Electro-Acoustic Research - Model 41

Electro-Acoustic Research - Model 41

  • $225.00

in june of 1992, nyle steiner designed an updated version of the filter
found in his synthasystem, a revision that was never fully completed,
and intended for his evi. in the fall of 2008 the model 41 began as a
joint effort with nyle steiner based on this design and slated as a
limited edition module to celebrate the 5 year anniversary of plan b.
as with other modules planned for that year, the m41 was never released.

in jan of 2014 the collaboration resumed with a few design additions
suggested to him: ifm sync (the "twin" function found in the m11), a
hyper q regeneration function, a +/- bipolar vc input, vc resonance and
level independent lowpass, bandpass and highpass operation, along with
all benchmarks true to the original evi filter design including a
variable intensity control (spectral energy distribution), a four pole
18-stage diode ladder for 24db/ oct response, output oscillation
bandwidth of .5hz to 16khz suitable for lfo or vco applications,
user-scalable 1volt/oct tracking, and full incorporation of integrated
verses discrete transistor amplification architecture.

renamed the steiner 4p, the net result of this old and new technology
pairing has produced a split personality which duplicates all the grit
of the original design taken to levels of distortion and deformity never
before possible in a steiner core.


Frequency manual control (range .5hZ to 15kZ)

Bipolar (+/-) Frequency modulation on input attenuator

Filter Resonance manual control

Frequency modulation voltage control on input 2

Frequency modulation input 2 Std attenuator – 1v/oct manual adjust

Filter Resonance Voltage Control Input

IFM Sync Frequency Modulation mode

Spectral Energy Distribution Enable

Spectral Energy Distribution control

Hyper Q Resonance Modulation mode

Hyper Q Resonance Modulation polarity (-/+)

Output Mode Level Attenuators (Lowpass, Band Pass, Highpass)


60 mA +12V

14hp wide