DTS-CD Quad to HDMI converter?

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barfle

1K Club - QQ Shooting Star
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I'm sure I'm not the only one here who is having difficulty integrating his quad decoders into a modern surround system. Most home theater receivers/pre-pros have, at most, one set of surround analog inputs, and I suppose it's possible to rig an outboard switch that would allow three (SQ, QS, and CD-4) decoders to be selected, but getting that to work with a universal remote control is an issue. I read one post on QQ that said there were quad to HDMI encoders, although the post didn't mention any specific item. I've been looking for something like that for a few years, but so far I've turned up zilch.

Anyone have any ideas? How are you handling the multiple format vinyl conversions?
 
Getting audio in/out of the computer is done with what's called an audio interface.
USB, firewire, or thunderbolt to connect to the computer. Audio jacks (in and out) to connect to the audio system.

There are some cheapo unbalanced analog to/from HDMI interfaces available.
They seem aimed at the consumer marker (that doesn't realize there are better products available) and the HDMI connection can be prone to copy protection gone wrong.

There are a number of little interfaces that feature 4 to 8 inputs and/or outputs in the $50 - $300 range.
If you want class A AD and DA converters (boutique audiophile level), Prism, Apogee, and RME are examples of interfaces with such converters. Add a zero to the above prices.

The slick computer to surround receiver is the thunderbolt to HDMI cable from the computer thunderbolt port to the receiver HDMI port.
Slick if you have a 2010 or newer computer and an HDMI input having receiver.
Watch out for scammy products! The Windows computer with a video only HDMI port. The receiver with a video only HDMI input.
The products like an unbalanced analog to HDMI converter. A low grade AD conversion as a workaround for not having the correct analog input on a receiver or not having a digital output on the computer. You'd be really stepping on the audio with such a workaround and paying to do so.

The thing to understand is the analog to digital conversion and the digital to analog conversion. The converters are the big ticket item. Digital is all or nothing this way. Start with a pristine conversion to digital and you can losslessly push those ones and zeros around and between devices. Start with a conversion on the cheap and the ones and zeros you're pushing around are compromised from the start. Go back and forth with D -> A and A -> D too many times and you get loss.
 
How are you handling the multiple format vinyl conversions?

I bought one of these and use it to record the output of legacy quad gear (SQ/QS/CD-4/Q8) into Adobe Audition at 96/24. Once you have the files on the computer you can do whatever you want with them, like add NR, fix channel swaps, and output to various formats (DVD-A, DTS-CD, Multichannel .WAV or .FLAC. etc)

I have the opposite setup as you, I use a vintage marantz quad amp with both vintage decoders and modern disc players hooked up. I use two JVC analog RCA switchers to manage all my devices. You do have to get up and manually press the button but it works quite well.
 
I thought balanced was only required for long cable runs.
 
Focusrite and Presonus make decent entry level audio interfaces for a low price. The B-word products can get a little ratty cheap but aren't the worst
I thought balanced was only required for long cable runs.
"Required" for very long runs yes. Still preferred over unbalanced for short or medium runs whenever possible/practical.

The more important point when choosing gear is that the devices with the combo balanced/unbalanced jacks tend to be higher quality than the ones that ONLY have unbalanced connections. In the similar way that the bluray format suggests you'll get a lossless HD master vs the CD format which is usually the volume war hyped version. There are exceptions.

And there's nothing wrong with a proper unbalanced connection with a proper (not too long) cable (not draped over a power cable) when you have vintage gear to connect.
 
Focusrite and Presonus make decent entry level audio interfaces for a low price. The B-word products can get a little ratty cheap but aren't the worst

"Required" for very long runs yes. Still preferred over unbalanced for short or medium runs whenever possible/practical.

The more important point when choosing gear is that the devices with the combo balanced/unbalanced jacks tend to be higher quality than the ones that ONLY have unbalanced connections. In the similar way that the bluray format suggests you'll get a lossless HD master vs the CD format which is usually the volume war hyped version. There are exceptions.

And there's nothing wrong with a proper unbalanced connection with a proper (not too long) cable (not draped over a power cable) when you have vintage gear to connect.

I think the CD/BD comparison is potentially confusing for people. Balanced cables are to illiminate noise, mastering choices (ignoring sampling theorem debate) are something else altogether and don't relate.
 
Getting audio in/out of the computer is done with what's called an audio interface.
USB, firewire, or thunderbolt to connect to the computer. Audio jacks (in and out) to connect to the audio system.

I'm not interested in going into a computer and doing all that rigmarole. I have a Marantz (7700, if memory serves) as a pre-pro, and it's quite credible in the audio department. But, it has only one set of multichannel audio inputs, and I have three quad converters. My idea is to have each one output to an analog to HDMI converter, then use the HDMI as an input to the pre-pro.

There are some cheapo unbalanced analog to/from HDMI interfaces available.
They seem aimed at the consumer marker (that doesn't realize there are better products available) and the HDMI connection can be prone to copy protection gone wrong.
All of the ones I've seen are, at best, stereo audio and NTSC/PAL video. No multichannel anywhere. If you know of any, I'd really like to see what they are.

There are a number of little interfaces that feature 4 to 8 inputs and/or outputs in the $50 - $300 range.
If you want class A AD and DA converters (boutique audiophile level), Prism, Apogee, and RME are examples of interfaces with such converters. Add a zero to the above prices.
Let's face it, vinyl was great in the '70s, but this is almost 50 years later. 16 bit/44.1kHz will be more than adequate for the bandwidth and S/N of those beloved old records.
 
"Let's face it, vinyl was great in the '70s, but this is almost 50 years later. 16 bit/44.1kHz will be more than adequate for the bandwidth and S/N of those beloved old records."

Really?
 
I'm not interested in going into a computer and doing all that rigmarole...
Fair enough there. Although any of the old analog formats are literally magnitudes more of both fiddling around and expense.

I'm coming from the perspective of getting as close to the studio master as possible with no alteration or reduction of it. The computer offers happiness and light there for me. Someone else might be more interested in the user experience of old gear more than chasing the full sound of the recording in question. If that's your thing, I have no argument or comment. I'm also interested in preserving anything old (and possibly damaged) to the highest standards. I have interest in the old technology along those lines. But not the use experience.

All of the ones I've seen are, at best, stereo audio and NTSC/PAL video. No multichannel anywhere. If you know of any, I'd really like to see what they are.
It IS harder to find a budget interface with 6 analog outputs. Most of the budget models have 2 and then it goes up to 8 or more and a price to match.
These are a couple more budget (but still very pro and much higher quality than most consumer electronics) audio interfaces that have at least 6 analog outputs:
Focusrite Scarlett 6i6 $260 new $150 used
Presonus Audiobox 44vsl $200 new $120 used *** Sorry, this one only has 4 analog outputs! Would do quad for you though.
Moving into the "If you have to ask..." territory:
Apogee Element 46 $900 new (6 analog outputs)
Looks like you can get an Apogee Rosetta 800 (8 analog outputs, 8 analog inputs + some digital I/O) for $500 used. That's a pretty sweet price for this level of DA and AD converters. This thing went for over $2000 new!
Not even going to look at Prism right now...

Let's face it, vinyl was great in the '70s, but this is almost 50 years later. 16 bit/44.1kHz will be more than adequate for the bandwidth and S/N of those beloved old records.
Strongly disagree. No reason not to use 24 bit and every reason to use it! Consider that generation loss adds up. (Ever try to make too many copies of something?) Anything above 60KHz should be lossless for music program (assuming the AD stage was class A and on point if capturing analog). The nearest standard sample rate is 88.2k and the more common release format is 96k. If you're doing something like transferring vinyl to digital, the effort is in the prep and the real time analog capture. Would be foolish to set a switch to lower quality. Easy to click a button and make the lo res copies for your phone after the fact as an extra.

But again, I'm not after the experience of using the equipment. I'm after preserving the audio to the highest level possible (and exactly what came off the mastering desk whenever possible). I have respect for the old equipment and it's abilities that were successful but I'm very much not interested in preserving the artifacts or quirks. And again, I have no argument with anyone who is. Different goals.
 
First, although I appreciate your attempts at bringing me up to speed, I spent 50 years in the audio and video industries, 40 of them as an electronic engineer, so I didn’t just fall off the turnip truck. I understand how to stabilize an op-amp, but I’m not so hot at writing code.

I have an extensive collection of music, including 1,500 LPs and several thousand music files on my drobo NAS. Many of my files are surround and I enjoy the convenience of playing them through my Oppo 105’s Ethernet connection.

I also understand how sample rates and bit depth affect fidelity, and I’m aware of the limitations inherent in vinyl. I love listening to records, as well as CDs and other digital media. Sure, I’d love to go analog from disc to speaker, but that ship has sailed, at least for me. What I’m looking for is, as I noted earlier, is a way to integrate three quad decoders into a reasonable surround/video system. I don’t see adding a computer into the mix as meeting that goal. I’m pretty sure I still have the chops to design and build the sort of device I’m looking for, but if there’s one already on the market, I’d certainly rather spend the money on that instead of goung through the expense and effort of prototyping three units.
 
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