Playing with Memorex

As promised, I've begun evaluating various 8 track formulations,
basically to see what could be done with 8 track carts as a recording
medium. Enough with the NudoFraud for now; I'm finding him
increasingly tiresome and dull.

Overall, 8 track as a consumer recording media seems to have much in
common with ferric formula .5 mil open reel tape of the same era in
terms of noise and saturation. I played with a Memorex 90 recently,
but didn't have enough time to do any real bias setting or noise
readings on it. It seemed that the Memorex carts were less "bias
hungry" than Scotch, more like BASF in that respect, gave a bit more
high end when so adjusted, but had NO headroom at all, indicating a
low MOL. Even the cheesy head amps in the Wollensak 8075 easily drove
Memorex to saturation at about a +2 VU, making it a pretty wimpy
oxide. Probably not a great choice for "loud," but I did notice a
rather low noise floor...lower than both Scotch Dynarange and BASF,
probably by about 4 or 5 dB, thus maybe making it better for
classical, jazz or other more ethereal musical mediums than "car
rock." Of course, there's a correlation here...noise floor goes down,
so does the MOL, so in reality you're probably getting about the same
stuff, just at a lower level.

Just for laughs, I crammed in an Ampex 84, and got pretty much what
I'd expected...it likes more bias, and has LOTS of headroom compared
to others, but there's a caveat. Home tape gear in general has pretty
weak kneed head amps, so using a "cold" tape like this entails hitting
the tape harder to get up near saturation, so it's easy to run out of
amplifier before you run into tape saturation. We'll see; as stated,
no metrics yet, but I'll get to that when I have a hankering to
assemble all the test gear again.

Arrived via UPS today: Low speed (3.75/7.5 IPS) capstan motor for my
Ampex...tough to find, but the guy had no use for it at all, so I got
it basically for price of shipping! Using an MRL alignment tape as a
fluxivity standard and using my full track head bridge, I should
easily be able to cut a reasonably good reference and alignment tape
on cart tape. It just takes time...lots of it...and inclination. I
figure just open up a Scotch Dynarange 45, cut it, dial back the reel
motors quite a bit to keep from stretching the tape into cassette
tape, and I should be good to go. And NO, I'm NOT going into the
alignment cartridge business, so don't ask!

dB

There's no reason to go messing around with the bias adjustment on a
good 8-track deck, if it's set to specs the deck will record very
well.

The key to low noise recordings with great high end response- even
with new blanks, is to bulk erase the tape first. Dan Gibson, despite
his other technical shortcomings, did correctly point that out a long
time ago here- and I agree with him 100%.

You are judging sound quality with meters and scopes which only tells
part of the story. It's very possible to have a deck that "specs" out
great on an O-scope but sounds inferior to another deck in back to
back comparisons.

The best way to compare decks and tapes is to listen with headphones
and let your ears do the judging. They don't lie- they are highly
tuned analog instruments more sensitive than any meter. And besides,
that's what you listen with, so your ears are the final arbiter.

You are spending a lot of time messing with Wollensak decks- one look
inside at the motor and belt setup shows that deck to be inferior to
an Akai, Sony, Pioneer, GE, JVC. Even a Radio Shack TR-802/803 would
be a better machine overall in my opinion.

I have listened to over a hundred different model numbers and makes so
far and any deck with specs over 15khz top end is a good bet. I can
hear the difference with my own ears between an Akai 83D spec'd at
14khz top end, and the Akai 80-81-82's that spec 15-17khz top end.
You actually don't even need a meter.

One downfall of changing that bias as you do, for more top end, is
that when there is blank spaces at the ends of home made tapes, when
you run it to the end, it won't uniformly erase it anymore. Once in a
while you want the built in erase feature to work, i.e. if you record
a tape and one song gets cut off at end of track 4, you can go back
and just erase that song fragment and have a neat orderly tape without
a cut off song. If you change that bias and seal up the deck, now you
have to take the cover off and reset it, to custom erase parts of the
tape.

If you had a "playback only" deck, then have at it- tweak the bias and
get the added top end. But with STOCK Akai 82D's reaching 19khz in
test, why bother.

My stock decks with un-tweaked stock bias settings, still sound better
than a CD, with more top end resolution than a CD. Reason being there
are no "holes" in analog tape resolution- the comparable "bit rate" of
analog is atomic and molecular, the actual molecules of iron oxide on
the tape are each individually magnetized. In other words, there is
billions or trillions of iron oxide tape molecules each with individua
sound information, passing the tape head per second- while a CD is
limited to 16 bit words, 44khz. This is one reason why going wider
with tape, and faster speeds, yields more resolution. It's the same
as increasing the bit rate and sampling rate of digital.

If you want a real eye-opener for 8-track cart sound, get an Akai
1800SD reel/8-track combo, and set the speed to "high", it then runs
the 8-track side at 7.5 IPS in the unit. Use an EQ to bump up the
bottom end, and record a few tapes on it. No amount of bias adjusting
can match simply running the tape 2X faster. The results are stunning.
Of course 90 minute blanks then only last 45 minutes.