TDK SD carts...best of both worlds

Today, after doing some chores, I shoved a TDK SD into my Sanyosak and
ran some numbers on it. I'd heard that people find this to be nirvana
in 8 track blanks, so I was curious what it had. I quickly found
out...it's GOOD stuff!

SD is hotter than Scotch 175 by around 2 dB, but is as quiet, yielding
a better signal to noise ratio. It also exhibits superior headroom
than cheaper TDK cousins by far, thus putting it in the likes of Ampex
381 in that regard. Although I could drive SD into nasty distortion
before my record amps crapped out (which I could not do with the high
priced Ampex 389 and Scotch Classic), it was a matter of pegging the
meters to get near that point. Plus, remember, this tape exhibited
surprising sensitivity for a Japanese oxide...moreso than the other
TDKs or Maxell's LN. This puts this tape in the upper half of
desirability based on performance alone, but the coup de gras was its
aforementional speed performance...as flawless as 8 track could ever
be.

The samples of TDK SD-90s I have could, after about 3 or 4 passes to
"limber up," deliver wow and flutter performance that rivals later
cassettes, and gets into RTR territory...a weighted .02%, and an
unweighted .30%! Compare the unweighted measurment to an good Ampex
350/351 transport, which turns in a .25% at 7½ IPS...and that's a pro
grade machine, even today. By far, this is the best cartridge for
serious music, simply based upon that factor. Add the very good
recording characteristics, and you have a winner. Due to its copious
headroom, TDK SD worked very well with Dolby "B", even at higher drive
levels, rivaling Ampex in this regards, and showing no signs of
compression of the top end obvious on TDK D, obviously a much cheaper
oxide. Even without Dolby, SD is more "listenable" due to its good
noise floor, assuming you hit the tape hard enough to provide it. Of
course, listening in the car, this factor isn't as important, but at
home, it certainly is, especially on dynamically diverse program
material. For most trash rock or pop, this tape's characteristics
would largely be wasted, but on more esoteric material, it shines
brightly.

A problem is scarcity. This was about the toughest tape to get off of
sleazeBay, even moreso than the Scotch Classics I got. Fortunately,
they were tucked away in a "multi-brand" lot, and I guess those who
look for this type didn't see it in the description, but it was in the
picture! I've only seen SD offered alone in one other auction since I
started fooling around with 8 track, so its rarity would be a problem.
It's worth tracking down, however, if you have a high end recorder and
player. Looking at the numbers, however, Ampex 389 and Scotch Classic
outperform it handily IF the recorder can take advantage of it, but SD
offers a nice balance...normal bias requirements, nice top end out to
14 KHz (-3 dB), with a hot sensitivity and high MOL.

So, the comparisons between "D" cartridges and these is similar to the
best and worst of TDK cassettes. TDK D is one of the worst of the
Type Is in many performance areas, while their Type IIs top of the
line formulation's quite good...maybe not as good as some of the
Maxells, but quite good. It's a shame Maxell ceased making high
quality Type I tape; they were the best of all of them, and the
remaining UR line is on a par with TDK D, although somewhat better.

Conclusion: If you can find it, get it, if you're a serious
recordist. If you can't find it, Ampex 389 and Scotch Classic will
outperform the SD, but only in tape performance. NOTHING offers as
good a speed performance as these cartridges I've tested so far.

dB

I think this is the variety of TDK I was talking about. A very nice
shiny brown oxide tape, with a wide rubber pinch roller and, of course,
outstanding construction
On the Akai it really stood head and shoulders above other tapes, I
recorded the alan parsons quad version of floyds' dark side for someone
using this tape. It is an extremely rare variety but worth the xtra $ if
you just HAVE to have something special in 8 format. (my eyes could
easily roll here lol)
While I like memorex regular and the scotch (but I don't like the scotch
cart design, how do you take those damn things apart? flat packs were
easier!)
this was the best by far to my quite sensitive ears
Perfect for dynamic, well recorded music. Anything else would be a waste
of its stellar quality.