EE reel to reel tapes

[Robzie70]

Guys, can you get me a list of EE tape makers with list of EE tapes? Thank you! :)*reelspin*

[TheReeler]

Maxell, Basf and TDK. Akai also remarked Maxell tape as "Akai".

Maxell - XLII
Basf - LP35 "EE"
TDK - SA
Akai - EE-150

[Des-Lab]

Well all EE tapes have been out of production for ≈20 years now. It was a tape that never really took off and as far as I know, there were only three makers of it: Maxell with the XLII (last one available), TDK with an SA, and BASF had one as well but the model # escapes my memory at the moment. There was also an Akai branded EE tape complete with Akai reel with EE emblem stamped on it. However it was merely XLII tape in disguise. So it wasn't really "another" brand.

[Robzie70]

Very thanks for the answers guys! :) *reelspin**reelspin*

[hifispock]

The general feeling I'm getting on these forums regarding EE tape is confusing. It seems that most r2r users think that EE tape isn't as good as "standard" tape, or that the "Extra Efficiency" is barely noticeable. Does anybody actually prefer EE tape, and is happy to pay the premium for it?

I see that TDK supplied their excellent "SA" tape on quarter-inch...on a revealing enough system, I would have thought it "spinetingling".I'm sure most of us are aware what a difference SA was/is to AD in the cassette world, so surely, it would be amazing at 7.5 or 15ips.

So could somebody tell Me if I'm right in thinking that EE tapes are CrO2 formulation...And My Akai "wide range" switch is specifically for CrO2?

Thanks in advance :)

[TheReeler]

I see that TDK supplied their excellent "SA" tape on quarter-inch...on a revealing enough system, I would have thought it "spinetingling".I'm sure most of us are aware what a difference SA was/is to AD in the cassette world, so surely, it would be amazing at 7.5 or 15ips.

I don't know where I have it, but ReVox did an exhaustive test about "EE" tape and the conclusion was that only was better at speeds of 3.75 ips and lower, but NO when you were using 7.5 ips and upper speeds, where good ferric oxide formulation tapes were superior.

[supertape]

I don't know where I have it, but ReVox did an exhaustive test about "EE" tape and the conclusion was that only was better at speeds of 3.75 ips and lower, but NO when you were using 7.5 ips and upper speeds, where good ferric oxide formulation tapes were superior.

Where do you have this opinion from Revox?

Is is difficult, if it is not a simple way not to accept that Japanese have not only come to an international level but were leading.

Both the older A77 and B77 or STUDER machines were not capable of recording on EE.

In cassette tape, the Japanese were best, with 7 multilayer metal.

[TheReeler]

Where do you have this opinion from Revox?

Is not an opinion, I readed some years ago a study signatured by ReVox with all the tests and their conclusions. I think it was shared in ReelToReel or DieSpulenTonbandFreunde Yahoo groups, don't remember which one and possibly I have it archived somewhere in a CD-R.

Anyway, not only Studer preferred conventional tapes in open reel (however they produced cassette decks capable of any type of tape), most brands chose just the ferric tapes.

[Des-Lab]

The general feeling I'm getting on these forums regarding EE tape is confusing. It seems that most r2r users think that EE tape isn't as good as "standard" tape, or that the "Extra Efficiency" is barely noticeable. Does anybody actually prefer EE tape, and is happy to pay the premium for it?

I see that TDK supplied their excellent "SA" tape on quarter-inch...on a revealing enough system, I would have thought it "spinetingling".I'm sure most of us are aware what a difference SA was/is to AD in the cassette world, so surely, it would be amazing at 7.5 or 15ips.

So could somebody tell Me if I'm right in thinking that EE tapes are CrO2 formulation...And My Akai "wide range" switch is specifically for CrO2?

Thanks in advance :)

For reel to reel tape, it isn't/wasn't as good. Back when it was new, there was a lot of fanfare and promise of great potential that simply never materialized. EE tape (or which there were only two or three made) were NOT CrO2 tapes. They were the exact same chrome equivalent tapes as used in their cassette counterparts but slit to quarter inch and lengthed accordingly.

You can NOT use EE tape (properly anyway) on any deck that does not specifically SAY EE. Many decks over the years had a number of bias/eq settings like "Low Noise", "Wide Range", "LHI", "Hi Output", etc. Those are all great for trying to figure out the cacaphony of which CONVENTIONAL tape to use. But again. I want to reiterate. If you do NOT see the specific designation of "EE", it is NOT an "EE" deck.

[hifispock]

For reel to reel tape, it isn't/wasn't as good. Back when it was new, there was a lot of fanfare and promise of great potential that simply never materialized. EE tape (or which there were only two or three made) were NOT CrO2 tapes. They were the exact same chrome equivalent tapes as used in their cassette counterparts but slit to quarter inch and lengthed accordingly.

You can NOT use EE tape (properly anyway) on any deck that does not specifically SAY EE. Many decks over the years had a number of bias/eq settings like "Low Noise", "Wide Range", "LHI", "Hi Output", etc. Those are all great for trying to figure out the cacaphony of which CONVENTIONAL tape to use. But again. I want to reiterate. If you do NOT see the specific designation of "EE", it is NOT an "EE" deck.
Ok...Thanks.

If TDK were using the same tape of varying width on their SA reels and in their SA cassettes then does'nt that mean they are both CrO2?

If "EE" isn't CrO2, what is it's formulation? Were there ever any "metal" tapes, or R2R's capable of playing them?

So on My little Akai GX4000D...when do I use the "low noise/wide range" switch? Is it like a bias switch on a tape deck, and sets up the machine for a certain type/formulation, or is it giving Me the choice of wide range with hiss, or low noise with reduced treble?

Thanks :)

[Jay Pemberton]

Ok...Thanks.

If TDK were using the same tape of varying width on their SA reels and in their SA cassettes then does'nt that mean they are both CrO2?

If "EE" isn't CrO2, what is it's formulation? Were there ever any "metal" tapes, or R2R's capable of playing them?

So on My little Akai GX4000D...when do I use the "low noise/wide range" switch? Is it like a bias switch on a tape deck, and sets up the machine for a certain type/formulation, or is it giving Me the choice of wide range with hiss, or low noise with reduced treble?

Thanks :)

SA has never been a chromium dioxide formulation. Like the Maxell UD XL II tapes, it's a cobalt-doped ferric tape. As they were designed to give optimum performance with the same bias levels as for true chrome tape, they sometimes are spoken of as 'chrome bias' tapes.

There never were metal-particle reel tapes; in the 1930s there was a machine called the Blattnerphone which used 6.25 mm steel tape though.

If the GX4000D is anything like my GX 630 D the 'low noise/wide range' switch alters the recording equalisation somewhat, not the bias.

[Kent T]

EE was championed by TDK, Maxell, Teac and Akai during the early 1980's.Otari, ReVox, Studer, Lyrec, Nagra, Stellavox, and Tandberg didn't manufacture machines using EE tape. Advantages were said to be better slower speed performance at 3 3/4 IPS. Advantage wasn't realized fully. This idea would have likely been successful if the timing had been 10 years earlier. By 1980, cassettes took over for most home use and the open reel market for home use was dwindling to a small cadre of enthusiasts like me.

[cabraham]

The EE tape type was clearly intended for low speed consumer recording. It was a type 2 tape, equivalent to type 2 cassettes. BASF used a true CrO2 particle, & Maxell & TDK used ferricobalt equivalent (FeCo).

Obviously, EE was never aimed towards the pro/semipro market. For 1 thing, all 3 brands of EE were only offered in 1.0 mil thickness, the choice for home recording. Pro & semipro users bought 1.5 mil thickness. This reduces print through & has less tendency to stretch/break, important at high winding speeds w/ 10.5 in reels.

Also, only the BASF brand of EE tape offered back coating. TDK & Maxell did not offer back coating on their EE tapes, but did on their ferric oxide conventional tapes. The ferric tapes offered back coating as well as the 1.5 mil thickness, clearly aiming for pro use.

All multitrack & high speed (7.5/15/30 ips, half track) mastering decks I've ever seen or heard of did not offer EE capability. All EE decks were low speed (3.75/7.5 ips), quarter track. Again, this tells us that EE was a consumer format.

Still, EE was a good idea. I agree w/ a previous poster that had it been brought out 10 yrs. sooner, it may have had a bigger impact. It did what it claimed. The FeCo or CrO2 tape could accept higher hf levels before saturating, i.e. better hf headroom. On playback, the eq time constants were lower (less treble boost) resulting in higher s/n ratio. Tests confirmed that EE at 3.75 ips could match ferric at 7.5 ips. NAB eq for 7.5 ips was 50 usec, & for 3.75 ips it was 90 usec. EE eq was 35/50 usec for 7.5/3.75 ips resp.

So home recording of LP records for preservation could be done at half the speed. This not only saves tape cost, but head wear is greatly reduced. At twice the speed, the drag force on the head is twice. Also, twice the length of tape passes over the heads at higher speed. So the head wear is 4 times greater at twice the speed. Also, playing times are extended.

The downside to half speed EE recording is that hf loss due to azimuth error is greater at 3.75 ips by 4 times (vs. 7.5 ips). Also, wow & flutter at 3.75 is greater, EE type not being able to correct for these issues. Still, EE provided some substantial benefits. If brought to the market in 1970 (instead of 1980), it would have likely caught on.

At high speeds, ferric oxide is the better choice. At low speeds, CrO2, FeCo, & metal have higher saturation levels, i.e. MRL/MOL. Ferric oxide actually has lower distortion than all others until MOL is reached. The ferric MOL is lower than the others at low speed.

But at high speed the MOL is very well above 0 dB, so that ferric gives lowest distortion levels. Also, hf losses at high speeds are slight w/ ferric, but great at low speeds. EE can do quite well at 7.5 ips, & a little better at 15 ips. But 15 ips is where premium mastering tapes like 3M 250/226, Ampex 456, etc. really shine. At 3.75, these mastering tapes are quite poor, as they are optimized for high speed.

Did this help at all? Comments/questions welcome.

[Elite-ist]

The EE tape type was clearly intended for low speed consumer recording. It was a type 2 tape, equivalent to type 2 cassettes. BASF used a true CrO2 particle, & Maxell & TDK used ferricobalt equivalent (FeCo).

Obviously, EE was never aimed towards the pro/semipro market. For 1 thing, all 3 brands of EE were only offered in 1.0 mil thickness, the choice for home recording. Pro & semipro users bought 1.5 mil thickness. This reduces print through & has less tendency to stretch/break, important at high winding speeds w/ 10.5 in reels.

Also, only the BASF brand of EE tape offered back coating. TDK & Maxell did not offer back coating on their EE tapes, but did on their ferric oxide conventional tapes. The ferric tapes offered back coating as well as the 1.5 mil thickness, clearly aiming for pro use.

All multitrack & high speed (7.5/15/30 ips, half track) mastering decks I've ever seen or heard of did not offer EE capability. All EE decks were low speed (3.75/7.5 ips), quarter track. Again, this tells us that EE was a consumer format.

Still, EE was a good idea. I agree w/ a previous poster that had it been brought out 10 yrs. sooner, it may have had a bigger impact. It did what it claimed. The FeCo or CrO2 tape could accept higher hf levels before saturating, i.e. better hf headroom. On playback, the eq time constants were lower (less treble boost) resulting in higher s/n ratio. Tests confirmed that EE at 3.75 ips could match ferric at 7.5 ips. NAB eq for 7.5 ips was 50 usec, & for 3.75 ips it was 90 usec. EE eq was 35/50 usec for 7.5/3.75 ips resp.

So home recording of LP records for preservation could be done at half the speed. This not only saves tape cost, but head wear is greatly reduced. At twice the speed, the drag force on the head is twice. Also, twice the length of tape passes over the heads at higher speed. So the head wear is 4 times greater at twice the speed. Also, playing times are extended.

The downside to half speed EE recording is that hf loss due to azimuth error is greater at 3.75 ips by 4 times (vs. 7.5 ips). Also, wow & flutter at 3.75 is greater, EE type not being able to correct for these issues. Still, EE provided some substantial benefits. If brought to the market in 1970 (instead of 1980), it would have likely caught on.

At high speeds, ferric oxide is the better choice. At low speeds, CrO2, FeCo, & metal have higher saturation levels, i.e. MRL/MOL. Ferric oxide actually has lower distortion than all others until MOL is reached. The ferric MOL is lower than the others at low speed.

But at high speed the MOL is very well above 0 dB, so that ferric gives lowest distortion levels. Also, hf losses at high speeds are slight w/ ferric, but great at low speeds. EE can do quite well at 7.5 ips, & a little better at 15 ips. But 15 ips is where premium mastering tapes like 3M 250/226, Ampex 456, etc. really shine. At 3.75, these mastering tapes are quite poor, as they are optimized for high speed.

Did this help at all? Comments/questions welcome.

Hi cabraham,

Now, that's a comprehensive opening post! Thanks for the information you have provided. For a few beginners to R2R, as myself, it's nice to be able to lean on some of the others for advice.

Welcome aboard!

Nando.

[Wilhelm]

BASF actually used chrome "EE" tape in half-inch and 1-inch widths as LPR 921 Bin Master tape for the professional duplication market. The master tape that fed duplicator slaves recording cassette pancakes was originally a ferric tape. If the recording of the master were at 7.5 ips, the sound from the master was quite good; but if the master were recorded on ferric tape at 3.75 ips, there was the typical loss of SOL. The chrome 921 Bin Master gave a far superior performance at 3.75 ips in terms of SOL, and the recordings from those masters showed a noticeable improvement in terms of sound quality. The 921 ran in the bin at 300 ips, so wow and flutter and azmuth were not a problem! It was a concept that was beginning to take off until Concept Design developed a digital bin loaded with solid-state memory. The improvement with the digital bin recording onto analogue tape was dramatic; and the tape, both ferric and chrome, could take another 2-3 dB of signal without any increase in distortion because the peaks were much cleaner and free of modulation skirts that drove do much useless energy. Warner Brothers (WEA) promoted the use of digital bins and analogue cassette tape as "Digilog" cassettes.

So the EE tape did not die a quick death--it lingered as a bin master tape for a few years in the late 80's, early 90's.

[cabraham]

BASF actually used chrome "EE" tape in half-inch and 1-inch widths as LPR 921 Bin Master tape for the professional duplication market. The master tape that fed duplicator slaves recording cassette pancakes was originally a ferric tape. If the recording of the master were at 7.5 ips, the sound from the master was quite good; but if the master were recorded on ferric tape at 3.75 ips, there was the typical loss of SOL. The chrome 921 Bin Master gave a far superior performance at 3.75 ips in terms of SOL, and the recordings from those masters showed a noticeable improvement in terms of sound quality. The 921 ran in the bin at 300 ips, so wow and flutter and azmuth were not a problem! It was a concept that was beginning to take off until Concept Design developed a digital bin loaded with solid-state memory. The improvement with the digital bin recording onto analogue tape was dramatic; and the tape, both ferric and chrome, could take another 2-3 dB of signal without any increase in distortion because the peaks were much cleaner and free of modulation skirts that drove do much useless energy. Warner Brothers (WEA) promoted the use of digital bins and analogue cassette tape as "Digilog" cassettes.

So the EE tape did not die a quick death--it lingered as a bin master tape for a few years in the late 80's, early 90's.

Ok, for high speed duplicating, w/ 3.75 ips speed, EE would make sense. But azimuth could be an issue. At 3.75 ips, azimuth is critical. Pro machines are likely to be built for fine adjustment of the azimuth angle. I'm sure the angle was calibrated frequently resulting in negligible hf loss due to misalignment. Although it ran at 300 ips, all frequencies get multiplied by 80, since 80*3.75=300. So a 20 kHz signal is translated up to 1.6 MHz. So azimuth loss at 1.6 MHz at 300 ips is equal to that at 20 kHz at 3.75 ips.

The higher speed does not mitigate azimuth misalignment issues. But as I said, the machines are adjusted with that in mind & likely are well aligned. Anyway, we seem to concur that when the speed is low, i.e. 3.75 ips, EE is justifiable, & offers something the ferric tapes cannot offer at such low speed.

[Des-Lab]

Since I haven't done one in ages, maybe I need to perform a full bench test of EE tape with my X-2000R and see how it really does. I know it's absolutely, 100% forgetable at 7 1/2 ips (even a lowly Quantegy 642 would have no trouble keeping up with it, let alone a high end conventional oxide like Quantegy 457 or RMGI LPR-35). I have done only casual tests at 3 3/4's but don't recall the results offhand. I personally doubt these claims and am skeptical that the difference would be sufficient to offset the cost versus half-speed issue.

Look to see this test sometime next week.

[Wilhelm]

Once dialed in correctly for accurate azimuth, a high-speed bin playback head and the slave record heads did not drift; and the high speeds of the heads meant that a tremendous amount of energy was required to misalign the tape from its proper path. Azimuth mislignment was not a problem in high-speed duplication, either for the master tape or the slave tapes.

This was another reason that calibration tapes were generally recorded at higher speeds than their intended playback speed.

In looking over my notes on EE tape, I discovered that one of the solutions EE tapes offered for 4-track tape was the reduction of the low frequency cross-talk in the heads that was a problem at 7.5 ips or 15 ips. Two-track heads had less cross-talk, but the narrow spacing between tracks on a 4-track head created some problems that were more apparent the faster the tape traveled. Reducing the speed to 3.75 ips brought the level of noise to a lower frequency that was less audible, but at the risk of greater azimuth mistracking if the tape guidance was insufficient. The same principle was behind the development of the Unisette which ended up as the Elcassette after the Japanese stole the idea from BASF and developed their own format.

[cabraham]

Since I haven't done one in ages, maybe I need to perform a full bench test of EE tape with my X-2000R and see how it really does. I know it's absolutely, 100% forgetable at 7 1/2 ips (even a lowly Quantegy 642 would have no trouble keeping up with it, let alone a high end conventional oxide like Quantegy 457 or RMGI LPR-35). I have done only casual tests at 3 3/4's but don't recall the results offhand. I personally doubt these claims and am skeptical that the difference would be sufficient to offset the cost versus half-speed issue.

Look to see this test sometime next week.

Thanks in advance. I've been pondering w/ the idea of picking up a tape deck w/ 3.75/7.5 ips capability. I have many tapes from the 70's & 80's that were taped at 3.75 & 7.5 quarter track. My low speed 1/4-track deck died, all I have is a 7.5/15 ips 1/2-track unit.

So I was wondering if I should get an EE type of deck, or just a conventional non-EE unit. If the EE tape is worth it, that would justify it. I await your test. I've heard conflicting reports re EE. You mentioned at 7.5 ips, the EE was "forgettable". Am I to understand that you were not at all impressed? At 7.5 ips, how would Maxell XL-2 (EE) compare with XL-1 (non-EE)? Just wondering. Thanks again.

[Wilhelm]

There is no advantage to an EE tape at speeds above 3.75 ips. There were few EE tapes manufactured and far fewer EE recorders, so it would not be easy finding either a machine or the tape for it. At 7.5 ips the only possible difference between Maxell EE tape and their standard ferric might be slightly lower modulation noise, but only if they calendered the EE tape harder than usual. Since the higher coercivity of the tape would not require harder calendering, that is not likely.

[eclectiktronik]

might be worth making a list here of known recorders with EE feature, for reference purposes.

[Des-Lab]

might be worth making a list here of known recorders with EE feature, for reference purposes.

It wouldn't be a very long list at all, considering that EE didn't show up until the tail end of the consumer R2R era.

Offhand, I know of the following:

Teac: X-20R, X-300R X-700R, X-1000R, X-2000R

Akai: GX-646, GX-747, GX-77.

That list probably covers 90% or more of all the EE enabled decks. I believe that some late model X-10R's *MAY* have had it, but I won't swear by it. There also might have been a Tandberg deck that had it. But again, I'm not sure.

I haven't forgotten about the evaluation. I've been a little tied up this week, but I promise that it is coming soon.

[justin31972]

The Teac X-3R (MK-II) was also capable of recording on EE tape.

[Eminence1963]

It wouldn't be a very long list at all, considering that EE didn't show up until the tail end of the consumer R2R era.

Offhand, I know of the following:

Teac: X-20R, X-300R X-700R, X-1000R, X-2000R

Akai: GX-646, GX-747, GX-77.

That list probably covers 90% or more of all the EE enabled decks. I believe that some late model X-10R's *MAY* have had it, but I won't swear by it. There also might have been a Tandberg deck that had it. But again, I'm not sure.

I haven't forgotten about the evaluation. I've been a little tied up this week, but I promise that it is coming soon.

Still waiting........................................... .......*flame*

[shotwell]

Still waiting........................................... .......*flame*

He's busy playing with some new toys he recently acquired...

BTW, where in Washington are you?

[Eminence1963]

He's busy playing with some new toys he recently acquired...

BTW, where in Washington are you?
Left u a PM on where I live
I know how that goes when I gets a new toy*check*

[Des-Lab]

Testing in progress. Look for my long awaited writeup to be posted later this afternoon once I finish it, write up all my notes, and piece it all together here.

Reports-the way *I* do them-is a time consuming process.

[Des-Lab]

Test report (http://www.tapeheads.net/showthread.php?t=10257)conducted and at last published.

[Skywavebe]

Nice and concise DES,
I don't like the test with tones done only at the 1KHz and below signals. What happen to the results of the much wanted and often talked about high frequency content. Distortion and good tone quality is important but so are the balance of the other frequencies which I think the 3.75IPS is suppose to go up to 18KHz. Now with Teac's rating being tested at -20 dB, of course the results at real use level do not match that at all. That is why I do not use and have not for many years that -20 dB level for Bias setting as it is an incorrect adjustment. It is really clear to be able to demonstrate.
On the level difference between channels, I can tell you that those machines are really hard to get adjusted perfectly for several tapes at the same time. MOST people do NOT use EE tape so the adjustment are optimized with a tape like XL I. The calibration procedure has you going through the EE setting first so as to set the range of bias and level to it's button settings then the single pot adjustments in some cases are made to get the LHII setting to correct position. When I say single pot adjustments- that is where problems come from in trying to gets levels balanced with the different tape than what you started with (EE). Then that means that since the premise is that the LHII (XL I) tape is to be used the most, that the EE setting are adjusted again to perfect the LHII setting so that clients do not complain of level issues. Some people that own the X2000R will never even own a EE tape. There is the problem with this deck. If you have to adjust the EE setting to get the LHII settings correct, you end up in a battle between EE and LHII levels and balances.
Why is this? NOT enough POTs to control all the parameters. Some people wonder Why I like the Z6000 cassette deck- it DOES have all the adjustments.
Anyway, I am sure your evaluation has great merit to those people that use that deck. My post is just to explain what is going on and the cause behind them as well as the headaches that we face to get the machine to calibrate up correctly. The Bias setting on the front only allows a 15% variance and that may not be enough with some tapes that are starting a good amount off the norm. Now you might understand when the Tech asks what tape do you want it calibrated for- he is only wanting one name. Not a list.
If they do not ask this question, they are using what they want or the other alternative.

[Lapis]

Thanks in advance. I've been pondering w/ the idea of picking up a tape deck w/ 3.75/7.5 ips capability. I have many tapes from the 70's & 80's that were taped at 3.75 & 7.5 quarter track. My low speed 1/4-track deck died, all I have is a 7.5/15 ips 1/2-track unit.

So I was wondering if I should get an EE type of deck, or just a conventional non-EE unit. If the EE tape is worth it, that would justify it. I await your test. I've heard conflicting reports re EE. You mentioned at 7.5 ips, the EE was "forgettable". Am I to understand that you were not at all impressed? At 7.5 ips, how would Maxell XL-2 (EE) compare with XL-1 (non-EE)? Just wondering. Thanks again.

Ok, for high speed duplicating, w/ 3.75 ips speed, EE would make sense. But azimuth could be an issue. At 3.75 ips, azimuth is critical. Pro machines are likely to be built for fine adjustment of the azimuth angle. I'm sure the angle was calibrated frequently resulting in negligible hf loss due to misalignment. Although it ran at 300 ips, all frequencies get multiplied by 80, since 80*3.75=300. So a 20 kHz signal is translated up to 1.6 MHz. So azimuth loss at 1.6 MHz at 300 ips is equal to that at 20 kHz at 3.75 ips.

The higher speed does not mitigate azimuth misalignment issues. But as I said, the machines are adjusted with that in mind & likely are well aligned. Anyway, we seem to concur that when the speed is low, i.e. 3.75 ips, EE is justifiable, & offers something the ferric tapes cannot offer at such low speed.

The EE tape type was clearly intended for low speed consumer recording. It was a type 2 tape, equivalent to type 2 cassettes. BASF used a true CrO2 particle, & Maxell & TDK used ferricobalt equivalent (FeCo).

Obviously, EE was never aimed towards the pro/semipro market. For 1 thing, all 3 brands of EE were only offered in 1.0 mil thickness, the choice for home recording. Pro & semipro users bought 1.5 mil thickness. This reduces print through & has less tendency to stretch/break, important at high winding speeds w/ 10.5 in reels.

Also, only the BASF brand of EE tape offered back coating. TDK & Maxell did not offer back coating on their EE tapes, but did on their ferric oxide conventional tapes. The ferric tapes offered back coating as well as the 1.5 mil thickness, clearly aiming for pro use.

All multitrack & high speed (7.5/15/30 ips, half track) mastering decks I've ever seen or heard of did not offer EE capability. All EE decks were low speed (3.75/7.5 ips), quarter track. Again, this tells us that EE was a consumer format.

Still, EE was a good idea. I agree w/ a previous poster that had it been brought out 10 yrs. sooner, it may have had a bigger impact. It did what it claimed. The FeCo or CrO2 tape could accept higher hf levels before saturating, i.e. better hf headroom. On playback, the eq time constants were lower (less treble boost) resulting in higher s/n ratio. Tests confirmed that EE at 3.75 ips could match ferric at 7.5 ips. NAB eq for 7.5 ips was 50 usec, & for 3.75 ips it was 90 usec. EE eq was 35/50 usec for 7.5/3.75 ips resp.

So home recording of LP records for preservation could be done at half the speed. This not only saves tape cost, but head wear is greatly reduced. At twice the speed, the drag force on the head is twice. Also, twice the length of tape passes over the heads at higher speed. So the head wear is 4 times greater at twice the speed. Also, playing times are extended.

The downside to half speed EE recording is that hf loss due to azimuth error is greater at 3.75 ips by 4 times (vs. 7.5 ips). Also, wow & flutter at 3.75 is greater, EE type not being able to correct for these issues. Still, EE provided some substantial benefits. If brought to the market in 1970 (instead of 1980), it would have likely caught on.

At high speeds, ferric oxide is the better choice. At low speeds, CrO2, FeCo, & metal have higher saturation levels, i.e. MRL/MOL. Ferric oxide actually has lower distortion than all others until MOL is reached. The ferric MOL is lower than the others at low speed.

But at high speed the MOL is very well above 0 dB, so that ferric gives lowest distortion levels. Also, hf losses at high speeds are slight w/ ferric, but great at low speeds. EE can do quite well at 7.5 ips, & a little better at 15 ips. But 15 ips is where premium mastering tapes like 3M 250/226, Ampex 456, etc. really shine. At 3.75, these mastering tapes are quite poor, as they are optimized for high speed.

Did this help at all? Comments/questions welcome.


Azimuth is important for all speeds.