IGS RB 500 ME
Stereo Pultec Style EQ
RB 500 ME (Mastering Edition) is a stereo passive equalizer in a double 500-series format, delivering classic Pultec-style tone with mastering-grade precision. Built around fully passive filtering inspired by 1960s analog equalizers, it features transformer-balanced I/O using IGS Custom transformers and a Class-A driver stage. Separate frequency selectors for low-cut and boost sections provide exceptional flexibility, while premium potentiometers and ELMA switches ensure accuracy and repeatability. RB 500 ME allows engineers to sculpt tone musically, adding depth, weight, and character without sacrificing clarity or stereo integrity.
A Stereo Passive EQ for Mastering Workflows
RB 500 ME is the first true stereo Pultec-style equalizer designed specifically for the 500-series format. Housed in a double-slot module, it offers the depth and musicality of classic passive EQs with the convenience of modern modular systems.
Classic Passive Filtering with Modern Precision
The entire filtering section is fully passive, closely mirroring revered analog designs from the 1960s. Independent frequency selectors for low-cut and low-boost sections allow nuanced shaping that feels natural and intuitive.
Transformer-Balanced Class-A Signal Path
IGS Custom input and output transformers, paired with a Class-A driver circuit, provide headroom, stability, and rich harmonic structure. This architecture preserves low-end authority while maintaining openness and detail in the highs.
A Tool for Sonic Personality
RB 500 ME excels at adding character without excess. Its multiple tonal interactions invite experimentation, giving engineers a powerful way to imprint personality onto mixes, stems, and masters.
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Specifications
| Stepped Manipulators | Yes, frequency selectors |
| Boost / Cut Range | ±20 dB |
| Hard Wire Bypass | Yes |
| Q Factor | 0.5 – 4 |
| Audio Transformers | IGS Custom (input and output) |
| Input Impedance Balanced |
10 kΩ |
| Output Impedance Balanced |
600 Ω |
| Operating Level | +4 dBu |
| Maximum Input Level | +20 dBu |
| Maximum Output Level | +22 dBu |
| Headroom @ +4 dBu |
18 dB |
| Noise Level | −99 dBA |
| Frequency Response | 20 Hz – 20 kHz ±0.1 dB |
| THD+N | 0.012% |
| Crosstalk | 75 dB |
| Power Consumption | 7 W |
| Shipping Weight | 1.5 kg |












