Film-Tech Forum ARCHIVE: RCA Soundhead confusion.

This is topic RCA Soundhead confusion. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bhaskar Dhungana (Member # 1283) on 07-07-2006, 04:31 AM:

We have a pair of old projectors that have the RCA MI 9051-31 (I am told the 9031 being the 70mm option) soundhead that needs to be converted to read cyan tracks. When I asked Component Engineering, they told me that they have kits for RCA 1040 and 1050 projectors. Would any of these work? Does anyone know anything about these soundheads?

Posted by Mark Gulbrandsen (Member # 72) on 07-07-2006, 07:38 AM:

Don't waste your time with Component Engineering... Go with the BACP or the Kelmar in that order. The BACP is by far the best of the bunch and the easiest to install. The Kelmar is #2 in my book. Some power supply issues but other than that they are very well made and very reliable. Component Engineering just isn't what it once was.... Stay away from the JAX Light... or Jokes Light as I call them. I am in the process of replacing as many of them in my servicing areas as I can.

Mark

Posted by Steve Guttag (Member # 268) on 07-07-2006, 09:16 AM:

Mark is wrong about Component Engineering. They are excellent. This does not take away from Kelmar or BACP but Component Engineering is not the 2nd or 3rd class system Mark just made them out to be. They also use real power supplies unlike some of the others.

Posted by Richard Fowler (Member # 893) on 07-07-2006, 09:40 AM:

For the price, Component Engineering is very effective; the new style power supply has features and advantages over the other competitors. All three are fine.

Posted by Barry Floyd (Member # 385) on 07-07-2006, 11:08 AM:

I'm running an RCA-9030 with a Component Engineering reverse scan reader in one of my booths and have never had a problem with it.

I've been running a Component Engineering reverse scan reader in my original booth for over 3 years, and like the other.. never had a problem.

For my application in a drive-in, Component Engineering was the most logical choice money-wise and without all of the other bells and whistles I didn't need.

Posted by Gordon McLeod (Member # 33) on 07-07-2006, 02:49 PM:

I too have had few issues with the CE readers

Posted by Pete Naples (Member # 761) on 07-07-2006, 03:11 PM:

Thirded, or is it fourth'ed!

I 've had far more problems with Kelmar reverse scan the CE. And we've got a massively bigger install base of CE, so the stats aint good. Nothing ot choose between them in performance otherwise.

Posted by Louis Bornwasser (Member # 3063) on 07-07-2006, 03:24 PM:

My early experience with Com. Eng is not good....led's that were glued in, etc. OTOH: I have sold about 400 Kelmar and had only 2 power supplies fail. (Did have to add pins to make the early led brackets solid.) LOuis

Posted by Mark Gulbrandsen (Member # 72) on 07-08-2006, 12:09 AM:

quote: Louis Bornwasser
I have sold about 400 Kelmar and had only 2 power supplies fail.

It seems that all of the older Beige units fail eventually so I'd be expecting a somewhat bumpy ride down the road a bit Louis.

As for C.E. it would still be my last choice. I dislke the LED mount, especially on the basement digital readers. One has to remove and disturb one led's alignment to get to the other one. Power supply problems aside Kelmar thought theirs out alot more thouroughly from day one with important brackets being dowel pinned and exactly relocatable in seconds without disturbing their alignment position, convenience and accuracy!. Even though the C.E. led mounts are copper which is the best metalic conductor of heat the amount of heat dissipation is so low as not to matter... the copper moves the heat away from the LED faster... faster that is till all the copper reaches thermal equilebrium and the temperature begins to climb on the entire assy. On the other hand the black anodized Kelmar LED bracket has alot more surface area and is finned for a better chance at more efficient heat dissipation, hence it is alot les likely to climb in temperature as fast.

Both C.E. and Kelmar have similar optics so that is not an issue.

The BACP power supply is fine and very stable, in fact switchers are able to make needed corrections to current/voltage requirements ALOT faster than conventional pass type or current regulated supplies can, this makes any power surges, ets alot less likely to cause any problem in the reproduced sound. This is also one of the reasons that Kelmar uses switchers. Both types switch at a frequency that is so high that any interference it might generate generated is irrelevant and any harmonics are even much higher. The BACP has a USER replacable LED head, and USER replacable pcb assy. It has almost as large an LED bracket the Kelmar's. BACP has the fastest optics and runs the LED at the lowest current. They have consistantly also given us the LEAST trouble(ZERO!) with well over 200 installed.

Mark

Posted by Demetris Thoupis (Member # 833) on 07-08-2006, 03:37 AM:

Well Mark,
We realised that you LOVE BACP readers!!! [Smile]

So do I. Converted over a dozen here in Cyprus with no problems and the best sounding results. They sound so damn good that you can not distinguish when it is Digital and when it is Analog playback. But I do not believe CE or Kelmar are not good. They are just not THAT good as the BACP readers.
Way to go Sam.
D

Posted by Bhaskar Dhungana (Member # 1283) on 07-08-2006, 03:37 AM:

What I meant to ask was "Is the model of RCA soundhead that CE makes (1040 and 1050) its reverse scan compatible with the sounhead that I have (MI-9051/31)?

Posted by Mark Gulbrandsen (Member # 72) on 07-08-2006, 06:59 AM:

Demetris,

No, I also like the Kelmars in spite of the power supply issues. They are my 2nd choice for scanners and my first choice for basement digital. Just about everything Kelmar makes is much better thought out than most other companies products are. Reliability is their key design basis and even though alot of the supplies are failing many are close to 10 years old.

As for supplies C.E. wins in the conventional AC to DC department and BACP on the switcher end of things.

Bhaskar,
Yes, it should fit. The other manufacturers scanners are backwards compatible to the 1050 but you may have to modify the drum just slightly to get the LED close enough to the film... some of those older drums are thicker near the scanning edge. The 9050 is almost the same as the 9030. The 9050 was designed to keep flutter specs low and also drive heavy loads like a Brenkert BX-100. The drive for the projector comes from the lower bronze gear instead of the upper. That extra fibre idler gear making up the 1050 is no longer available even from Wolk necessitating converting them to 9030's when the gear fails. No 9030's were ever used here as a 70mm projector sound head that I am aware of although there could have been some experimental stuff. Crown of Japan made a three piece 35/70mm projector that had a 9030 look alike, they had second model that looked like a DP-70.

Mark

Posted by Richard Fowler (Member # 893) on 07-08-2006, 02:18 PM:

As Mark noted the C.E. kit will work on 1040 / 1050 / 9030 / 9050 soundheads. The end of the sound drum may need to be slightly shorten and the interior rechamfered but this is a very rare problem. It depends if your soundhead was made in the USA / Japan / India. Some Westrex soundhead drums need the same work since some have a thick edge.