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As to subsequent viewings, I have 3 copies in the film library, but Vault #160/10-4 is the most recent updating off-satellite from TCM, and this is an "Edited by Schmidt" version with a number of minutes snipped out of the apes sequence, which after you've seen once or twice becomes unbearably tedious. I plan to get the dvd which will obsolete all tape copies as they always do.

I'd personally rather see 2001 at home on dvd than watch a faded, reddish scratchy 70mm print. But that's just me, of cuss.

For new 70mm prints, my vote as a practical matter would be I think you are all better off with DTS stereo. For a mag print to be better than this -- and it IS possible, but not probable -- there are certain requirements.

1) Each reel of the new print has to have had the striping properly done and then recorded properly from the mag sound master... a process requiring careful, individualized attention by an expert. Given this, then

2) You must have a good system in place in the 70mm booth to play the print back on. My opinion is that ONLY a Dolby mag preamp or a CUSTOM-BUILT mag preamp system such as I have done will give good results. [If you are so unfortunate as to have Century 70/35 transistor garbage in your booth you are in BIG trouble.]

3) And there is the issue of the expensive mag head in the penthouse wearing out fast -- lasting only 2 or 3 shows? geez. that's not much.

In the beginning back in 1976, Dolby actually didn't really want to produce a mag preamp unit, but was forced to design and manufacture small runs of the MPU- units because the theater mag systems were so awful. There were only two good ones: the original 70/35 system produced by Ampex [of which I believe few survive today] and the Simplex XL system... and both of these to some extent suffer from possible tube noise in their preamp stages. But either of these, if tweaked up properly had the POTENTIAL for pretty-good, if not excellent mag sound. Unfortunately in the typical theatre the systems were NOT properly maintained as the exhibitors wouldn't spend the money.

Thus, this led to the Dolby preamp as the only practicable remedy in the field.

It is also a fact that IF and GIVEN a custom-built mag preamp system, 4-track mag can outperform Dolby stereo on the bi-lateral optical tracks, even with the A-chain NR system. And definitely in 70mm, that's a given. But I believe that very few of you working in the field today will actually have had this sort of hands-on experience. And to the best of my knowledge 4-track mag prints haven't been done for many years.

Yet, a superlative custom mag preamp system CAN BE BUILT and the cost of components isn't all that bad. But it's a lot of labor to carefuly hand-wire it all together.

During the approx. 1960-1976 period, before the Dolby system with Star Wars came out [and Fox FORCED theatres to have it installed to get Star Wars after it became such a big hit] many features WERE produced with a stereo mix on the mag sound master even though most release prints were in mono optical. A handful of prints were striped and recorded in 4-track mag and these were seen in the major markets only; such as in LA and Radio City Music Hall in NYC where I guess for sure the system was maintained, altho I've never been there. [I'm afraid to go to New York!]

It is due to this that we have today so many of these great films in stereo on the AMC, TCM and FMC satellite channels; and such wonderful things as the DVD release of "The Time Machine."

2001 is now showing at the Curzon Mayfair in London, UK. The print is 70mm 6 track mag with SR noise reduction. There is no censor on the beginning of the feature so as to allow the overture to be played with the house tabs closed.

All the best

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I think you are being a bit over the top there. Which version of the Dolby mag pre-amp are you using as the standard? The 92?, 92-2, 92-3, 92-4 or the latest, 92C?

Also the Simplex 6-4-1 mag system was a bit hissy if memory serves...Germainium transistors, as I recall.

Teccon also manufactured mag pre-amps? Ever tried one? They made them for use with their mag heads. The 80000 series were stand alone. They also made special card that fit the Dolby MPU card cage. It had two level and EQ settigns so one could have one set up for pre-1983 and one post-1983 standards or one for 24fps and the other for 60fps.

Recently Panastereo has come out with new mag preamps (Two different units, actually). Ray Derrick is a bit of an analog nut. Are you ready to rule out his preamps or have you used them and determined they are not up to Dolby standards?

To sum things up...sure Dolby pre-amps are good and a worthy standard by which others should be judged (the 92C sets up wonderfully for either 35 or 70mm) but they certainly are not the only ones to consider.

Oh and on 35mm magnetic....there is no doubt that it CAN sound superior to optical, it often suffered from inferior preamp as you have noted, inferior mag heads and the god awful 12KHz tone on the surrounds. If it were produced a decade ago with Teccon mag heads available, Dolby preamps (or others even) and Dolby SR noise reduction...sure it would stomp all over optical but that isn't how it was originally presented. I have run 4-track on faily high-end systems (using both Dolby and Teccon pre-amps) and it wasn't a perfect system but certainly better than optical for its day. An old 4-track vs a current optical with SR...the Optical SR would be judged to be superior, in my opinion, by the vast majortiy in all respects except descrete channels.

Steve

I've been retired for many years [for more on me, see [WHO?] post in film-yak] so what I am speaking of here is somewhat ancient history, and no, I do not have first-hand experience with the preamps you mentioned but no doubt they are excellent. Possibly I could build up something equally good, but there is no need, and I am emphatically retired! If you have a GOOD wheel, no need to re-invent.

The Simplex 6-4-1 system we [I] are speaking of is 100% tubes, circa 1955+ approx. as was the Ampex. These were the ONLY good mag systems, all the rest were absolute GARBAGE, and horribly overpriced garbage at that. Of course the Altec speaker systems had great potential, but it was like a racehorse trying to pull a donkey cart with a flat wheel.

Theatre equipment mfrs. wanted cheap stuff they could sell at high prices and just never seemed to get in touch with the right people who could have designed and given them something better. Never would you find any of the theatre junk at the studios, where practically everything was custom-built. That's why 2001 and many other great films could sound so good!

It may well be that only today is the full potential being realized, based on what I hear at home off-satellite, and especially dvd.

There was no good transistor sound anywhere until McIntosh Labs came out with their solid-state equipment; then gradually other equipment improved but it took Years.

[McI is what I use exclusively at home; it's been running 14 hours a day for 25+ years now + Voice of the Theatre.] Dolby Labs was FIRST to produce good solid-state systems for theatres, and they only did the front end.

Power amps had to come from elsewhere. Of course today good amp power is plentiful and cheap. McIntosh eventually discontinued the amplifier clinics when the competitive gear finally caught up and nearly everything was "a straight wire with gain."

One of my little specialties years ago was producing optical sound reproduction which was so good people thought they were listening to mag. Custom-built. That was the only way. Some optical tracks wre amazingly good. One of my favorite test reels is #1 of "Where Eagles Dare," mainly the overture.

Another old trick: if you had L-C-R speakers on stage, feed mono signal thru all 3.

j.

What exactly do you mean by custom-built optical sound reproduction? Pre-amps? Or more than that?

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Anything is possible with the CP-200. As to L,C, R on mono...I have never liked it! I find that it makes dialogue muddy. There was a period in the '80s and early '90s where on 70mm some films would have "draped dialogue" such that it was on all three channels with L and R at reduced levels. Again, this made the dialogue worse in most cases since if you are near the left side of he screen...it pulled the dialogue to the left even if the actor was on the right.

Steve

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I suppose if the screen was really wide, it might make things better for people on the extreme left and right. The screen I tried it with was about 50 feet wide.

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When the switch is thrown to "Proj 1 and remote" several relays are switched which feed the Dolby optical preamp directly to the CP200 output and connects the power amp inputs together. Everything gets sort of connected to everything, including the non-sync 1 signal, and the mag preamp outputs. The relays also removes power from some PC boards, but not all- the optical preamp, the non-sync and (if running mag) the mag input PC boards still need to be working. A simple 2-relay circurt with a resistor and cap will allow c/o's.

I don't think proj 3 or 4 (if the theater had them) would work. If I remember, a LED would blink, reminding you the unit was in emergency mode (as if you would forget!) Again, a resistor and cap setup would provide the blink. Problem was, you could hear a "tick" in the sound as it charged and discharged during quiet scenes.