RB 500
Single Pultec Style EQ
RB 500 is a compact passive equalizer inspired by classic Pultec designs, reimagined for the 500-series format. Featuring fully passive filtering based on 1960s analog equalizers, it delivers rich low-end weight and smooth high-frequency enhancement in an ultra-compact module. Transformer-balanced input and output using IGS Custom transformers, combined with a discrete driver stage, ensure musical tone, stability, and headroom. With independent frequency selectors for low boost and cut and a true bypass switch, RB 500 provides authentic analog equalization and characterful tone shaping in a space-efficient modular design.
Classic Pultec-Style EQ in 500-Series Form
RB 500 translates the essence of classic passive equalizers from the 1960s into a single-slot 500-series module. Its design stays true to vintage principles, delivering musical curves and natural tonal balance.
Fully Passive Filtering with Modern Reliability
The entire EQ section is passive, allowing the filters themselves to shape tone without active amplification. This results in smooth, organic equalization that feels natural and forgiving.
Transformer-Balanced Signal Path
IGS Custom transformers on both input and output provide proper isolation, headroom, and harmonic richness. A discrete driver circuit ensures stable output levels and consistent performance.
Flexible Low-Frequency Shaping
Separate frequency selectors for low-frequency boost and cut allow precise sculpting of bass content, from adding weight and warmth to tightening low-end response.
True Bypass for Instant Comparison
A true bypass switch enables immediate A/B comparison, making RB 500 an intuitive and effective tone-shaping tool for tracking, mixing, and creative sound design.
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Specifications
| Stepped Manipulators | Yes, frequency selectors |
| Boost / Cut Range | ±15 dB |
| Hard Wire Bypass | Yes |
| Q Factor | 0.5 – 4 |
| Audio Transformers | Yes, IGS Custom |
| Input Impedance Balanced |
1 kΩ |
| Output Impedance Balanced |
600 Ω, IGS Custom transformer |
| Operating Level | +4 dBu |
| Maximum Input Level | +20 dBu |
| Maximum Output Level | +22 dBu |
| Noise Level | −99 dBA |
| Frequency Response | 5 Hz – 20 kHz ±0.1 dB |
| THD+N | 0.012% |
| Power Consumption | 3.5 W |
| Shipping Weight | 1 kg |
















