Zoë Blade's notebook

900 Series (Behringer)

900 Series tech specs

Behringer 900 Series in custom walnut case
Behringer 900 Series in custom walnut case

Behringer released the 900 Series in 2020. These modules are clones of the Moog 900 Series synthesisers, and as such have been nicknamed Boog by some fans. As with other Behringer clones of the era, they're conveniently shrunken down to Eurorack format.

The general consensus seems to be that they sound like the Moog 900 Series, but don't act like them. Recommended modifications include replacing the rather erratic pots with more consistent ones that allow smooth operation,[1][2][3] and replicating the original's trunk lines and busses to reduce the need for micromanaging connections.[4] There's also a rather nice 904A mod that makes it sound like a 1967-era original.[5]

Behringer's designers did slightly improve upon the original here and there. For example, the 902 VCA's positive and negative inputs and outputs are clearly labelled, rather than a fun surprise like on the original 900 Series.

The main thing to watch out for is calibrating the oscillators. They're not temperature compensated, so they drift as they warm up — not just their offset, but also their range.[6] At time of writing, Nina and myself just spent several hours getting them spot on outside of the case, and now that they're back in the case, their ranges are all perfectly off by the exact same amount.


Model Type HP Description
902 Module 8 VCA
903A Module 4 White and pink noise
904A Module 8 Lowpass VCF
904B Module 8 Highpass VCF
911 Module 8 ADSR envelope generator
911A Module 8 Dual trigger delay
914 Module 28 Extended range fixed filter bank (12 bandpass, 1 low, 1 high)
921 Module 14 VCO (Doubles as LFO)
921A Module 8 Oscillator controller
921B Module 8 Oscillator
923 Module 8 Highpass and lowpass filters / White and pink noise
960 Module 56 Sequential controller
961 Module 21 Interface
962 Module 8 Sequential switch
992 Module 8 Control voltages / attenuator
994 Module 4 Multiples
995 Module 8 Attenuators
1630 Module 14 Frequency shifter
CM1A Module 6 MIDI to CV converter
CP1A Module 4 Power supply
CP3A-M Module 14 Mixer / multiples
CP3A-O Module 8 Front trunklines / attenuator
CP35 Module 21 Normalled attenuators / CV sources / multiples


  1. "Behringer System 55" SkyWriter, Mod Wiggler, Oct 2020
  2. "Behringer System 55" SkyWriter, Mod Wiggler, Oct 2020
  3. "Behringer System 55" SkyWriter, Mod Wiggler, Oct 2020
  4. "Moog Modular Routing" Rob Keeble, Dec 2021
  5. "Behringer 904A Rewinds to 1967" Rob Keeble, Nov 2020
  6. "Behringer System 55" BowserB61, Mod Wiggler, Sep 2020




Analogue step sequencers: 100 Series (Behringer) | 900 Series (Behringer) | Sequencer Complement | System-100 | System-100M

Behringer: 100 Series (Behringer) | 900 Series (Behringer) | ADA8200 | K-2 | MS-1 | Model D | RD-6 | RX1602 | VC340

Eurorack: 100 Series (Behringer) | 900 Series (Behringer) | A-100 | Concussor

Modular synthesisers: 100 Series (Behringer) | 900 Series (Behringer) | 900 Series (Moog) | A-100 | Concussor | Sequencer Complement | System-100M | The evolution of the 900 Series