Technical Specifications for tape used on Echoplex machines

For 3M 156 Back Lubricated Open Reel Audio Tape

3M Scotch 156 Back Lubricated tape as was "possibly" used in Roland and other cartridge type echo units including Echoplex, according to what little information is available on the World wide web!

Noted from a spec sheet pdf of the many types of 3M Audio Tape, and year introduced.

Product Number: 156
Year Introduced: 1972
Binder Type: E
Oxide ctg colour: Brown
Base Material: Polyester
Base Thickness: 0.92 mils
Oxide Thickness: 0.27 mils
Total Thickness: 1.3 mils
Back Treated: Lubricated Tape
(flux lines I/4"): 0.5
Rel Rem Lvl
re 3M111(dB): -2.1
(oersteds): 280
(gauss): 1150
Special Feature: Back Lubricated Tape (lubricant unknown)

Useless information provided by John Beer of Amp-Fix for those who might wish to know more about these things. Don’t ask me what it’s all about, look it up on Google!
PDF Spread sheet available via the link below:

THE PLOT THICKENS! I HAVE NOW FOUND OUT THAT THE BACK LUBRICATED BACK TAPE has a graphite-based back coating, as I was informed by Mr. Gene Bohensky of The Reel to Reel Warehouse who supplies and restores reel to reel tape of various types. An interesting website for those of you interested in the history of analogue tape since time began.

A similar type of tape was used for the manufacture of the infamous 8 track endless loop cartridge tapes that had a brief spell of popularity back in the mid 60’s until about 1982 when they were "phased" out. (excuse the pun) From what I gather the tape used was not of a particularly high quality, and was prone to snagging and tangling and in my opinion any surviving cartridges unless in well and truly hermetically sealed original packaging, should not be used to rewind your Echoplex cartridges.

With that information at hand and some further rooting around on the web, the name ATR came up with, 5" spools of 100 ft ¼" back lubricated tape for echo units. Below is the exact wording from their advertisement which is still available at the time of writing - late August 2023. The following is probably copyright, but it’s as is and its now a free advert for them, when they’ll probably be bombarded with orders from people reading this document!

"This product listing is for 1 ATR Echo Tape - 1/4" x 100 Foot Lubricated Tape with Graphite Backcoat on a 5" Plastic Reel. Echo Tape - 1/4" x 100' Lubricated Graphite Backcoat This is specifically designed for Echo Loop Musical Devices. The first newly manufactured echo tape for your tape delay machine. 100 feet of tape on a 5" reel. After multiple series of tests, ATR Magnetics have created a lubricated tape that will last and won’t bunch! Please Contact us directly for bulk quantity lengths and pricing. We recommend calibrating your tape delay machine after install to get the best results of our Echo Tape. $59.95 Each"

Excluding shipping, from the USA and tax and handling fees imposed by Royal Mail and HMRC, a little simple maths, equates to $0.5995 USD or 48p GB per foot. All you have to do then is to wind it very carefully into your old cartridge housing, after thoroughly cleaning the spools and the inside housing and cover. And that I can tell you is quite a task!

If the original tape is past its best but not broken or tangled, the easiest way to rewind it is to note the direction it feeds into the cartridge, cut it, then splice the new tape on to it and run the machine until the tape comes out of the other end. Cut off the old tape where you made the temporary join, and then splice the 2 new ends together on the graphite side and you should be ready for the next 150 years of uses! But you didn’t get to clean the spools or the cartridge housing.

Don’t call me, I’ll call you! 😊

Shamrock 041 & Concert (Radio Shack)
Both made by Ampex as a budget brand but are apparently graphite backed.

The information above was from several hours of research, by me: John Beer of Amp-Fix, having agreed to resplice a couple of Echoplex cartridges for a rather ungrateful customer who thought I could just untangle the originals and resplice the joins. One was an original EP cartridge with about 20 miles of screwed up tangled tape in it. The other was a much shorter Fulltone ETC-1 which was also tangled and twisted I had expected a few problems but the customer during a phone call thought it would be an easy fix "IF he could find someone" who might be able to do it! I estimated £20 IF it was a simple splice repair as he seemed to think it would be! When I saw the mess I was tempted to send them straight back to him, which on reflection, I should have done! But I was always one to accept a challenge, so rang him to discuss my findings and recommendations that both cartridges needed to be dismantled, cleaned and reloaded with fresh tape. I didn’t give him a price but knowing the cost of new ones and that it was more of an exercise for me, there was no way I was planning to rip him off. I bought from eBay an 8 track cartridge that appeared to be in good condition, opened it up and the tape looked good no frayed edges, creases or evidence of any damage. So proceeded to do the Fulltone first as it didn’t have that many turns on it, can’t remember off hand how many but probably 20 or 30 as opposed to several hundred on the original EP one. After a few attempts I managed to wind on a similar amount of tape and buttoned up the Fulltone cart. Them proceeded to the EP one which was more difficult to take apart as the lid had been glued on along its entire perimeter as well as the four retaining lugs! I eventually got it apart and it was filthy inside much more oil residue in it than in the Fulltone, and what seemed like bloody miles and miles of tape! Anyway, I wound on a fair old whack of the 8 track stuff, about half of the original amount buttoned it up and contacted the customer who then offered to pay me the £20 quid I had quoted for splice repairs! So I suggested £20 each 40 quid in total. He hit the roof and became very aggressive towards me. I never knew the guy yet did him a favour by taking the job on in the first place, had I charged him 80 quid it wouldn’t have been out of the way, but he was really nasty about it, so I offered to sent the Fulltone one back free of charge and for me to keep the original for my efforts. After a few days he sent me a cheque for £40 which once cleared I returned both cartridges and have not heard a word from the ungrateful b------ d since, but he’s been entered in my little black book!

This article, written some while ago, is for information only, I’m not offering to reload any Echoplex type cartridges, there is information and images on the internet of how you might go about it. I just did it by hand on a table top without any turntables, blocks of wood, or any other homemade or special equipment, just a lot of swearing and determination!

Quite honestly, I think there is a lot to be said for a normal Copicat type tape loop machine. Cheap as chips or you can make them yourself, job done!

Information from John Beer of