Since Recording the Masters (RTM) tape manufacturer from France introduced their cassette tape Fox C-60 about 2 years ago, they have been continually improving the formula until getting the quality and specs they were looking for. Today, it has obtained a good standing status among the cassette recordists around the world and it’s recognized as the best cassette tape available in our modern times. ATR and Capture has also introduced their own, but that would be a good theme for another story.
Fox C 60 fans around the world were asking for a longer tape and since the C 90 is kind of standard, RTM heard them and embarked on the development of a new tape length. Well, this is easier said than done because the base film must be thinner and the thinner it goes, the more difficult it’s to develop. Remember; cassette tape is no longer a mainstream media, most of the people involved with this technology are retired or long gone and the materials available today are not of the same quality as it used to be because there’s no volume and “money” into it. After all, this is still a business! During the 80’s this technology used to be an everyday adventure, but not today as our colleagues from National Audio Company has just learned.
Slitter machines used for processing the finished Jumbo tape rolls into the dimensions required are already old, and many has been adapted and modified from other manufacturing product types, like credit cards magnetic strips,etc, into audio tape. Pigments and base films are not widely available as it used to be either. They have to work with what they already have. The advantage RTM has is that they are just adapting their old trusted formulas from BASF open reel tapes into their new cassettes saga. Even though, it has taken them years of development and experimentation in order to obtain what they were looking for. Let’s see if their efforts has been worth it.
The Test
For the evaluation of the Fox C90, we are using some of the best TOL decks available in our studios: the Revox B 215S totally restored by Perry in Virginia and the Nakamichi CR 7, Dragon and ZX 7 all three restored by Willy Hermann. Needless to say that all 10 cassette decks in our collection, as well as the open reel decks, are on top notch condition, serviced, aligned and restored by authorities in the field.
As a comparison reference, we used the long time and popular ferric type 1 tape, the TDK D, graciously submitted by the Tape Heads forum owner himself, Pacific Stereo, who send us a brand new TDK D and Maxell UR for this article. Neither of these are prime tapes from the cassette heyday era, but both has been widely available during all these years and still around in big numbers. Let’s be honest guys: I don’t see any near possibility of producing premium tapes formulas again, like those Maxell XL I-S and TDK AR, not to say almost impossible to see new “chromes” as they used to be, but at least we have 4 companies trying to do their best with the limited resources they have.
As with all samples received before entering the official production run, keep in mind that these are prototypes and some final adjustments could be performed before it hit the shelves. Anyway, we received the Fox C90 loaded in a 5 screws shell, probably from one of today’s scarce C-O manufacturers from Italy. The tape was neatly loaded and the total appearance was good. Again, please remember that those elaborated shells from the past are no longer produced and I believe that there’re only 2 shells (or C-0 as we call it in the duplication business), manufacturers in the world right now: one in China and the other already mentioned, in Italy.
We wound the tape back and forth on the CR 7 deck and it runs totally smooth. The usual noise of high speed tape winding, but nothing serious. We did noticed that the pack was a little thicker compared to the TDK and Maxell tapes, but this was expected due to all the reasons we have already explained in this article concerning machinery, material and pigments availability. The important issue here is that the tape runs smoothly and it doesn’t rub on any shell inner surface.
The Sound
For this article, we teamed up with one of the remaining living authorities of Magnetic Media in the world and former BASF Director of Sales for Professional Products, Mr. Terry O’Kelly which we have had acquaintance since the 80’s when we used to be Ampex and BASF distributors for Puerto Rico, where (another tape legend) Don Morris and Marie Given shared our account. Those were the days when tape pancakes, C-0’s and Norelco Boxes were bought by pallets almost every month!
For this occasion, Terry was in charge of the technicalities, while we took care of the subjective appreciations and came out with a balanced review. I choose a high energy material from Tidal Masters for the first listening test and recorded all the tapes using the same level and same deck. On the CR 7 we push it up to +6dB occasionally for level and sensitivity testing purposes without Dolby to see how far they could go, and these were my impressions during the audition:
Fox C 90:
1- Better Bass overall
2- Forward Mids
3- Wider Soundstage
4- Hissier
5- It did managed the top peak levels on the CR 7 fairly easy
TDK D:
1- Less Bias needed
2- Better Focus
3- Less Hiss
4- Leaner Bass
5- Higher Output overall
Maxell UR:
1- More compatible in sound with the Fox than the TDK.
TDK D still a more refined tape and, for the price you could get it for, still a bargain. With the ample resources that TDK company has and with their ability to buy materials in big volume, it was easier to obtain a better formula. That’s for sure. We also need to consider the time when these tapes, TDK and Maxell, were made against the less than one year old Fox C 90. I have to confess, though, that TDK D was never my favorite then and the units I have were given to me by friends. I was, and still, a strict CRO2 or premium Ferric tape user all the time with thousands of tapes in my collection. I still have enough tape for recording until the end of my days or the cassette demise! Whatever comes first…
When using Dolby B or C, the noise problem stops and the Fox C 90 become a different beast. I recorded a more gentle material, like Jazz for example, with Dolby C and the performance was really good indeed. On the other hand, what really surprised me from the TDK D is the quality this company obtained in such an affordable product. We have to give them that, BUT, and this is a big “BUT”, how much this same tape could be today in 2020? See what I’m saying?
Technicalities by Terrence O’Kelly
COMPATIBILITY–Recorder set up for IEC Reference Tape
| Tape | Sensitivity at 400 Hz(dB) | Sensitivity at 15kHz(dB) | Comment |
| IEC Type I | 0 | 0 | BASF Batch R 723 DG |
| Fox C-90 | -0.3 | +0.4 | |
| Fox C-60 | -0.9 | +0.1 | the samples sent two years ago |
| BASF Extra I C-90 | -0.1 | +0.0 | typical BASF basic ferric |
| BASF LH-Maxima I C-90 | 0.0 | +1.5 | cobalt-enhanced premium ferric |
| Maxell UD C-90 | -0.7 | -0.7 | an old version of Maxell basic ferric |
| TDK D C-60 | -0.8 | +2.0 | an early 1990s version of TDK basic ferric |
ELECTRO-ACOUSTICS–Each Tape at Its Best Settings
| Tape | MOL(dB above reference level of 250 nWb/m at 315 Hz) | Bias Noise compared to IEC I tape (dB) |
| IEC Type I | +2.4 | 0 |
| Fox C-90 | +0.1 | +1.6 |
| Fox C-60 | +1.5 | +1.4 |
| BASF Extra I C-90 | +1.9 | 0 |
| BASF LH-Maxima I C-90 | +3.0 | -1.5 |
| Maxell UD C-90 | +0.1 | +1.5 |
| TDK D C-60 | +2.5 | +0.1 |
The C-90 is using a thinner coating than they are using for the C-60, and that is why the MOL is lower. Low frequency sensitivity, however, is higher for the C-90; so they have learned a few things since the C-60 production of a few years ago. (I tested at 250 nWb/m, so the C-90 MOL is 2.1 dB over the Dolby NR mark.) The test deck is a Nakamichi ZX-7 whose frequency response matches IEC standards up to 10 kHz, with a 2.5 dB rise to 18 kHz.
The compatibility section is to check how likely the tape performs in a deck with fixed settings for an IEC compatible tape. Here the Fox C-90 looks very compatible with only a slight rise in high frequency sensitivity, which will end up sounding “better” to listeners. Dolby NR mistracking will boost the treble slightly, and this will also sound pleasant (so many people encode with Dolby B and then do not decode the tape in order to get the boosted high end.) The C-90Â appears more compatible than the C-60. The Maxell, an old tape from the late 1970s, shows how much more sensitive ferric tapes became over time. The TDK D is the least compatible and appears to be underbiased, suggesting that this tape uses a more advanced oxide closer to the AR series but without cobalt enhancements. This makes sense for a company buying oxide in bulk.
The electro-acoustic chart is based on each tape being adjusted for its best performance on the Nakamichi. The MOL for the Fox C-90 is fairly low, but the same as that for the Maxell UD, which was a very good tape in its time. The other tapes have more comfortable headroom, including the TDK D, more evidence that this “budget ferric” from TDK is using advanced pigment. Noise is what one would expect from each of these tapes. The BASF LH-M used a very refined oxide enhanced with cobalt, so its noise level is an improvement over all the other basic ferric tapes. The TDK D again shows a relatively low noise floor suggesting TDK was using a very good quality oxide for this budget formulation.
The noise for the Fox C-60 and C-90 is the same. There is only so much they can do with the oxide available on the market today. I don’t think they can improve on noise much, even with heavier calendering. MOL can only go up if they: 1) coat C-90 thicker, which they can’t do without creating to big a tape pack; or 2) increase packing density, which runs the risk of a dirtier tape if they don’t cross-link or flaking if they do cross-link the binder resins. A better oxide would help–but no one provides better oxides these days because there is no longer a significant demand.
It appears that RTM has chose the wise path of increasing sensitivity on both the low end and high end to match that for the most common settings used in recorders that do not have user-adjustable calibration. To consumers, that means that setting the meters to a point for recording will show the same point on playback. There is a slight boost in high frequency sensitivity that will sound “good” for many listeners. MOL is satisfactory, and unused headroom is inaudible anyway. The only users who will be disappointed there will be those who like to slam their meters to the max for maximum loudness (usually for today’s music with no dynamic range at all!) Using Dolby B NR should take care of the noise, and those who do not like it and record today’s compressed musical content will not likely notice the noise.
Tape production is full of compromises. RTM is restricted by the availability of a range of oxides, and to me it seems they made the right compromises to satisfy most consumers looking for a reliable C-90 tape. Fox C-90 is a decent basic ferric cassette tape when compared to the best of the past. Compared to what’s available today, it is the best choice on the market right now.
Conclussion
Excellent technical synthesis by Terry on the different tape formulas capabilities and its best performance. It was really nice to see that the technical findings of Mr. O’Kelly in the USA and ours, dealing with the subjective appreciations down in Puerto Rico arrived, more or less, to the same conclusions! It would also be nice to see the measurements of another esteemed colleague from Europe that goes in the Tape Heads forum as Werner. It should be interesting to know about his findings and compare notes against ours. He has a highly informative website with many different tape measurements that could be of great interest to those looking for a more in-deep didactic material. Look for Werner on the Tape Heads website.
With all the tape fever renaissance en vogue, it’s good to know that we are not limited to the use of old NOS tapes with over 30 years old, at a ridiculous selling price. We can enjoy new formulas on fresh tapes available for everyone from RTM, ATR, NAC and Capture. Unfortunately, it has limitations as we no longer could buy a C 90 for $1.95 at the drugstore, but on the other extreme we don’t have the need to pay $8.00 for a 30 years old Maxell XL 1 either. We wish we could have newly developed tapes for the price of 30 years ago, but that’s totally impossible. To make the matters worse, the volume and profits are simply not there. Raw materials are difficult to get. There’s no money in cassette tapes anymore and I understand that this is more a labor of love, devotion and customers satisfaction than money. Believe me. I know.
We have to take off our hats to these companies that insist on manufacturing a commodity product today from a technology long gone. This is a novelty for many and a lifetime passion for others. For how long they could keep up the pace? I don’t know. If there any possibility of having a CRO2 formula in the near future? I don’t know either, but I’m sure that RTM won’t stay idle with their arms crossed. One of these days, fellows, one of these days…
The authors:
Terrence O’Kelly, from Massachusetts, is an authority in the Magnetic Media field and used to be one of the BASF principals during the 80-90’s era directing the only profitable audio division of that company in the USA: BASF Professional Products Division. He’s also an avid technical writer and for many years BASF published his bulletins.
Carlos J Guzman, from Puerto Rico, is a Grammy Winner Mastering Engineer with the biggest tape decks collection in his homeland. He has been dealing with tapes since the age of 10 and has never stopped using tapes and tape recorders since then. Author of many technical articles of Audio, Mortuary Science and Sismology.
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