What is this? And is it something worthwhile?

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gvl_guy

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I saw this thing on Amazon. Not exactly sure what it is.

I'm very familiar with old school quad stuff and recently started getting into multi-channel discs. I have a totally vintage system other than an Oppo BDP-83 for the discs.
Screenshot_20210322-190701.png

I have no computers connected to my system. I don't make discs to play in the Oppo. No idea what I'm doing. But I'd love to get quad material from sites to download (usually FLAC files that my Oppo doesn't handle).

So what exactly is this and what can it do? Seems like some type of decoder? Maybe a way to stream stuff via bluetooth? Seems kinda inexpensive.

https://smile.amazon.com/dp/B08CNK2VZ2/ref=cm_sw_r_cp_apa_fabc_1JGANJ1R35RR7DEK5GPW
 
So what exactly is this and what can it do?

It looks to me like its main purpose is to convert digital multichannel audio (via the optical/coaxial or HDMI inputs) into analog multichannel audio (via the RCA outputs). These types of conversion boxes can be handy if you want to use a new HDMI-only device with an older AVR that pre-dates HDMI. I use a similar unit to play FLAC files from my HDMI media player through my Marantz 4070 amp.
 
searching for "rh-699x pro" shows various listing on the +- 110$ price tag, not too bad for what it seems to do.
 
Well, i dug out a bit about this unit:

1) RH-699X Pro has two releases, one without PC USB playback (Standard version), one with (USB Sound Card version).
So far the units WITH pc usb playback seems to be only in China, elsewhere there's no mention of pc usb playback. Newer unit doesn't show one more usb port, so it should be plugged on the front... unless they're using older photo. Stereo aux in with pair of RCA sockets.

2) There is a very similar unit with model number HD951BT, that one has a USB-B port on the back for pc usb playback AND a USB-A port on the front for thumbdrives. Stereo aux in with one 3,5mm jack..

The specs for both units are the same. In the typical chinese way, f/r is up to 20k but the units can decode 192... go figure...

Both units +- same price.

Photos of the HD951BT

s-l1600.jpg




s-l1600.jpg
 
As a MCH external DAC it does a lot of work, since it can interface not only with PC but with a lot of other sources. If from 2.0 to 5.1 is enough, it seems a good way to "update" a 4.0 vintage system with a full digital connection set. Not bad.
 
Looks like a basic little HDMI connecting audio interface. A very standard type of product. Your HDMI AV receiver has an HDMI audio interface built into it. (Think of an AVR as a combo product.) This is simply a stand alone audio interface that connects over HDMI.

There are a lot of inexpensive little devices nowadays that offer a lot of bang for the buck.
That said. Three strikes right out of the gate. HDMI, only unbalanced analog connections, and sold by Amazon.

I'd be wondering about any copy protection gone wild that often comes with HDMI devices.
Unbalanced analog only? Seriously?

Like a lot of stuff from the last 10 years, the DACs and the analog preamp support circuits should be a solid level of just fine. Could be a lot of bang for the buck for $150. I'd shop for an inexpensive USB or firewire audio interface first FWIW. Something that has the expected balanced/unbalanced 1/4" combo jacks (and maybe some XLRs) and connects with USB, firewire, or thunderbolt. If you're strictly a listener and never record anything, you'll have some inputs you'll never use but the rest of the thing will still feel like a better deal.

It's all fun in theory. There might be better deals or better choices but this is still probably at least solid and functional. (Assuming none of the HDMI lock out shenanigans anyway!)
 
Having the 5.1 analog outputs as well makes something like this a natural with older surround receivers, or (horrors) to feed a matrix encoder. I'd like to see a full spec sheet on this little device. Exactly what, aside from DTS and Dolby Digital, can it work with?

Hard to tell, the best shot i had was to looking in ali express and fount that page that has a whole description, chinese market style

97.65US $ 37% OFF|Professional 5.1 channel audio decoder USB U disk lossless music playback Bluetooth 5.0 fiber coaxial audio decoding 6 CH output|Digital-to-Analog Converter| - AliExpress

But... for looking at what's the real stuff under the cover, i think i've found the board for the 699:

57.58US $ 21% OFF|DTS AC3 5.1 Audio Decoder Board PCBA Converter DAC 4K*2K HDMI Extractor Switcher Digital SPDIF Audio USB Home Theatre Bluetooth| | - AliExpress

DTS-AC3-5-1-Audio-Decoder-Board-PCBA-Converter-DAC-4K-2K-HDMI-Extractor-Switcher-Digital.jpg_Q90.jpg_.webp

Since the board is named

dec51bt_v3

googling for it shows a couple of videos, rather old, so maybe referring at the first version.
 
For sure only AC3 & DTS, plus the classic stereo format (mp3, flac....).
As usual with chinese stuff, what is written BIG is what it does; if it is not written BIG, it doesent.

In that case, no Atmos, no Dsd, not TrueHD or MasterAudio. Maybe if someone can understand what are and do the big chips on the board we may have a better idea.
 
Similar interface WITHOUT fancy LCD (=just the DAC part) and analog Aux In, here too two version of the same stuff:
HD851BT
RH-688X
 
Just ordered what they are calling a 4th generation unit, board labeled RH-688X4. Hoping this gets the Quadio Doobie Brothers out of the box.

4K HDMI 5.1 Audio Decoder Bluetooth 5.0 DAC Lossless For DTS U Disk RH-699X tps

Upgraded Functions:

- It only takes three seconds to start playing and decoding.
- Support U disk to play any music. Output sound through optical fiber and coaxial or 5.1 interface.
- Support folder and file browsing and playing, you can choose any song to play.
- Larger screen display with light brown acrylic glass, protecting your eyes.
- Multiple buttons on the panel to support the operation of all functions.
- Support six output modes, including 5.1, 5.0, 4.1, 4.0, 2.1 and 2.0 channel.
- You can fine-tune 15dB volume per channel.
 

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Found the unit on eBay; 4K HDMI 5.1 Audio Decoder Bluetooth 5.0 DAC Lossless For DTS U Disk RH-699X tps | eBay
Quadio Doobies is my first digital Quad... I’m all analog, never owned a DVD or Blu-ray player.
I'm new to anything not "old school" (quad LP's, 8 tracks, reels.) But i recently bought a used Oppo player -- an older model so it wasn't very expensive. (BDP-83) It does a fantastic job decoding pretty much every disc into my vintage receiver. The only thing it can't do is play FLAC files. It seems that's what people "trade" mostly to play quad/5.1 channel stuff that's been uploaded/downloaded. But I'm okay with that. I thought maybe this unit would be able to do that.
 
Would not something like this be redundant for someone with an HDMI v1.4 Oppo (BDP-103 and higher) with ARC capability? I find it difficult to believe that the DACs in this inexpensive device can be as good as those in the Oppo units. If they are, more power to them.
 
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