More about alignment and Wollensaks

Recently, I spooled up my 3.75 IPS NAB alignment tape from MRL onto an
8 track cart spool and ran it through my Wollensak 8075. Now, with
reference level properly set at 185 nWb/m and the head aligned
PROPERLY, I ran some more freq runs on a few standard ferric oxide
carts, and got some idea of what the real frequency response of this
unit is. Not surprisingly, playback of -7 VU reference tones was
pretty flat up to about 14 KHz, no big surprise, with the -3 dB point
showing up just over 17 KHz and "usable" (-8 dB) response up to 20
KHz...pretty respectable and on a par with good two head RTRs of the
same era. In order to get this, I had to bypass the FM 19 KHz pilot
trap in the 8075, however...no bid deal, since Dolby FM has been dead
for what, 25 years, and recording FM onto 8 track isn't a really big
deal for me. Of course, gap spacing on dual duty heads is
automatically compromised, since it has to be a median between optimal
recording (wide) and playback (narrow,) so it's conceivable that a
straight player, IF it had a head with gaps optimized toward playback,
would exceed this. However, most 8 track players were "cheapies," so
I don't think there's any higher "fi" from a straight playback deck
than from a recorder.

Now that I have adjustable bias on this thing, I've been able to spec
out some tapes. Not wanting to go into all the testing regimen I
applied, I'll just give the results, while stating that my goal was to
attain the best possible frequency response while maintaining an MOL
(5% third harmonic distortion point) around a +3 VU. Surprise! The
winner wasn't Scotch or Ampex or even any of the Japanese tapes...it
was Memorex! There's a caveat here, however, in that Memorex isn't as
"hot" a tape as either of the aforementioned; Ampex seems to win that
category going away, as it turned in a playback 2 dB hotter than any
other of the carts I've tested so far, thus increasing signal-to-noise
ratio by the same figure, theoretically. The Memorex 80s I tested
also tended to show more noise up in the high spectra, mostly I assume
because of its lower sensitivity. Anyway, at a -10 VU, I was able to
get an easy 13 KHz at -3 VU on record/playback, and it seemed to take
more signal at 20 KHz, even with the compromised gap a combo head like
this presents.

However, there's a problem with the Memorex carts themselves, as they
tend to be highly prone to wow. They use a modification of GRT's "K
wrap," where the tape goes to the rear of the cart and wraps around a
post before spooling into the headend of the reel. I fiddled and
farted with the cart (which was "new old stock") and found that
putting a minute amount of PTFE on the pinch roller and spool posts
eliminated some, but not all of it. Next, to the pads. I equip all
my carts with the Win-Gib pads, as close as you can come to the tape
pressure of the originals. I took out the pads, used some of
Winnard's knowledge in "curing" the foam by applying heat from a heat
gun, and sure enough, it DOES increase the pad pressure a couple of
grams. Interestingly, when reassembled, the wow was gone, not much of
a price to pay for what is probably the correct pad pressure to begin
with. I can only theorize that the elasticity of the pads prior to
curing was acting in concert with drag in the cartridge to start a
sort of oscillation with the tape. You can see a similar effect when
idler arms on some RTR machines are too weak, or tape back tension is
similarly too low...the idler arm(s) will wag up and down, instead of
staying where they should. Whether this is what's really ocurring is
a subject for conjecture. Not having a clear window to watch (or any
access to see anything anyway,) I can't really say for sure.

A word about head pressu LOWER is BETTER as long as the oxide is
in intimate contact with the head's gap(s). Many times, in an effort
to provide more stable high frequency response from a worn head,
people will crank up pad pressure (or reel tension on three motor
machines). This might give temporary relief, but ends up just wearing
the heads all that much quicker. Iron oxide is, of course, an
abrasive, and heads will wear regardless of how much lubrication was
added to the oxide binder during manufacture. Ampex did a published
test back in the 354 era about this, and found that wear increased
linearly with increase in tape tension, but increased almost
exponentially with an increase in tape speed. I noted this on many
Ampexes over the years; those used at 7.5 or 15 kept their head
bridges almost forever before lapping, while the 30 IPS machines wore
them out rather quickly. Another "bad" thing, especially on 8 tracks
and cassettes: "dry head cleaner" cartridges. Might as well run 1500
grit wet or dry across them! Use 96% isopropylene and a
Q-tip...nothing much works better on either the head or the capstan.

As mentioned earlier, most commercially duped carts produced for big
labels (Columbia, RCA, WEA) were almost dead on for azimuth alignment,
but there were some real corkers! I have a Johnny Rivers cart on
Liberty that's horridly askew on azimuth, and a GRT release of Three
Dog Night's "Golden Biscuits" album that has some wicked horrible
track height problems, AND some added bass that doesn't belong there.
There was another example of an Ampex product of the same release in a
"thrift store grab bag" I got, and it was dead on in both planes.
Funniest one was an Earl Grant bootleg someone cranked out on a home
recorder...both azimuth AND track placement were way off, and the
speed was almost a half steps worth high! Thus, I'd figure IF you
have a major label cart with a lot of highs in it, you CAN "fudge" the
alignment without an alignment tape and be comfortably close to being
laboratory accurate.

Enough for now! I have to go try to fit an Ampex ¼" 8 track
duplicator head into a 351 head bridge. Could I be making commercial
quality frauds to compete with Nudo soon?? Nawwwwwwww....

dB

Bob,
Don't think from the lack of responses that no one finds this fascinating. I
do.
And it sure beats the hell out of the fascination with off topic crap.
Keep us posted on your findings,
Dan 1.5

Subject: More about alignment and Wollensaks
From: DeserTBoB

Recently, I spooled up my 3.75 IPS NAB alignment tape from MRL onto an
8 track cart spool and ran it through my Wollensak 8075. Now, with
reference level properly set at 185 nWb/m and the head aligned
PROPERLY, I ran some more freq runs on a few standard ferric oxide
carts, and got some idea of what the real frequency response of this
unit is. Not surprisingly, playback of -7 VU reference tones was
pretty flat up to about 14 KHz, no big surprise, with the -3 dB point
showing up just over 17 KHz and "usable" (-8 dB) response up to 20
KHz...pretty respectable and on a par with good two head RTRs of the
same era. In order to get this, I had to bypass the FM 19 KHz pilot
trap in the 8075, however...no bid deal, since Dolby FM has been dead
for what, 25 years, and recording FM onto 8 track isn't a really big
deal for me. Of course, gap spacing on dual duty heads is
automatically compromised, since it has to be a median between optimal
recording (wide) and playback (narrow,) so it's conceivable that a
straight player, IF it had a head with gaps optimized toward playback,
would exceed this. However, most 8 track players were "cheapies," so
I don't think there's any higher "fi" from a straight playback deck
than from a recorder.

Now that I have adjustable bias on this thing, I've been able to spec
out some tapes. Not wanting to go into all the testing regimen I
applied, I'll just give the results, while stating that my goal was to
attain the best possible frequency response while maintaining an MOL
(5% third harmonic distortion point) around a +3 VU. Surprise! The
winner wasn't Scotch or Ampex or even any of the Japanese tapes...it
was Memorex! There's a caveat here, however, in that Memorex isn't as
"hot" a tape as either of the aforementioned; Ampex seems to win that
category going away, as it turned in a playback 2 dB hotter than any
other of the carts I've tested so far, thus increasing signal-to-noise
ratio by the same figure, theoretically. The Memorex 80s I tested
also tended to show more noise up in the high spectra, mostly I assume
because of its lower sensitivity. Anyway, at a -10 VU, I was able to
get an easy 13 KHz at -3 VU on record/playback, and it seemed to take
more signal at 20 KHz, even with the compromised gap a combo head like
this presents.

However, there's a problem with the Memorex carts themselves, as they
tend to be highly prone to wow. They use a modification of GRT's "K
wrap," where the tape goes to the rear of the cart and wraps around a
post before spooling into the headend of the reel. I fiddled and
farted with the cart (which was "new old stock") and found that
putting a minute amount of PTFE on the pinch roller and spool posts
eliminated some, but not all of it. Next, to the pads. I equip all
my carts with the Win-Gib pads, as close as you can come to the tape
pressure of the originals. I took out the pads, used some of
Winnard's knowledge in "curing" the foam by applying heat from a heat
gun, and sure enough, it DOES increase the pad pressure a couple of
grams. Interestingly, when reassembled, the wow was gone, not much of
a price to pay for what is probably the correct pad pressure to begin
with. I can only theorize that the elasticity of the pads prior to
curing was acting in concert with drag in the cartridge to start a
sort of oscillation with the tape. You can see a similar effect when
idler arms on some RTR machines are too weak, or tape back tension is
similarly too low...the idler arm(s) will wag up and down, instead of
staying where they should. Whether this is what's really ocurring is
a subject for conjecture. Not having a clear window to watch (or any
access to see anything anyway,) I can't really say for sure.

A word about head pressu LOWER is BETTER as long as the oxide is
in intimate contact with the head's gap(s). Many times, in an effort
to provide more stable high frequency response from a worn head,
people will crank up pad pressure (or reel tension on three motor
machines). This might give temporary relief, but ends up just wearing
the heads all that much quicker. Iron oxide is, of course, an
abrasive, and heads will wear regardless of how much lubrication was
added to the oxide binder during manufacture. Ampex did a published
test back in the 354 era about this, and found that wear increased
linearly with increase in tape tension, but increased almost
exponentially with an increase in tape speed. I noted this on many
Ampexes over the years; those used at 7.5 or 15 kept their head
bridges almost forever before lapping, while the 30 IPS machines wore
them out rather quickly. Another "bad" thing, especially on 8 tracks
and cassettes: "dry head cleaner" cartridges. Might as well run 1500
grit wet or dry across them! Use 96% isopropylene and a
Q-tip...nothing much works better on either the head or the capstan.

As mentioned earlier, most commercially duped carts produced for big
labels (Columbia, RCA, WEA) were almost dead on for azimuth alignment,
but there were some real corkers! I have a Johnny Rivers cart on
Liberty that's horridly askew on azimuth, and a GRT release of Three
Dog Night's "Golden Biscuits" album that has some wicked horrible
track height problems, AND some added bass that doesn't belong there.
There was another example of an Ampex product of the same release in a
"thrift store grab bag" I got, and it was dead on in both planes.
Funniest one was an Earl Grant bootleg someone cranked out on a home
recorder...both azimuth AND track placement were way off, and the
speed was almost a half steps worth high! Thus, I'd figure IF you
have a major label cart with a lot of highs in it, you CAN "fudge" the
alignment without an alignment tape and be comfortably close to being
laboratory accurate.

Enough for now! I have to go try to fit an Ampex ¼" 8 track
duplicator head into a 351 head bridge. Could I be making commercial
quality frauds to compete with Nudo soon?? Nawwwwwwww....

dB

On 23 Oct 2004 02:50:24 GMT, (Danspeakin) wrote:

Bob,
Don't think from the lack of responses that no one finds this fascinating. I
do.
And it sure beats the hell out of the fascination with off topic crap. snip

It's a way to keep busy while recovering from a bout with viral
pneumonia...LOL. Interesting for me, though, was that 8 track was a
lot BETTER than it had a common reputation for back in the late '70s.
Now that I have an 8 track deck equipped with Dolby "B," I can do
side-by-side comparisons with Type I cassettes, something that was
never done in the audio press of that era. Most of the mags back then
dismissed 8 track as a cheesy car format, but took cassette quite
seriously, most probably with proddings from Philips, who was making a
mint off of royalty fees.

I was steered to these Wollensaks due to a glowing review posted on
8trackheaven.com, so I got a couple models on the cheap and decided to
use my magnetic tape recording knowledge to do some real investigation
into its technical capabilities, rather than the usual subjective
blurbs. Yes, the pinch roller setup on 8 track sucks VERY hard, and
yes, they do jam and have drag problems for various reasons. I cannot
EVER remember having disassemble a cassette to repair it...ever. With
8 track, it becomes a career move, especially seeing how these things
are at LEAST 20 years old by now, and the splices on most are going
the way of all splicing tape...apart! However, with a little due care
and fixing, they play well enough (most of them, anyway) to be
regarded as a "high enough fidelity" medium, much as was 3¾ IPS RTR
commercial releases of the same era.

What's great about 8 track is one is able to amass a LARGE library of
"classic rock," pop vocalists and other, more obscure genres for VERY
little money, and, if your luck holds out, they'll sound pretty good
on good equipment. As a car format, though, 8 track lost out to
cassette for VERY good reasons. Those big old vinyl covered 8 track
boxes were HUGE, filling the back seat of the average hatchback of the
era if one wanted a good selection of music for which to go on a road
trip. Sonically, however, 8 track, when all's well inside the
cartridge, yield about the same results as 3¾ IPS cassettes did on
Type I oxides back before Philips (and Sony) lowered the boom on two
speed deck makers in the early '80s. Of course, these two corporate
giants had a BIG stake in replacing cassette with CD, which we're
seeing now, so any notable improvement in cassette by upping the tape
speed was surely a threat.

After some more tape testing, I'm going to do some work on a couple of
8 track car decks I collected, also "on the cheap"...a Panasonic
AM/FM/8 "cheapie" model that is surprisingly robust, if underpowered,
and a Sanyo "AudioSpec" with a lot of goodies on it. Funny how I've
NEVER found a car 8 track deck with Dolby "B" on it...possibly Sanyo
did make one, but I haven't found it yet.

To be continued!

dB

"Danspeakin" wrote in message
...
Bob,
Don't think from the lack of responses that no one finds this
fascinating. I
do.
And it sure beats the hell out of the fascination with off topic crap.
Keep us posted on your findings,
Dan 1.5


Cool, my server didn't post the original message, I'm glad you did. It
was a great post.


winnard

Bob,

I think you are stretching things quite a bit there, again going by
your meter readings instead of common sense.

My Akai 1800SD RTR has a top end of 23,000 khz at 7.5 IPS speed
setting- so to say an 8-track cart is "comparable" is downright
misleading.

Now, I also have a question, as in your previous posts, you were
stating how an 8-track is more or less "maxed out" at 10,000 khz. Now,
all of a sudden, you're hitting 20,000 khz with ease. About 2 weeks
after your previous post.

You appear to be on one heck of a learning curve. i.e. STEEP learning
curve.

Take 2 or 3 decks and hook them all into one receiver amp. Play the
SAME RECORDING in each deck, and move that tape from deck to deck.
Use headphones in your tests. The results will be quite revealing as
to which deck sounds best.

You'll find that a Wollensak will come up inferior to an Akai,
Pioneer, Sony, Telex, or Fisher. It will be an easy comparison as
these other decks sound WAY better than a Wollensak.

Now, look INSIDE the Wollensak vs. Akai, the Akai is built much
better- and the Akai doesn't have small levers that BREAK OFF as
controls.

The drive belt on a Wollensak 8050 is constantly rubbing on the belt
guides, creating wow/flutter. Models after the 8050 from Wollensak,
have a wimpy small DC Motor that has tons of wow/flutter.

I have taken testimony from guys who bought Wollensak decks BRAND NEW
and returned them due to wow/flutter problems in the 1970's- that's
how BAD they are.

I had a Wollensak 8055 deck that had terrible wow/flutter and got rid
of it. I have (2) 8050's now and they collect dust- a Telex or Akai
simply kills Wollensak in sound reproduction.

DeserTBoB wrote in message . ..

Bob, you said this:

"As mentioned earlier, most commercially duped carts produced for big
labels (Columbia, RCA, WEA) were almost dead on for azimuth alignment,
but there were some real corkers! I have a Johnny Rivers cart on
Liberty that's horridly askew on azimuth, and a GRT release of Three
Dog Night's "Golden Biscuits" album that has some wicked horrible
track height problems, AND some added bass that doesn't belong there.
There was another example of an Ampex product of the same release in a
"thrift store grab bag" I got, and it was dead on in both planes.
Funniest one was an Earl Grant bootleg someone cranked out on a home
recorder...both azimuth AND track placement were way off, and the
speed was almost a half steps worth high! Thus, I'd figure IF you
have a major label cart with a lot of highs in it, you CAN "fudge" the
alignment without an alignment tape and be comfortably close to being
laboratory accurate."



Well, THAT'S EXACTLY WHAT I SAID, WITH MY THREAD ABOUT SETTING TAPE
HEAD ADJUSTMENT WITH the BOSTON SELF TITLED Columbia cart.

Gee, your mind sure changed quick, in what, about a week ?? You are
starting to remind me of a parrot.

repeat: You can set head alignment with any good Columbia cart and be
within a smidgen of dead nuts on- or most likely perfectly aligned.

The BEST tape head setting is the one that plays ALL you carts with
minimal crosstalk. (compromise)

The ultimate option is, A DECK WITH EXTERNALLY ADJUSTABLE TAPE HEAD,
"AND" and AC motor drive for the capstan.

And I found one. It's based on the JVC design with the round belt. One
awesome deck and a holy grail of 8-tracking if ever there was one. And
it doesn't record so no recording-relating problems to deal with.

DeserTBoB wrote in message . ..
On 23 Oct 2004 02:50:24 GMT, (Danspeakin) wrote:
What's great about 8 track is one is able to amass a LARGE library of
"classic rock," pop vocalists and other, more obscure genres for VERY
little money, and, if your luck holds out, they'll sound pretty good
on good equipment. As a car format, though, 8 track lost out to
cassette for VERY good reasons. Those big old vinyl covered 8 track
boxes were HUGE, filling the back seat of the average hatchback of the
era if one wanted a good selection of music for which to go on a road
trip. Sonically, however, 8 track, when all's well inside the
cartridge, yield about the same results as 3¾ IPS cassettes did on
Type I oxides back before Philips (and Sony) lowered the boom on two
speed deck makers in the early '80s. Of course, these two corporate
giants had a BIG stake in replacing cassette with CD, which we're
seeing now, so any notable improvement in cassette by upping the tape
speed was surely a threat.




Bob,

I disagree- a 3.75 IPS cassette with METAL tape will sound better than
an 8-track with standard bias iron oxide tape. Reason- the metal tape
is more sensitive, and at 3.75 IPS the tape speed matches an 8-track.
The track widths for cassette and 8-track are the same, the only thing
that made 8-track BETTER was it's faster speed of 3.75 IPS when
compared to the standard cassette 1-7/8" speed.

If you run across a cassette deck that runs at 3.75" that is a killer
piece of equipment, as you can get high quality metal and chrome tapes
for it and run it that fast speed- and you can rewind it- which you
can't do with an 8-track.

8-track blanks were never made with metal or chrome tape.

DeserTBoB wrote in message . ..
"However, there's a problem with the Memorex carts themselves, as they
tend to be highly prone to wow. They use a modification of GRT's "K
wrap," where the tape goes to the rear of the cart and wraps around a
post before spooling into the headend of the reel. I fiddled and
farted with the cart (which was "new old stock") and found that
putting a minute amount of PTFE on the pinch roller and spool posts
eliminated some, but not all of it. Next, to the pads. I equip all
my carts with the Win-Gib pads, as close as you can come to the tape
pressure of the originals. I took out the pads, used some of
Winnard's knowledge in "curing" the foam by applying heat from a heat
gun, and sure enough, it DOES increase the pad pressure a couple of
grams. Interestingly, when reassembled, the wow was gone, not much of
a price to pay for what is probably the correct pad pressure to begin
with. I can only theorize that the elasticity of the pads prior to
curing was acting in concert with drag in the cartridge to start a
sort of oscillation with the tape. You can see a similar effect when
idler arms on some RTR machines are too weak, or tape back tension is
similarly too low...the idler arm(s) will wag up and down, instead of
staying where they should. Whether this is what's really ocurring is
a subject for conjecture. Not having a clear window to watch (or any
access to see anything anyway,) I can't really say for sure."


You leave out an important fact here- NOT ALL TAPE DECKS insert the
tape head an equal distance into the cart. AKAI decks extend the tape
head far into the cartridge while playing, while other decks go in
hardly at all.

Some tapes will play in an Akai 80-81-82 deck WITH NO PADS AT ALL,
just blank spots where the pads should be- try it. That's cuz the
tape head extends so far in, there is often enough tape pressure on
head with no pads at all.

You can't set cart pad pressure to one common spec, as it will BE
DIFFERENT FOR EVERY DECK you play it in- depending on where the tape
head is situated in/out.

WOW/FLUTTER- saying a MEMOREX tape has more "wow" can be misleading-
ANY AND EVERY 8-track cart will gain from lubing the reel post inside
and pinchroller post. You should also LIGHTLY lube the "wear ring"
that is visible under the reel on the cart bottom half, this ring is
caused by the outer edge of the reel digging into the cart base- look
closely you'll see it. Put a dab of lube on that groove. The
pinchroller itself should be cleaned with alcohol, as graphite builds
up on it and they begin to slip. Worn pinchrollers should be replaced.

I agree you'll find a SMALLER thickness pad will work better in MOST
decks. If you fill the cavity with a dense pad, Win-Gib or home made,
the pad presses too hard on the tape head in some decks.

Common packing foam is perfect for making your own pads- it only has
to push the tape lightly against the tape head, not hammer against it.

Another point- reel to reel players such as my Akais don't use pads at
all- they merely pull the tape against the tape head and guide it.
But that's a different format.

BLANKS- you wanna eye opener ?? test some CERTRON blanks. You will be
surprised.