Selling last and final personal pair (the ones I kept for myself after selling off the whole tower of them I used in Timothee Chalamets Bob Dylan biopic, “A complete Unknown”).

These are the real deal EMI RS124, built from the original elusive EMI Abbey Road reverse engineered schematic. These Altec 436C’s are freshly modified into fabled EMI Beatles compressors ripe for the picking. Full conversion was completed December 2024 and basically stored ever since (about 20-30 hrs burn in completed then stored in my smoke/pet free studio rack). Indescribable sound from the most elusive schematic in the world. Open to trades - direct offers preferred at JML recording dot com.

What is rarer than a pair of RS124 EMI compressors? A sequential serial numbered pair of EMI RS124's, that have never left each others side in 60 years! Matched pair, gutted, fully converted & rebuilt from the ground up with a couple unique custom mods to boot.

Serial #3064 and # 3065

Both units are matched within 0.5 dB from zero to 10dB reduction. Both have been completely reworked to the original EMI schematic of the iconic RS124 Abbey Road Compressors, as seen in the “Recording The Beatles” book. Elusive printed EMI schematic will be included with purchase but not available for sale outside this listing. You’re welcome to come try them out in person in NYC area to hear them before you buy them if you like. No tire kickers on these fragile and delicate grails; all sales final please. No returns.

DESCRIPTION:
There are no greater vari-mu compressor on earth than the EMI RS124’s. These come around very very rarely and very rarely done right. I’ve owned a dozen or so pair in the past and this particular pair is the finest pair yet (details below).

Possibly the greatest pair of compressors available anywhere for sale. In addition to the EMI mods, basic tech work has been performed such as VU repair and calibration, the balance mod, SNR improvment, replaced old audio caps, added extra resistors to increase dynamic range and reduce distortion, output pot mod, replaced the selenium rectifier with silicon, genuine Nuetrik pigtails added, new bulbs, etc. Fuse is intact but moved internally as shown as not to drill the faceplate. The fuse faceplate hole has been repurposed for the output pot. We also used some hand selected, high end matched vintage tubes from GE, Telefunken and Sylvania. Every inch of both units has been addressed or modified.

We stayed true to the EMI schematic with two slight changes to improve them:

First, we doubled the value of the two signal rectifier coupling caps to improve low frequency gain tracking.

Secondly, we had initially assembled and tested the stepped output pots like the EMI schematic calls for (as shown sitting on the schematic sheet in the 4th pic) but we realized that an ordinary 1K audio pot will give you about 3dB more output than the stepped switch! So this particular pair comes with variable sweep output instead of stepped, allowing you drive them a little harder than typically, which provides slightly hotter output at the very top.

OPERATION DETAILS:

How to use the biasing pot mod (little blue box with flathead):

Only do this when the tube is replaced. Never touch them unless you replace the tube! Tubes were more consistent back in the 50’s so input pots and resistors on the way input trimmers reduces second order distortion. All you need is a volt meter by looking at cathodes across pot (.6-2Volts) or watch plate with no signal and no limiting (input turned down). Balance that pot so it’s within a tenth of a volt. Hit it with 1Khz signal between top and bottom of plate. Plates should read 112-118 with full compression. It’ll rise up to 120-140.

Please ask all your questions prior to purchasing, or come try them out in person, ask for recordings, etc BEFORE buying. Far too fragile and valuable to be returned or bouncing around back and forth in a UPS truck! Been there before… never again. Sold “as-is“ in perfect working order. Added worry-free reverb FULL insurance comes free with purchase for the FULL amount. If there’s any shipping damage, you’re covered 100% through reverb (just submit a repair receipt and they pay you, no questions asked). We’ve had an unfortunate run of tire kickers buying high end gear and sending it back packed poorly, which causes shipping damage we are somehow on the hook for. Therefore, it is recommended that you come & try them in person first or ask all your questions prior to purchase and take em with you please. Our commercial recording studio is located 15 minutes from Manhattan New York, where in-person demos of all of our equipment is available, six days a week. Shipping orders will be packed extremely securely.

Reverb takes $500 listing fee and $500 processing fee (yikes reverb, a thousand dollars now?! ) PLUS sales tax… plus income tax now (!) plus initial donor cost of 4k ea, plus 1400 each for the mods (bench time and parts), plus new NOS tubes, etc, I’m making very little believe it or not, so price is very firm. Open to any other barter ideas. Will be packed extremely securely to withstand an atom bomb. Any questions please ask. Thanks for looking. Follow our shop & audio YT channel! Cheers - JML