ELECTRO-HARMONIX Q-TRON Effects Pedal as is this page from

as is this page from the Hiwatt catalogue showing the Slave spec:

an ARP 2600 complete with 3620 keyboard - for sale in excellent working order

Some info from the GML site below

CONDITION: Superb cosmetic condition with only the most minor scuffs and scratches around the face

again no Reverb or EQ

ELECTRO-HARMONIX Q-TRON Effects Pedal as is this page fromOriginal "large box" Electro Harmonix Q Tron Envelope Filter pedal in very good condition and perfect working order, for sale with original wooden box. This pedal is the envelope filter based on the Mu tron III design, and it sounds very similar (certainly better than the terrible Haz Labs reissue Mu tron). Mike Biegel, inventor of the Mu tron recommends this pedal as the nearest equivalent to an original Mu tron. A whole world of funky filtering can