Dolby cp750 aiuto

[Alessandro Orlandini]

Hi everyone, I'm using the translator because I don't speak English, so it won't be accurate. I have a Dolby CO750 that I'm using at home, sending audio via optical cable, but it's compressed. I'd like to know how I can send the audio via DB25 using an HDMI to DB25 converter, or use the DB25 analog input with a 6-channel HDMI to RCA adapter. What do you suggest I do? In the meantime, I'm looking for a used Dolby DSS220 server.

[Marcel Birgelen]

It would help to know what the playback source is...

Meanwhile, if it's not the output from a proper DCI server, then I'd use the multi-channel Analog in on the CP750, using a proper DB25 converter.

[Alessandro Orlandini]

I'm using digital 4 optical cable, but I would like to have multi-channel PCM

[Marcel Birgelen]

Yeah, we already knew that.

But, good luck going from HDMI to 4 x AES/EBU with the right clock signaling et all... not saying it's never going to happen, but is there any reason why the source device can't output multi-channel analog audio? There's nothing magical about the CP750 DAC.

Furthermore, once you get a proper cinema server, you're going to need the 4 x AES/EBU in for that machine. The CP750 multi-channel analog in was really built for alternative content in, like DVD and BluRay players.

[Alessandro Orlandini]

okay, if I buy a 6 channel analog hdmi to rca converter and connect to the analog db25 input?

[Pete Naples]

That's all a long way round for a short cut TBH.
You can get HDMI -> 4xAES/EBU boxes which work perfectly well, but they are quite expensive.
You can get really cheap HDMI -> 8 analogue channels. You get cheap ones which are very meh and more expensive ones which are fine.
But again, a long way round for a shortcut. Especially when the CP750 as a processor isn't all that TBH. It's quite a basic device and quite old now.

For domestic use, stick with a decent receiver. I played around with a CP55 modified to 5.1, then a CP650, then a CP750 at home. Ended up with a Cambridge Audio box because in the domestic environment, it just works.

[Alessandro Orlandini]

I've changed many multi-channel amplifiers, the last one was an Onkyo nr-tx545 and honestly the Dolby has amazing dynamics

[Marcel Birgelen]

If you want something that works also in a professional cinema environment and supports HDMI directly, I'd really look out for a Datasat AP20 or AP25. The CP750 comes with borrowed time, as I expect sooner or later all of them will be hit by the volume degradation issue.

You can get HDMI -> 4xAES/EBU boxes which work perfectly well, but they are quite expensive.

I know of exactly one Chinese box of some boutique seller that builds one of these, it's this one. What others are there?

[Alessandro Orlandini]

Would the Dolby CP850 be suitable in this case? I see HDMI connectors. For now, I've bought an 8-channel PCM HDMI to RCA converter, which is inexpensive. I know there are HDMI to DB25 AES EBU converters, but they cost €400. I might as well upgrade to the CP850 in the future if there are no HDMI issues.

[Pete Naples]

If you want something that works also in a professional cinema environment and supports HDMI directly, I'd really look out for a Datasat AP20 or AP25. The CP750 comes with borrowed time, as I expect sooner or later all of them will be hit by the volume degradation issue.



I know of exactly one Chinese box of some boutique seller that builds one of these, it's this one. What others are there?

https://www.oppostore.nl/en/vanitypro.html

https://www.arvus.com/hdmi-2a.html

I've used both, both work perfectly well. But by the time you have bought one, you might as well have bought a Datasat AP25 or a Trinnov OV2 with a decent de-embedder (actually TBH a £10 Amazon special de-embedder will work just fine)

Dolby CP950 has HDMI natively.

Remember, no Dolby cinema processor will look at a DTS bitstream natively. Trinnov, Datasat and any domestic receiver will though.

Our Cambridge Audio box here at home is so old it doesn't have HDMI, gets fed TOSLINK straight out the back of the TV and just gets on with life. Switch all the room emulation nonsense off though. I do not wish my living room to sound like Wembley, because I am not, nor have I ever watched TV or a movie at Wembley stadium. I'd imagine it wouldn't be a great experience. And pretending to be it in my living room is a really awful experience.

[Alessandro Orlandini]

thanks, for now I got hdmi to rca 7.1 pcm ayino, but do I have to disable the through pass on nvidia shield and tv?

[Marcel Birgelen]

I'd say: Disable pass through. Unless you invest in a "high end" DAC/AVR that can handle most Dolby and DTS formats natively, it's probably best to just send a multi-PCM stream to your HDMI to Analog converter and keep the setup simple. In this case, either your Shield or your TV will handle conversion from Dolby or DTS formats to multi-PCM.

Dolby CP950 has HDMI natively.

I'm just guessing, but I think a CP950 will be a bit out-of-budget here.