Digital connection frustrations

HiFi Dave

Novice Member
Probably an old gripe, but why are there so many different digital connections, when what is being sent is the exact same signal is it not?
I have a Panasonic DP-UB9000 Blu ray player with HDMI, optical and spdif digital outs. My Jay’s Audio DAC 2 Signature has BNC, AES/EBU, RCA and I2S digital inputs. What fun!

Update: the DAC has optical input but I hate optical connections and don’t have a long enough cable. They keep falling out! Whoever designed optical connections should be shot lol 🤦🏻‍♂️
 
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Helix Hifi

Well-known Member
The signal is digital from my understanding. On or off. Ones and zeroes.

However many swear to usb, simply because the sound is better.

As many swear to optical vs coaxial. I would always use optical against coaxial. Because coaxial is prone to ground loop. Annoying sound from the speakers. Not be confused with speaker hiss. This normal. Although more expensive amplifier are more silent. Ground loop is high buzzing sound.

If the optical cables keep falling out, you either have cheap ones.

Get some Forrest AQ optical cables. They don’t fall out.

BNC/AES/EBU, are balanced cables. If am not mistaken. Though I think XLR are balanced.

Some think XLR are better. RCA are unbalanced. Most amplifiers have RCA inputs.

Why don’t try and see what sounds best for you.

I believe coaxial can transmit higher sound resolution then HIDM, coaxial.
 

Helix Hifi

Well-known Member
I meant coaxial can transmit higher sound resolution then HDIM, optical.

Though I’m not certain. I use quality shielded RCA cables.

Never heard balanced cables. But I have heard optical, coaxial.

I think I like optical the best. Difficult to tell exactly.
 

Itsthesmell

Active Member
Im feeling your frustrations also. I've bought an expensive amp that has its own DAC. It has HDMI (for TV ARC only), 2 COAXIAL, 2 OPTICAL, 1 USB B (PC only). So, connecting my CD player to the rca has good sound, but the coaxial digital is a superior sound, but coaxial won't pass SACD/DSD audio through it, the only way to get DSD to the amp is RCA or PC USB, but RCA isn't as good so if I buy an SACD player will I be wasting my money?
Then I heard PS Audio have an SACD player for sale, but it will only pass the SACD digital audio through its l2S output. Its a piss take.
Someone said try a Sony SACD player as it might send the audio down the coaxial and so today I bought a used on from eBay. Comparing the RCA and Coax the coax is superior for ordinary CDs, RCA is superior for SACDs, I bet its not as good as l2S though, which I don't have. Grrr
 

k-spin

Active Member
Sony SACD players won’t send the high resolution (DSD) signal via digital coax, just the standard CD (16 bit/44kHz) signal.
 

DT79

Distinguished Member
Sony SACD players won’t send the high resolution (DSD) signal via digital coax, just the standard CD (16 bit/44kHz) signal.
That’s the same for all SACD players. It’s a copyright/licensing thing.
 

HiFi Dave

Novice Member
Im feeling your frustrations also. I've bought an expensive amp that has its own DAC. It has HDMI (for TV ARC only), 2 COAXIAL, 2 OPTICAL, 1 USB B (PC only). So, connecting my CD player to the rca has good sound, but the coaxial digital is a superior sound, but coaxial won't pass SACD/DSD audio through it, the only way to get DSD to the amp is RCA or PC USB, but RCA isn't as good so if I buy an SACD player will I be wasting my money?
Then I heard PS Audio have an SACD player for sale, but it will only pass the SACD digital audio through its l2S output. Its a piss take.
Someone said try a Sony SACD player as it might send the audio down the coaxial and so today I bought a used on from eBay. Comparing the RCA and Coax the coax is superior for ordinary CDs, RCA is superior for SACDs, I bet its not as good as l2S though, which I don't have. Grrr
They should all have to have at least one common connection. It makes no sense to do otherwise because it devalues all hifi having so many different connection methods. A manufacturer might 'force' you to buy their other component but equally they will not buy them for incompatible components from other manufacturers, so they will lose as much as they gain. Just use the best and leave it at that. If only the world was sensible grrr.
 

HiFi Dave

Novice Member
I got no digital sound out of my 4k blu ray player via optical. I did get sound via optical from TV (via HDMI from player to TV) but now I am getting horrible digital noise instead of disc audio. I feel like giving up!
 

Khazul

Well-known Member
I got no digital sound out of my 4k blu ray player via optical. I did get sound via optical from TV (via HDMI from player to TV) but now I am getting horrible digital noise instead of disc audio. I feel like giving up!

Check setting menu in TV - it probably has an optical out audio mode selector somewhere.

As for why so many different connections, well they all came to be a long time ago to serve different physical and/or signalling purposes at the time. While some of them in the early days may have been derived from each other at a signalling level (and later made signal compatible), they may have been designed to serve a different purpose at the physical level (balanced AES vs unbalanced coax SPDIF for eg - AES is used in the professional world where 24 bit over long cable runs was needed vs the 16 bit SPDIF of the time). In some case, same connector may be used, but the underlying signalling is different - stereo TosLink vs 8 channel ADAT for eg.

HDMI is a different thing again to fulfill the needs of digital video which also needs to carry multi-channel audio and these days in both directions include compressed and uncompressed formats at various sample rates as technology has improved on the years. Like other mechanisms, that has evolved a lot over the years as well to support higher bandwidth (resolution), device control, audio return from TV etc.

These days add USB 2 as well because that provides the means for full control of a device from computers as well as much higher sample rates and bit depths.

IIS was only ever intended to to be for on-board communication between a microcontroller and a DAC chip, but because it offered a clocking advantage over SPDIF, then people decided it could be useful for feeding audio data into a DAC from outside the device, so some devices ended up with IIS connectors (of which there are many as there is/was no standard for this).

Over the years some of the earlier and similar signalling has been unified (SPDIF, TosLink and AES), but still they want to keep connectivity with existing devices.
 
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DT79

Distinguished Member
But why does that help the license holder?
Because taking the digital stream over SPDIF, which has no authentication protocols, would be an easy way to rip it to file or copy to to some other media.
 

DT79

Distinguished Member
I got no digital sound out of my 4k blu ray player via optical. I did get sound via optical from TV (via HDMI from player to TV) but now I am getting horrible digital noise instead of disc audio. I feel like giving up!
Are you connecting them to a DAC? It may be the same issue in both cases - ensure the output is set to PCM in the settings. It’s probably defaulting to Dolby Digital or ‘bitstream’ (output the raw audio codec for decoding downstream).
 

Mark.Yudkin

Distinguished Member
That’s the same for all SACD players. It’s a copyright/licensing thing.
The S/PDIF (and TOSLINK) standard is specified to a specific bandwidth, which is lower than the SACD's requirements.
 

steve iow

Active Member
Probably an old gripe, but why are there so many different digital connections, when what is being sent is the exact same signal is it not?
I have a Panasonic DP-UB9000 Blu ray player with HDMI, optical and spdif digital outs. My Jay’s Audio DAC 2 Signature has BNC, AES/EBU, RCA and I2S digital inputs. What fun!

Update: the DAC has optical input but I hate optical connections and don’t have a long enough cable. They keep falling out! Whoever designed optical connections should be shot lol 🤦🏻‍♂️
Totally agree, broke one on my av amp now broken one on my new Marantz pm 7000n those little black flaps aren’t fit for purpose, and yes I was being gentle when fitting the cable they are crap
 

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