual Portamento Sections (identical) | |
| Type | Independent slew limiters / portamento controllers (DC-coupled for pitch or CV gliding) |
| Controls per Section | PORTAMENTO TIME knob (manual glide time: ~10 ms – 3 s) |
| Inputs per Section | 1 × Signal In (3.5 mm TS, DC coupled, ~95 kΩ unbalanced, max +10 V) 1 × CV In (for voltage-controlled glide time) |
| Output per Section | 1 × Signal Out (3.5 mm TS, DC coupled, ~250 Ω unbalanced, max +10 V) |
| CV Mixers (2 identical, 4-channel each) | |
| Inputs per Mixer | 4 × 3.5 mm TS (DC coupled), each with individual attenuator knob Inputs 3 & 4: normalled to fixed +10 V and –10 V respectively (if no jack inserted) for built-in offsets |
| Outputs per Mixer | 2 × Normal (non-inverted) outs (3.5 mm TS, DC coupled, ~50 Ω unbalanced, max ±10 V) 2 × Inverted outs (phase-reversed) |
| Additional I/O | |
| Total Patch Points | Portamento: 2 × (Sig In + CV In + Out) = 6; Mixers: 2 × (4 Ins + 4 Outs) = 16; grand total ~22 jacks |
| LEDs | None (classic 100M minimalist design—no indicators) |
Key Features & Signal Flow
- Two independent portamento circuits — Smooth abrupt CV changes (e.g., sequencer steps to gliding pitches on VCOs); manual time control plus CV input for dynamic, modulated glide rates—great for expressive leads, portamento basslines, or slew-limited envelopes.
- Two 4-channel CV mixers — Blend up to four modulation sources per mixer with precise attenuators; fixed +10 V / –10 V on channels 3/4 enable easy bipolar offsets without extra modules.
- Normal and inverted outputs — Each mixer provides both positive and negative versions of the summed signal—ideal for complementary modulation (e.g., one to filter cutoff, inverted to another destination) or creating complex interactions.
- DC-coupled throughout — Handles audio-rate signals or slow CV equally well; use portamento for subtle portamento effects or as slew for sample & hold smoothing.
- Classic System 100M utility — No-frills, all-analog design for reliable CV mangling, offset addition, inversion, and gliding—essential for modulation routing, voltage offsetting, or building pseudo-LFOs/envelopes from simpler sources.
- No normalisation — Fully patchable: route sequencer CV through portamento for slides, mix multiple LFOs/envelopes, invert for negative modulation, or mult offsets to multiple destinations.
- Versatile applications — Glide between sequenced notes, offset filter envelopes, blend random voltages from S&H, invert LFOs for opposing sweeps, or create custom modulation curves.
Resources
- Official Behringer product page: https://www.behringer.com/product.html?modelCode=0720-AAJ
- Quick Start Guide (PDF): Available on Behringer downloads or direct link like https://notebook.zoeblade.com/Downloads/Documentation/Behringer/297_Dual_Portamento_CV_Utilities_quick_start_guide.pdf
- ModularGrid page: https://modulargrid.net/e/behringer-system-100-297
- Retailer pages (Sweetwater, Thomann, B&H Photo, Alto Music): Detailed specs, user reviews, demo videos, and patch examples
- Demo videos: Search YouTube for “Behringer 297 Dual Portamento CV Utilities” (feature overviews, glide demos, mixer patching ideas)
The Behringer 297 is a compact, indispensable utility module—delivering authentic Roland glide smoothness and powerful CV mixing/offset/inversion tools at a fraction of vintage prices. Perfect for polishing modulation in a System 100 clone or expanding any rack’s control voltage capabilities. Highly recommended for serious patching!
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