When I was a kid in the seventies, the only game in town for echo was the Echoplex. Any guitar with echo you heard in the seventies was probably done on a Plex. Certainly all my guitar hero's back then used one. Just to mention a few: Tommy Bolin, Jimmy Page, Joe Walsh, Brian May, and last but not least, the man with the guitar, James Marshall Hendrix. I couldn't afford one back then, and now I have two.

I did a lot of research and learned a lot. The Echoplex was invented by a man named Mike Battle and had several incarnations:
My first Plex was a 1974 EP-3, given to me by my good friend Maynard. It was in pretty shabby condition when I took possession, it wasn't even working. However, I'm a fool for vintage gear so I went to work on the restoration, see below for a link. My second Plex is an 1968 EP-2 that I acquired in a trade. It is in need of restoration badly which I haven't gotten to yet, see below for a link.

Some notes about the Echoplex
I heartily recommend getting a Plex; there are always several of them on Ebay. Be aware that it will probably need a tune up like I gave mine, and regular maintenance, but its worth it!
The Fantastic Echoplex
Echo chamber
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Since I first put this page up I've had more hits and more response to it than any other page on my website. I've received emails from all over the world with questions and comments about it, and I want to thank everyone for their good wishes. Due to it's popularity I've revamped the page and added several more expanded pages about different issues regarding the Echoplex. Please remember that I am not a trained technician, nor do I do repairs, I am just a DIY homebody that did a lot of research on the Echoplex, then consolidated it here for other Plex owners to benefit from. See below to get started!!!
Here are links to other pages I've done on the Echoplex:
My 1974 EP-3 I refurbished and restored.
My 1968 EP-2.
How to clean an Echoplex.
Build yourself a stand for your Echoplex.
My Echoplex survival kit.
How to reload a tape cartridge.
Repairing a pressure pad.
How to adjust tape bias an Echoplex, copied from the original service manual.
Removing the EP-4 compressor board.
My Commentary on tape and parts availability for the Echoplex.
Mike Battle:1918-2008
A solid state EP-2!!
A tube EP-3!!
Here are some external links:
JOA: Lubricated tape for reloading cartridges, also splicing blocks, Q-Tips,and other cleaning supplies.
Andrews Amp Labs: Jeff takes repairs on a case by case basis, call or email him.
Orbit Electronics: Echoplex repairs and new tape cartridges.
Good page here on cleaning and demagnetizing tape recorders.
Schematic Heaven has the Echoplex service manual and schematics of all the Plex's.
The CartGuys: Another source for lubricated tape. Look for "Echoplex 850-X".
Splicit.com: Splicing blocks and cleaning supplies, also tape.
Articles here and here from Vintage Guitar magazine about the Echoplex.
Article here from Mix magazine by Eddie Ciletti about Echoplex maintenence.
Antique Electronic Supply: Tape cartridges, pressure pads, belts, thumbscrews.
Loop Master has a tape cartridge rewinding service.
Good article from Tape Op about tape splicing.
Terry's Rubber Rollers and Wheels rebuilds pinch rollers, I sent him mine.
Parts is Parts has Echoplex motors and belts.
Plex schematics here.
The late Mike Battle invented the Echoplex.
Small page about the EP-3 and EP-4.
Caig makes the correct rubber cleaner for your pinch roller.