CP500 to amplifier

[Neal Scanlan]

Hello,


I wondered if anyone could help me.
I am putting together the sound system for my 35mm projector, I am using a Dolby CP500. The processor appears to be workings correctly and I can hear sound on all channels through the monitor. The problem I have is that when I connect an output to an amplifier there is no sound. Does the CP500 require a pre-amp or an auxiliary piece of equipment as an interface to the amplifiers?

[Jerry G. Axelsson]

Neal, How are you?

I suggest that you go to the forum "Warehouse" above and look up the installation manual för the CP500. All your questions concerning this should be answered in this document.

[Neal Scanlan]

Hello Jerry,
Thank you for getting back to me, I am well and I hope you are also.

I have used the information available in the Warehouse, and have studied the manuals but cannot find anything which directly effects the outputs. It is possible to change outputs in the B-chain and I have set these at 50% of their range. At this setting I cannot understand why the amplifiers are not responding. As a test I connected a CD player to the amp directly and it worked perfectly but when I route the CD player through the CP500 and connect the output to the amp I have no sound, yet I can still hear the music in the separate monitor speaker.
I have seen that the Dolby CP650 setup/wiring diagram shows outputs connecting directly to the amplifiers but this is not a detail that is illustrated in any of the CP500 documentation. I'm a bit stuck as to how to move ahead other than connect one output to a preamp and see if this boosts the line level to trigger the amplifier.

I am new to this forum but have been aware of the site for several years. I would like to say to all those people who created, maintain and contribute to it that it is the most incredible and precious place of knowledge, without it I certainly would not have been able to enjoy and grow my interest in these fields to the level that I have so from me to all, thank you.

Neal

[Carsten Kurz]

What monitor speaker - where is it connected to the CP500? The output wiring is given on Page C-2 of the installation manual. You can connect the amps directly to these outputs, nothing needs to go in between. Can you see levels on the CP500 display?

You can see more wiring details here: http://www.film-tech.com/warehouse/m...500REFDIAG.pdf

[Neal Scanlan]

Well thank you Jerry and Carsten, I took the monitor which was a UCG cinema monitor (used by the projectionist to hear the outputs to the auditorium speakers) out of the chain, wired to a speaker from new and it worked. There was definitely some confusion with respects to polarity but I now have a working example to follow for all the other channels