Film-Tech Forum ARCHIVE: Distorted sound in digital I/O AES3, CP650

This is topic Distorted sound in digital I/O AES3, CP650 in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Mark Barabas (Member # 6221) on 04-12-2011, 04:56 AM:

Hello all,

have you ever had experince with distordet sound, which also had some of drop outs in system listed below ?

Doremi DCP 2K4 - 4xAES multicable - Dolby CP650 Optional I/O (cat 790 installed).

I also build converter from AES to SPDIF, but this didn´t solve the problem.
Is it possible that hign AES voltage output could broke input parts of Cat 790 ?
There is also some cracking and sizzeling noise in particularry surround channels.

[Confused]

Posted by Carsten Kurz (Member # 5396) on 04-12-2011, 05:34 AM:

I don't remember wether it was a 650, but I do remember that one Dolby processor once created strange sounds due to a broken firmware for EQ. If everything else fails, you might consider upgrading or reflashing the firmware.

- Carsten

Posted by Pete Naples (Member # 761) on 04-12-2011, 05:07 PM:

Output of Doremi - 110 Ohm Balanced.

Input of CP650 -75 Ohm UnBalanced.

You need to be very careful to do this succesfully.

Really there should be transformers between the Doremi and the CP650.

For example web page

Posted by Steve Guttag (Member # 268) on 04-12-2011, 07:35 PM:

Or get the Odyssey Products Option AES board...it has the transformers on it and has the traditional DB25 balanced AES input (it also replicates the CP650 I/O connector for any of your existing (surround) wiring.

-Steve

Posted by Tony Bandiera Jr (Member # 2365) on 04-12-2011, 07:53 PM:

I second Steve on the Odyssey board, it works great!!

Posted by Mark Barabas (Member # 6221) on 04-13-2011, 03:53 AM:

Many thanks for all of you guys.

I will try update firmware, but I think it won´t help because all other sources works fine.

I will also try transformer converter, because Iused only voltage divider with resistors.

I will let you know where probles was.