Q-Tron Plus

Envelope Filter with Effects Loop
Same design as the original Q-Tron but with extremely useful Effects Loop and an Attack Response Switch.

The Effects Loop gives the musician the ability to place an additional effect, or chain of effects between the Q-Tron Plus's preamp and filter section without changing the envelope drive. This is particularly important with most distortion devices, as most all do not have much of an amplitude envelope. The FX loop will also fire up your creative juices to try all sorts of combinations in the effects loop: try the Micro POG into a Deluxe Memory Man. You can invent all sorts of novel effects.

The added Response Switch selects between a slow, smooth, vowel-like attack and the fast, snaked response of the original Q-Tron.


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From the Blog
Posted 12/12/2013



Sonnyonbass lays down a powerful, funky groove with his QTron +.



Posted 3/14/2010

In Effectology 14, pedal guru Bill Ruppert takes us on a journey to previously unchartered sonic territory. Using only Electro-Harmonix pedals and his guitar, Bill creates a series of “believe it or not” soundscapes. Whether it’s the sound of songbirds singing joyfully by a babbling brook or a vintage vinyl “lo-fi” recording complete with clicks and scratches, Bill’s mastery of effects will amaze you. As he says, “Never judge what an effect pedal will do by what you have heard it will do. Experiment and you will find new sounds not yet discovered!” Indeed!

Please note: Bill will be in the EHX Forums to discuss his sounds, settings, and process. We hope you join us there.

Previous episodes:

Stay tuned, more Effectology episodes coming soon!

Posted 6/18/2009
Can you crack the code of Riddle & Enigma?

First clue: Mike Beigel landing EHX color in the remote ice fields of Cape Crozier, Antarctica.

Years earlier, back in 1972, Mike also explored new sonic landscapes as inventor/engineer of the world's first stand-alone envelope filter, the Mu-Tron III. The sound was quickly captured by Stevie Wonder, and made famous by his 1973 funk classic, "Higher Ground."

Here's a vintage 1973 performance:

Despite Stevie's personal endorsement (see right) and other noteworthy users like Bootsy Collins and Jerry Garcia, the maker of the Mu-Tron III (Musitronics) closed shop in 1978. Years later, Mike Beigel decided to bring the original Mu-Tron III mojo over to EHX. Mike picks up the story:

"In '94 I met [EHX founder] Mike Matthews at a NAMM show. We talked about effects pedals, and later he asked me if I'd be interested in re-creating the Mu-Tron III for Electro-Harmonix. The new box which is called the Q-Tron, uses the same opto-electronic design of the Mu-Tron III, with new features and improved specs."

Mike and Mike went on to design the EHX Q-Tron, Q-Tron Plus, Micro Q-Tron, Stereo Polyphase, Bi-Filter -- and now, Riddle & Enigma: mysteriously musical envelope filters for guitar and bass.

What about Antarctica? In that same year (1994) Mike Beigel was also hired to design and build a system to track penguins between their nests on the beaches of Antarctica and their aquatic feeding territories. Mike later traveled to Antarctica to install and troubleshoot his system, and remembered to pack his EHX t-shirt. Mike adds: "And yes, I did work on some EHX designs during my spare time in Antarctica!"

While there, Mike also managed to capture amazing photos of the locals:

Riddle & Enigma: welcome to the family.

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Quick Specs
True bypass
Dedicated effects loop allows you to place any effect or pedal board into the loop
FX send and return without changing the envelope drive
Selectable low pass, band pass and high pass filters
Resonant peak control to adjust the filter's Q from subtle to dramatic
Response switch changes the reaction time of envelope follower from fast to slow
Switchable hi or lo frequency sweep ranges
Adjustable gain knob and boost switch
Sweep direction switch for up or down filter sweeps
Tough and compact die-cast chassis
24DC-100 power supply included
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