35mm optical sound /digital processor marriage?

[Luke Anderson]

I’m not totally sure on all my vernacular’s and parts in the digital world so hang with me.

We are hooking up to run 35mm again after a decade + of all digital. We need a card to plug into our digital AP 20 processor that will read the optical sound coming out of our BA.CP analog sound track reader.

How do we find this? Any leads?

Thanks in advance,

Luke

[Stefan Scholz]

I have recently installed AP units which came with the film projector card, as that site wanted to keep the film capabilities in their auditoriums.
So from theory they do have these boards, and there's a good chance to buy a spare part card. I assume, it's not really a cheap item.
Check with your service provider that installed the AP unit.
The other option, a legacy sound processor and outputs feeding into the 8 ch analog in of the AP. Not as comfortable, you may use the GPOs
provided in the AP to control the formats in the legacy processor. Keep in mind old Doly CP are pretty noisy on the analog outputs, compared to
today, acoustical on indication is there..

[Marco Giustini]

As Stefan mentioned, if you cannot find the film card for the AP20, I'd recommend a CP650 into the 8ch input of the AP20. The AP20 is super flexible when it comes to automation, I'm confident a competent installer could set up network commands so you could automatically control the 650 from the AP20 - but really you can leave it on 7.0 and on the sound format it's supposed to decode, unless you need to switch between Mono/A/SR as well.

CP650s have been reliable - but the power supplies which are nothing that cannot be replaced with a third party one. The 650s should also be relatively quiet in terms of noise floor and I don't think are too expensive to find. The 650 has balanced outputs and the AP20 should have balanced inputs so you should get a good result.
I wouldn't recommend any older ones (CP500 or CPXX).

[Steve Guttag]

Oh, I'd counter that...I'd wager one could keep a CP65 going longer than a CP650. I'd agree that a CP500 would be far riskier than a CP650. So long as one has a source of spares on the CP650, one is in good shape. The CP650 is certainly the smallest/cleanest "film adapter" to a DCinema system that also can include Dolby Digital.

[Sean McKinnon]

any Datasat dealer should be able to get the card for you.

[Luke Anderson]

I have a message out to Datastat. Also we don’t really plan on running any newer ish prints with digital sound on the print … just keeping it simple with an optical reader.

[Marin Zorica]

I did install quite few AP20/25 with film card, and they do perform well, but with reverse scan sound head. In case normal sound head with solar cell you either need preamp because of low level. But, also i did use CP650 so you have both srd and dolby digital, a s just feed it to ap 8ch input.

[Luke Anderson]

Update:

we ordered and installed the datastat card. We had to find and replace the LED as we had issues with gain. Now we are getting the “motorboating” sound. We have the best balance in all channels, with a motorboating noise. I remember this problem coming up in the past, but it’s been so long and we had techs that came in to fix the problem.

any advice would be great,

Luke

[Gordon McLeod]

Update:

we ordered and installed the datastat card. We had to find and replace the LED as we had issues with gain. Now we are getting the “motorboating” sound. We have the best balance in all channels, with a motorboating noise. I remember this problem coming up in the past, but it’s been so long and we had techs that came in to fix the problem.

any advice would be great,

Luke

Probably alignment need a buzz track and a L/R alignment loop and a scope