Film-Tech Forum ARCHIVE: Perspect-A-Card

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Posted by Steve Guttag (Member # 268) on 10-28-2008, 04:27 PM:

Hey, does anyone know if the Perspect-A-Card by "Cineman" still exists or can be had? Does anyone have a current email address for the person/company that made it?

I'm looking for 2 or 3 of them.

Steve

Posted by Gordon McLeod (Member # 33) on 10-28-2008, 05:09 PM:

I beleive that was Dion Hansen in the UK ex Dolby

Posted by Pete Naples (Member # 761) on 10-28-2008, 05:27 PM:

Steve,

Gordon is correct.

Try dion@cinemanuk.com

Posted by Frank Angel (Member # 248) on 10-28-2008, 06:13 PM:

Steve, if you are going to have a few of these built, let me know because I will try to get the powers that we need to have PerspectaSound capability. Let me know if it works out & maybe we can order them jointly.

Thanks

Posted by Stephen Furley (Member # 1277) on 10-29-2008, 08:03 AM:

Dion is certainly still around, I spoke to him at Bradford during the Widescreen Weekend. I think the cards were built to order, I had to wait a few weeks for mine to be built.

My card has been in the US for sometime now, I lent it to somebody and haven't had any cause to use it since, so I haven't brought it back. The person I lent it to had problems getting it to work in a modified CP-50; It worked fine for me the three times I used it. It's not clear whether the card has developed a fault, or something about the modified processor didn't like it. Dion did say he culd test and repiar if there was a problem with it.

If anybody is interested in trying my card I could ask the person who has it to send it to them; I'm still in touch with him.

Posted by Steve Guttag (Member # 268) on 10-29-2008, 08:21 AM:

I've only ever used it in a CP200...worked like a charm. The "Surround" feature will work (though the early cards had an incorrect part stuffed)...however, it does not have the necessary delay to avoid a horrible reverberation effect in a large room....and...probably more importantly...Perspecta films didn't have surrounds.

The problem with the CP50 will be the logic it uses and what one will need to do to make the signal path work. You MUST have the NR off or bypass the NR cards. Perspecta depends on the LF tones to pass through. Having even Type-A NR on will so severely attenuate those tones as to render the card inoperative (or locked into mono). You also need to not have any bass-extension (for obvious reasons) and you must also have stereo playback (again obvious). I'm not sure the CP50 will easily allow one to get the logic lines the way they need to be and allow the signal to flow.

Steve

Posted by Frank Angel (Member # 248) on 10-29-2008, 08:46 AM:

What about the Panastereo -- I should have no problem there, right?

We do have and external dbx Subbass Enhancement processor that generates half of all frequences below 100hz from L & R (I think that's Hz start frequence) and mixes them back into the L,R, and LFE or just L & R, user choice. That can easily be turned off.

Posted by Stephen Furley (Member # 1277) on 10-29-2008, 09:16 AM:

I've only used it in CP-55 and 65; Dion has used it in CP-200 at NFT and Bradford, all without problems. I can't remember exactly what the problem with the CP-50 was, and I don't know how the processor had been 'modified'.

I'm on my way to Bradford again at the moment, should have been tere about half an hour ago, and we're probably still about 40 minutes away; still got to stop at Leeds first.

If anybody wants to try my card it's in New York, state, not city.

Posted by Gordon McLeod (Member # 33) on 10-29-2008, 11:25 AM:

I seem to remember that Chace in the US also made a perspecta card
To use a cat150 replacement card for perspecta in a panastereo one would need a edgestrip adapter and some external power possibly and logic switching interface
The simplest solution is to find a old Dolby SA4 adapter that was a one unit high box to hold the 150 outboard on a CP100 and use it as a standalone perspecta box

Posted by Mitchell Dvoskin (Member # 751) on 10-29-2008, 11:30 AM:

Do these cards have the capability to be calibrated? If so, is calibration film available? I know that actual Perspecta Intergrators from the 1950's requrired calibration from test tone control film, much as analog Dolby stereo needs calibration. Each of the control tones needs to be calibrated for the correct volume level.

Posted by Steve Guttag (Member # 268) on 10-29-2008, 01:16 PM:

Nope, the cards need not be calibrated...they work right out of the box. They use very stable circuits and don't need tuning. Also, now that most projectors have sync motors...the frequencies are going to be very much on target. That said, I've used it with a Simplex gearbox type soundhead with an async motor without problems.

For the Panastereo...it will need to be home brew or via an SA4 as Gord pointed out. You could also use a CP50 frame and power supply. All you need is the power for the card and to feed the inputs/outputs. The Pana has preamp outs and between the Digital 1, 2 or 3 inputs you should be able to have a suitable input. It is possible that the preamp outs may be a bit hot...I forget the buss level. However, since the CM353s are compatible with the Cat 280T...the levels should be close enough.

Steve

Posted by Stephen Furley (Member # 1277) on 10-29-2008, 01:42 PM:

Gordon,

I acquired an old SA-4 for that very purpose, though I haven't used it yet. I would guess that just about all processors have something basically the same as the Dolby pre-amp outputs and mag/aux inputs even if they're labeled differently that you could patch the thing between.

quote: Steve Guttag
I've only ever used it in a CP200...worked like a charm. The "Surround" feature will work (though the early cards had an incorrect part stuffed)...however, it does not have the necessary delay to avoid a horrible reverberation effect in a large room....and...probably more importantly...Perspecta films didn't have surrounds.

The 200 is a nice processor if you want to start doing strange things.

You are correct about Perspecta films not having a surround channel of course, but it was proposed that they would add one at a later date. It's mentioned in one of the original Perspecta documents in the Widescreen Museum, using a 25Hz tone, if I remember correctly. I've never heard of this anywhere else, and when I asked Bob Eberenz (I hope I've spelled that correctly) he assured me that it was never implemented. I can't remember the exact wording that he used, but it was something to the effect that it was really just a proposal which was put forward, rather than a definite intention which is closer to what the document says.

For anybody who is not familiar with the Cineman cards they have the option, which can be disabled by a jumper, to create a surround channel in a quite different way; they send the mono Perspecta sound to the surround output in addition the the three main channels when all three tones are detected. The fact that the card replaces the Cat. 150 means of course that it cannot use the delay on that card, and to have included a delay on the Perspecta card would have greatly increased the complexity and cost of the card. Plus, as Steve has pointed out, Perspecta didn't have a surround anyway. I would suggest disabling the surround option on these cards, which I did on mine as soon as I received it. It might be interesting one day to try it just to hear what it sounds like.

Posted by Cameron Glendinning (Member # 3516) on 10-29-2008, 03:42 PM:

How many films were made in Perspectasound? I remember that Forbidden Planet and (I think)Fantasia was, anything else?

Posted by Mark Gulbrandsen (Member # 72) on 10-29-2008, 05:22 PM:

All VistaVision pictures from the beginning had Perspecta as well as alot of MGM stuff... All Tom And Jerry Cartoons for instance had it.

Mark

Posted by Dick Prather (Member # 1136) on 10-29-2008, 05:24 PM:

I have one of Dion's cards and it works great. It was being used in a CP-100 and had no problems. One needs to run in stereo with the noise reduction OFF.

I also had a extra SA-4 and was going to try and hook it up through format 3. Have since updated to a CP-200 and have not done anything to it yet.

Can the CP-200 Aux Unit be used to house the Perspecta card and something set up for 06 or should I stay with a SA-4 tied in to the 200? Any suggestions???

As for Perspecta films, it was used in the 1950's. Lots of MGM, Paramount VistaVision, some Allied Artists, and probably others. By the late 50's it was gone but was much more popular in Japan. For a mono track it does indeed sound good.
Dick

Posted by Sam D. Chavez (Member # 1841) on 10-29-2008, 06:07 PM:

It would take some real work to kludge a mod to put this card in the aux rack. IMHO better to leave it as an outboard frame.

This, from someone who once devised a way have two CP200 B-chains so a cinema at MIT (the real one) would be a able to utilize a non perf silver screen with speakers above the the proscenium, or a regular white perf screen to play standard product.

Alas, the place was never built.

Posted by Steve Guttag (Member # 268) on 10-29-2008, 07:32 PM:

Everything is possible with the CP200!

There would indeed be a bit of work involved. It wouldn't be the end of the world to get one of the available sockets to work...infact, Dolby devised a way for inboard surround-EX to do just that....a Cat 150 is mounted in the Aux rack with a logic card. The mod (I've done two) takes less than an hour to do. They used the slots for the never used mid-p and mid-q delay boards.

The trick then is to get the audio back in and switched (and at the right level). The level part is easy to deal with via resistors...the output of a Cat 150 is 500mV...the CP200 runs on 300mV buss levels.

To be real slick...I ask...do you use your mic? If so, do you play it through the stage channels (and get feed back)? If the answer is no to either question... It is possible to bring the Perspecta decoded signal back through the mic inputs on the Cat 141 in SK16.

Remove the jumper for Mic-Center and discard.

Connect the Left signal to A22, the Center signal to B4 and the Right signal to B23. Program Cat 153 Opt for the "Non-Sync Mic" control on your desired format number.

So you want to use the funky surround thing too? No problem because you are going to need to silence the mic that would be feeding the surround since you are going to have to use the Non-Sync Mic control line (aka control line 18) to select LCR.

On the next Cat 141A (Slote SK18) the surrounds can be picked up. Connect the signal to B4 and B8...then also program Optical Stereo surround (I believe the Flow Chart is incorrect in calling for Future 5 here). If you have any Cat 150s kicking around that were made of two boards...separate them and use the delay board in the Acc rack to delay the surrounds...again, some mods are likely needed (I haven't thought it out that far) but I'm telling you, damn near anything is possible, sound wise, with the CP200. By far, the best designed processer for cinema, ever. Its only real major design flaw, in my opinion, was having the subwoofer output come from the Processing unit rather than have the signal flow down with the rest of the outputs. It would have given the Cat 137 a little more to do than just be a line amp card and made the whole JM11/21 thing a bit cleaner when the digitals came along....but Christ it was designed in the late '70s!!! Not bad for processor that came out 28-years ago.

Steve

Posted by Gordon McLeod (Member # 33) on 10-29-2008, 08:44 PM:

I somehow also remember that there was a version made for the USL JS serries processors by the same US maker

Posted by Stephen Furley (Member # 1277) on 10-30-2008, 04:00 AM:

How do you kill he NR on a 65? I've done it by removing the cards and attaching jumper connections to the backplane via croc clips, but that was only for a few minutes use to demonstrate the process. There's got to be a better way, should be possible to install a switch to short or open some diodes, if I knew which ones.

quote: Mitchell Dvoskin
Do these cards have the capability to be calibrated? If so, is calibration film available? I know that actual Perspecta Intergrators from the 1950's requrired calibration from test tone control film, much as analog Dolby stereo needs calibration. Each of the control tones needs to be calibrated for the correct volume level.

Mitchell, I will send you a private message later today.

I think there are two issues here. Firstly, there is the tuning of the filters in the integrator to match the tone frequencies being received frpm the optical pre-amp, Steve has largely dealt with this. Secondly, there is the question of equalisation of the signal to ensure the corect amplitude of sound in each of the three channels. Obviously, if the equalisation of the signal at the bottom end is wrong then this will affect the amplitude of the tones, and therefore of the sound fed to each output channel. All I can say is that when I had my card I didn't have to adjust anything, and it sounded ok. I think there are some presets on the card, but I didn't touch them.

The card is almost all discrete components, and there are a lot of them; it's a very full card.

Dion calibrates the cards themselves using electromically generated tones, of course, this ensures correct levels within the card itself only if the correct levels are being fed into it, and the only way to ensure this is to play calibrated test tones from film on the actual soundheads to be used, and obviously he cannot do this without visiting the actual installation. He has an original Perspecta test/demo film which he plays at his 'Fantasic Fomats' lectures, an I believe he does normally test the cards with this, though obviously not on the actual installation to be used, so the levels of the tones beinf fed to the card must be in question. I received a note from Susan saying that my card had not been tested with film as the test film was in Norway at the time. It sounded fine to me when I used it. I suppose stictly speaking the system should be calibrated to correct for any inbalance of the equalisation of the signal at the bottom end, but I didn't have the means to do this, and it didn't seem to be necessary. It should be possible to get a lab to record a test film with a few seconds of each of 30, 35 an 40 Hz. tone at calibrated equal amplitude if you wanted to, but I had no problems with any audible inbalance between the channels.

I have heard 'Forbidden Planet' through the original integrator at the Loew's Jersey in 2002, and the first few minutes of it through one of the modern cards at Bradford in 2005. I had to leave at that point to catch the last train back to London. Obviously, hearing the two devices in two different auditoria, and almost three years apart is not the ideal way to compare them, but the results sounded pretty similar to me. I don't know if Dion carried out any calibration of the installation at Bradford before this show. Of course, what is really needed is to use a cinema with both types of equipment installed, and to switch between the two to compare them. Unfortunately, I have only ever seen two original integrators, one in England which hadn't been used in decades, was in poor condition and had lots of hum, and the one at the Loew's Jersey, which didn't have a processor which could take the modern card, so such a comparison wasn't possible.

The only material I have played through my own card is a couple of minutes of an unknown feature and a few cartoons. This was the only material which I was able to obtain, and was used simply to demonstate the process.

Something Dion did mention at Bradford was the possibility that the magnetic track for the 35mm version of 'Around the World in 80 Days' which used Perspecta on the surround channel still exists, and might be played at a future Widescreen Weekend. I've heard nothing since, but I was not at the 2006 or 2007 events. I would be very interested to hear this track, which was used on both 35mm 4-track mag prints, and I believe of the sep-mag track which ran with the infamous 34mm print in London. There is a photograph which certainly shows an Integrator in that installation. This needed a modified integrator, but details of the modification exist, and i shouldn't be difficult to do; I think the main difference was that when no tones were present the signal was fed to all three output channels, rather than none of them, as it would be with conventional Perspecta.

[ 10-30-2008, 05:16 AM: Message edited by: Stephen Furley ]

Posted by John Stewart (Member # 989) on 10-30-2008, 04:05 PM:

I didn't see the 2nd page of post and I found my answer there.

John

Posted by Stephen Furley (Member # 1277) on 10-30-2008, 04:22 PM:

When I bought my card they were 300 pounds. This is also the price which was printed on a leaflet which was available at the time. I don't know if the cards are still available, nor what the price is now if they are.

The cards were very professionally made, looked exactly like a mass produced card. Considering the small number involved, I think Dion said that he sold about 30, I'm surprised that he was able to have even the blank cards produced for that cost, never mind buying the several hundred components and hand-soldering them all in place, and testing the finished cards. I think the price was a real bargain.

I would guess that most of the cost for the production of the cards was the setting-up cost, so Dion may well have ordered more of them than he thought he'd need, so he may still have some in stock. From memory, I think all of the components were readily available standard ones, so if he does still have any blank cards in stock it would be possible to build more, if he has the time available to do it, and is willing to do so. The production of these cards certainly cannot have been a money spinning exercise.

Posted by Ron Curran (Member # 3631) on 10-30-2008, 09:35 PM:

Many films that played with Perspecta have later been available with full stereo. The dvd of Gigi for example. Also, the scene from High Society in That's Entertainment was full stereo on the 4 track mag print I played.

Were many of the Perspecta films recorded in stereo?

Posted by Stephen Furley (Member # 1277) on 10-31-2008, 04:22 AM:

I'm pretty ure 'Forbidden Planet' was released in both 4-track and Perspecta. Prints of 'White Christmas' with mag stripes on them also existed, but whether they were from the original release, or were made later, I don't know. I also don't know what was recorded on the stripes since the cinema I saw it in was only equipped for mono optical, it could have been a full 3 or 4 channel stereo mix, or the Perspecta track decoded and recorded on three channels, as is sometimes done with DVDs today, or mono recorded on the centre channel only, or mono recorded on all three of the screen channels. I don't even know if the print carried all 4 stripes, since I didn't actually see it, but the projectionist told me that it was a mag-optical print, and remarked that it was a pity that he could only run it in mono optical.

Something else which Dion told me about his Perspecta cards was that he had supplied one to a company who were going to use it to convert Perspecta tracks to Dolby Digital, for use on DVDs, as mentioned above. This was for Japanese films, but I cannot remember the title of the one which had been released.

There were also rumors that the mono French track on the 'Forbidden Planet' DVD was actually in Perspecta, with the tones intact. I borrowed a copy of the DVD from somebody, and tried putting it through the Perspecta card; there were certainly no Perspecta tones on the copy that I tried. There has been more than one DVD release of this film, so it's possible that another version may have had it, but I'm skeptical.

Posted by Phillip Grace (Member # 2262) on 10-31-2008, 06:04 AM:

I bought one of the cards from Dion Hanson in December last year. Price was something like GBP 300.00 from memory. At that time he indicated that there were still a few available. Unfortunately I have not been able to use it yet - large vet bills for cat repairs intervened. I got hold of an SA-4 to mount it and will configure it into my CP-200 system, and also had in mind to set up a CP50 with the necessary parts for a portable Perspecta processor to use in other situations.
There is a print of Fritz Lang's "Moonfleet" in circulation which has its Perspecta soundtrack. There is clear print-through information from the track neg on the print.
I'd be keen to know how to get Lt and Rt out of a CP650, if anyone has done that.
Cheers.

Posted by Steve Guttag (Member # 268) on 10-31-2008, 06:42 AM:

Off the top of my head...use the test points in the front normally used for alignment...they are ideal as they have zero processing on them.

I don't recall the CP650 providing a "preamp output"

Steve

Posted by Phillip Grace (Member # 2262) on 11-01-2008, 10:32 PM:

Ah! Thanks, Steve.

Are the optical inputs are always live? I guess it would be possible then to come back into the 650 through the External analogue inputs and select Format 11 for playback?

My expereince of the CP650 is that it is a pretty bullet-proof processor, and will remain relevant for quite a while. Perhaps the limited number of format selections on the front panael could be improved with a menu selected assignment for all of the eight format buttons, in the same way that the U1 and U2 buttons are assignable now. That would make at least that part of the control system equivalent to the thumbwheel switches on the CP200. (ie any four formats available at any time).
A fully optioned CP650 seems to be a pretty capable processor. Maybe a little more signal processing software could be added to cover some of the "legacy" formats.

Posted by Stephen Furley (Member # 1277) on 11-29-2008, 03:56 PM:

I've had an enquiry from somebody who wants to know if the Perspecta card, housed in a SA-4, could be connected to a CP-650. I don't know much about this processor, I've never used one, and I saw one for the first time just a couple of weeks ago. Can somebody tell me if it has suitabe outputs and inputs to be able to do this?

Edit:

I've just seen the posts from Steve and Phillip about getting the signals out of the 650 and back in again. What's format 11; is this available on all 650s?

Posted by Pete Naples (Member # 761) on 11-30-2008, 10:02 AM:

Yes, Format 11 is available on all 650s.

Posted by David Graham Rose (Member # 1450) on 11-30-2008, 01:58 PM:

Greetings from a wet Cambridge

Quote: "

My expereince of the CP650 is that it is a pretty bullet-proof processor, and will remain relevant for quite a while. Perhaps the limited number of format selections on the front panael could be improved with a menu selected assignment for all of the eight format buttons, in the same way that the U1 and U2 buttons are assignable now. That would make at least that part of the control system equivalent to the thumbwheel switches on the CP200. (ie any four formats available at any time).
A fully optioned CP650 seems to be a pretty capable processor. Maybe a little more signal processing software could be added to cover some of the "legacy" formats."

Version 2.3.6.3 of the Processor software allows the user to assign all 8 format buttons.

Goodnight

David.

Posted by Steve Guttag (Member # 268) on 11-30-2008, 02:56 PM:

Yep, you are correct...as of 2.3.6, even formats 5 and 10 are now assignable...so long as a Cat 773 is NOT installed. However, that only seems to apply to those running SR and DC models...not Ds and full CP650s

Steve

Posted by Frank Angel (Member # 248) on 09-18-2009, 04:15 PM:

We are going to play FORBIDDEN PLANET again and I am wondering if all of the prints carried the Perspecta signals or are some missing it? I would consider trying to find a Perspecta unit if I could be assured of getting a print with it was not going to be a hunting expedition.

If the answer is, getting a Perspecta print is not a problem, then what would be the best place to look for a integrator unit? Anyone have one sitting on a shelf they would like to rent?

For those of you who have heard the process on FP, how impressive is the steering....is it worth the effort? I have a sound engineer who has an incredible ear (mixes audio for Jazz at Lincoln Center). All I would have do to is let him watch the DVD a couple times, which has the steering on it, yes?, and I am confident that he would be able to mimic whatever they can do with the three tones, he can easily do manually sitting at his console in the middle of the house. Might be allot easier than finding an integrator and getting it calibrated and all.

Posted by Stephen Furley (Member # 1277) on 09-18-2009, 05:12 PM:

Frank, I can't say if all prints of this title have Perspecta on them, but there are certainly prints available which do; It's been run this way at both the Loew's jersey and the Pictureville within the last few years.

Are you looking for an original Integrator unit or a card to fit a CAT. 150 slot? If a card, then John Stewart has my one at the moment, see higher up this thread, and I'd be happy for you to borrow it if you can come to some arrangement with him re. postage etc.

Posted by Frank Angel (Member # 248) on 09-18-2009, 06:38 PM:

That's great, Steve, I will contact by email as soon as I can pin down the print issue. No point going through a lot of work if I can't get my hands on a Perspecta print.

Thanks big time.

Posted by Dick Prather (Member # 1136) on 09-18-2009, 10:10 PM:

I have a very pink print of Forbidden Planet from the 50's. Unfortunately it has a couple of reels with VS but still runs.

The soundtrack had electronic music and sounds great in Perspecta Sound. Separation close to magnetic. Worth running it that way if you can. Unless they played or remixed the Perspecta tones should still be there.
Dick

Posted by John Stewart (Member # 989) on 09-18-2009, 11:13 PM:

The print of FORBIDDEN PLANET we had this summer did have the tones in it. You can't miss it when you look at the print, the sound track is never "quiet". Always some low freq. present. I can get a print number for you sunday if that would help. The print is about 10 years old but is in good shape.

Email me direct if you need me to send the card soon. I don't always get to look at the forum. Oddly enough, AMERICAN IN PARIS the next to last reel had Perspecta encoding in the 1st half of the reel. The rest of that reel plus the last reel of the print is SVA.

J

Posted by Jack Theakston (Member # 4484) on 09-19-2009, 12:31 AM:

The Perspecta mix on FP is very good. Quite aggressive, compared to the VistaVision titles which didn't utilize the process much at all. Unless they re-recorded the track (doubtful), they'll still be there.

FYI, all of the cards I've seen and heard DON'T have the GAIN control that original Perspecta integrators have. That's half the system!

Posted by Gordon McLeod (Member # 33) on 09-19-2009, 09:18 AM:

Dions card from the UK has gain riding
the one made by chace did not

Posted by Richard P. May (Member # 3598) on 09-19-2009, 10:27 AM:

The optical track negative which we used thru the MGM/Turner/WB period had the Perspecta tones, so assuming you are booking FORBIDDEN PLANET with WB Classics, it will be Perspecta.
It can be easily identified, assuming the original leaders are intact, as "Perspecta" is written on the sound track in the identification frames.
While the sound is sort of corny the way it was used, so is the movie. Both are quite entertaining.

DM

Posted by Dick Prather (Member # 1136) on 09-19-2009, 05:03 PM:

The Perspecta prints, I ran, always had a tone on. The Perspecta units took 7 to 14 seconds to turn on and dropped in 3 to 4 seconds. This kept the unit on through out the print and changeovers. Later prints had lower tone levels.

I used a Fairchild Perspecta unit to start. I had to go through it and replace most of the caps. The hardest was getting the tone filters back on frequency. Never got the 40 Htz perfect but close.

I paid 300BP for the Dion's card and it works great. Plugs in to the Cat 150 slot. Leave the processor in stereo with NR off and your all set.

I plan to use a separate SA4 cabinet for the Perspecta card into a CP-200 when I can figure it out.

If you are using a subwoofer or base boost these must be turned off as they will pick up some of the tones. It's nice to hear a print the way it was intended.

Dick

Posted by Stephen Furley (Member # 1277) on 09-19-2009, 06:09 PM:

'Forbidden Planet' is probably the best Perspecta that I've heard, though I have to admit that I've not heard a great deal. What I'd really like to hear is the 4-track mag for the 35mm version of 'Around the World in 80 Days', which used a slightly modified Perspecta on the surround track. It's strange that this doesn't seem to have been used on the six track mix for the Todd-AO version.

The cinema which ran the infamous 34mm print of this in London, the Astoria Charing Cross Road, which had been a music venue/nightclub for many years has been demolished within the last few weeks.

Posted by Claude S. Ayakawa (Member # 1401) on 09-19-2009, 09:08 PM:

Toho Studios in Japan also released ther films with Perspecta Sound. Although all of the titles are in Japanese. The end title card with "Owari" (The End) in large kanji in the centre. It states very clearly on the bottom left of the scope frame in English -Perspecta Sound. Some of the later films by Alira Kurosawa that was released by Toho such as AKAHIGE (Red Beard) had it as well as every TohoScope films from that studio

-Claude

Posted by Stephen Furley (Member # 1277) on 09-20-2009, 01:33 AM:

Use of Perspecta continued in Japan for some time after the the process was abandoned in the US and Europe.

Posted by Tom Doyle (Member # 1474) on 09-23-2009, 03:00 PM:

Frank, when are you planning on doing the show? I have a Perspecta unit that you're welcome to borrow. It's unrestored but I could start working on it ASAP.

Posted by Frank Angel (Member # 248) on 10-08-2009, 11:23 PM:

Hey guys, first off, many thanks for the generous offers. But I just found out they are scrapping the FORBIDDEN PLANET engagement, at least this time around. It was to be part of our bi-annual, three day International Electro-Acoustic Music Festival. FP is the first film use the theremin or "aetherphone" instrument exclusively as the music score (Bebe Barron and her husband or brother, not sure which & can't remember his name either -- whilst Bebe Barron just flows off the tongue).

Our Conservatory of Music was to have both a Theremin and Moog artist demonstrate and give a concert playing these early electronic music synthasizers. The Conservatory has always been very prominent in the electronic and Musique Concrète genres -- I actually helped set up one of the very first Moog synthesizers in a studio down the hall from mine. Unfortunately, the theremin player had to back out of this concert/film event, so the producers don't want to throw the movie away without the full concert and special event aspect of it and all the attending hype they expect they can generate.

It's a bi-annual festival, so it will come around again in the spring. By then I should have the technical end of it nailed down.

Again, guys, thanks for the offers; I may come a-knocking again in March.

Oh, PS -- I may have an original Perspecta unit that I can get my hands on, but Tom, you mention the originals need to be refurbished? Is that just replacing caps or it is more complicated a job?

Posted by Mark Gulbrandsen (Member # 72) on 10-09-2009, 07:25 AM:

Frank,

All caps should be replaced for safety reasons. The bandpass filters need to be checked to make sure they are within tolerance. As capacitors age the bandpass filters can drift off their intended center frequency. Then the control tones have no effect what so ever. This is not that all that difficult with the aid of a low frequency spectrum analyzer such as the old Hewlett Packard 3580A which has a 1 hz resolution.

Mark

Posted by Frank Angel (Member # 248) on 10-09-2009, 12:43 PM:

Thanks Mark; replacing the caps no big deal, and I can scrounge around the other recording studios and the TV center here for a spectrum analyzer, but if they are still off, is there an easy way to tune them -- adjust pots perhaps? -- or will it be replacing resistor and cap values to try to hit the mark?

Posted by Dick Prather (Member # 1136) on 10-09-2009, 01:48 PM:

Frank, the one I rebuilt was a Fairchild unit. Probably the most common. There are four or five other brands in the States. All are simular in circuit design.

The filters were accessable after pulling the tops off and melting the wax out from inside the filter cans to get at the coil & caps.

I remember finding the caps in the filters being the same value and each coil was wound to the correct frequency. The caps were replaced and all but the 40htz filter were right on. Some cap padding was used to get the 40htz filter close.

I did some more circuit mods to bring the trigger tone levels up in the processor and it worked great.

Good luck, Dick

Posted by Mark Gulbrandsen (Member # 72) on 10-09-2009, 04:15 PM:

Frank,

The only thing you need to do when rebuilding the coils is to use the spectrum analyzer to make sure they are still within tolerance. Sometimes you can select a capacitor from a group of caps of the same value to get them in just right. Caps can also be paralleled to get things to where they need be if necessary. You may also not be aware that C. Robert Fine... the engineer of the many of the famous Mercury Stereo Recordings of the 1950s was the man behind Perspecta Sound. These recordings were primarily done on a three channel Westrex 35mm mag recorder and many of these recordings have stood the test of time and are still considered to still be some of the finest audio recordings ever done. C. Robert Fine Info