Trend price : 400€
A basic monophonic synthesizer with a superb compact design and a membrane keyboard, similar concept found on EDP Wasp or EMS Synthi.
Overview
portable 25 membrane keys with no velocity but the IMPACT SENSOR circuit which opens filter to major pressure. The EHX synth features 7 sliders potentiometers, 6 two-ways switches and a built-in audio speaker.
Back panel terminal connectors:
- audio output
- master tuning trimmer
Voice
monophonic, single analog oscillator: a voice is composed by a 1 VCO pulse + 1 suboscillator (1 octave lower) which is obtained from divider structure, while octave function switches the VCO to 2 octaves below.
Filter
the VCF is resonant (Q switch) and the 2x switch steps the filters 1 octave up.
LFO
modulation on the VCO pulse rectangular width (PWM).
Envelope
a single EG control on the cutoff filter: the START and STOP sliders set the lower and higher frequencies range at key down and up.
Effect
VCF phase function activates a phase shifting on the sound. The following MK2 includes a neat time delay effect.
Maintenance
after some pressures (and some years) the keyboard usually has some issues: it is necessary to refurbish the contacts using some homemade tricks or directly redisigning a new cardboard.
Audio demo:
Video Clip:
Review
OK: analog / design
NOT : unreliable / limited sound / expensive
" love the design, nice vintage object! bad news: sound is not so compelling, unplayable keyboard and membranes maintenance are major drawbacks."
Text , review, special demos copyright polynominal.com / Eric Pochesci