The Echoplex EM-1 Groupmaster is a Mike Battle designed four channel mixer version of the storied EP-3 introduced ca. 1970. This rare tape echo combines two of the desirable EP-3 (Jimmy Page tone) preamps with the added functionality of a four input mixer and attractive large UV meter. The mixer allows the operator simultaneous echo signals with different signal gain and tone adjustments to take full advantage of the EP-3s preamp and echo tone. The Groupmaster was the top of the line offering from Market Electronics during Battle’s tenure. While production figures are unknown, the EM-1 Groupmaster is rarely offered for sale. We have sold two previously: serial numbers 12103 and 12140.

This 1971 Maestro Echoplex EM-1 Groupmaster with footswitch has just returned from a full cleaning and service from Pete Grosso with RePete Echo Repair in Los Angeles (@echoplexrepair on Instagram). Pete cleaned and adjusted the tape transport, update filter capacitors, installed a fresh pinch roller, and rebuilt the motor. It’s now in perfect functioning condition with warm, beautiful repeats. The large VU meter is both attractive and aids in dialing the right amount of gain. All the original parts are included in the sale.

This rare tape echo has been cleaned and adjusted and is ready to go in your collection or studio. Pete knows his way around an Echoplex and has serviced many Groupmasters. Rest assured that you’ll be the only one showing up to a gig with an EM-1 Groupmaster.

Do you have an Echoplex for sale? I’m always looking to buy Echoplex machines of all forms. Sell your Echoplex to me here: my buying page.