Film-Tech Forum ARCHIVE: getting audio from hopper to cp650

This is topic getting audio from hopper to cp650 in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=003812

Posted by David Gibbons (Member # 10887) on 10-07-2019, 09:58 AM:

was wondering if anyone had any ideas for getting audio from a toslink to a cp650

Posted by Carsten Kurz (Member # 5396) on 10-07-2019, 10:12 AM:

If that CP650 is equipped with AES ins, there are cheap converters available from Toslink to S/P-DIF or AES. S/P-DIF will mostly work using a passive RCA->BNC converter, sometimes it is necessary to utilize a simple impedance converter. I would first try one of those simple TOSLINK->S/P-DIF converters with an adaptor cable/plug, see if it works.

Search on ebay or Amazon for 'TOSLINK KOAX'. Some devices come with one direction only, some with both simultaneously.

- Carsten

Posted by David Gibbons (Member # 10887) on 10-07-2019, 10:23 AM:

Thanks I'll look into that.

Posted by Dave Macaulay (Member # 813) on 10-07-2019, 11:54 AM:

First confirm your 650 has a digital input. This requires an option card, not all 650s have them. If it has 7.1 capability (obvious because the surround outputs are on the "OPTION CARD I/O", if it hasn't got the option card for 7.1 that connector should be unused: this option card (CAT680?) has digital inputs... and there are also other option cards for digital input.
The digital input(s) are on that I/O connector also, it's not a simple plug and play job of "connect a s/pdif cable to a convenient RCA jack".

Posted by Scott Norwood (Member # 30) on 10-07-2019, 12:32 PM:

The simplest option might be to convert it to analog and use the external 6-channel input.

About five seconds of searching on Amazon finds this thing:

https://www.amazon.com/Digital-Decoder-Converter-Optical-5-1-Channel/dp/B07116VKTR

It's cheap Chinese garbage, but it's under $30 and will supposedly convert the toslink signal to analog. All you need to do is to make a cable to go from 3x 1/8" connectors to the DB25 input.

Even cheaper converters exist for 2-channel audio.

Posted by Steve Moore (Member # 4753) on 10-07-2019, 07:13 PM:

I can confirm that the cheap amazon box that Scott mentioned above, do work. We have had a few of those powered up daily for the last three or so years to convert optical from satellite receivers into CP55 processors that still exist around some sites in our circuit and they have not let us down yet

Posted by Juan Jose Vazquez (Member # 10496) on 10-07-2019, 07:59 PM:

If the CP650 does not have digital inputs, you can use the 11 format and an external converter such as a GEFEN Scaler.

Posted by Marco Giustini (Member # 4544) on 10-08-2019, 04:39 AM:

Unfortunately I do not share the same luck others have mentioned over those chinese converters. That said, the CP650's digital input is far from being reliable - but maybe with just a single pair it's ok.

Personally, I wouldn't add one of those converters to a professional system. Juan's recommendation is sound though. Gefen products are very good.

Posted by Steve Guttag (Member # 268) on 10-08-2019, 06:54 AM:

I have found Gefen products to be garbage. Every single one has let me down and will not use them or recommend them. As for 6-channel D-As...there are probably DAX602s floating about now. I believe Dolby still has their Aud2DA thing from Doremi and our good friends at Odyssey Products have some D-A converters.