TOPIC: Coaxial digital output to AES3 input

Hi there,

I am using minidsp SHD for my active speakers. As the speaker accepts AES3 digital input, I suppose it requires a 110 ohm impedance cable . If I want to connect SHD coaxial digital output to the Speaker, what type of cable should I use? RCA to AES 110-ohm cable or RCA to AES 75-ohm cable or using a AES 100-ohm cable with a RCA 75ohm to 110-ohm transformer(I don’t know if this exists but I can find BNC 75-ohm to 110-ohm transformer.

Many thx

So basically what you're saying is you are going to have a coaxial RCA on one side and an AES XLR connector on the Other side... if that's the case it really will not make a difference , you can use either or ...depending of course how long of a run we're talking. if just a few feet, it won't make a difference either way, Both of them ..75ohm or 110ohm, are very similar in terms of how they were developed and they are virtually interchangeable at the protocol level. but at the physical level they specify different electrical signaling levels and impedances, which may be significant in some applications.

AES/EBU can safely be run using 75-ohm coaxial cable. BUT...If you're going to go over 100 feet I believe you need to use the 110- ohm Cable.

Ehcchan wrote: The SHD (Studio) has a XLR digital output already. Why would you use the coaxial RCA jack??
You just need a suitable XLR -> XLR cable. No transformer/adapter should be required or needed. Active monitors with digital input should have a feed-through output jack. Then on each speaker you would select which channel (left or right) to pull out of the data stream for that particular monitor.

Dave.

Hi Dave, thank for your reply. I am currently using SHD but not SHD Studio. SHD has 2 RCA digital outputs only (each has 2 channels). I want to try SHD studio as I suppose its XLR digital output may be better for active speakers. However, even if I bought SHD studio, I would use linear power supply.

Ah, yes indeed. I read your post and assumed (incorrectly) you had the Studio unit.
Sorry about that.

Dave.

Hi there,

I've just tried to connect my SHD using its RCA digital output (1&2) to a AES/XLR input of my active speakers (digital-digital connection. However, it is not working, simply no sound/signal. The same cable was used to connect SHD's RCA audio output to my active speakers (analog-analog connection) and was working fine. I think I am using a wrong cable but what cable should I use? I know that I need a SPDIF to AES3 cable, but what's the difference with my current cable (RCA to AES3).

Ehcchan wrote: Most likely you need to perform a setup change in your active speaker to switch inputs. Most active speakers are not smart enough to auto-switch.....and you wouldn't want them to anyway.

Dave.

Thank for your reply. Yes, I have configured my active speaker to accept digital input. I checked both my active speakers and AES source are working properly. I think either the cable or the digital output from SHD has problem. Any suggestions?

I've found from my active speaker web page, it said that the correct way with an S/PDIF output, is by means of an impedance transformer. Where can I get it?

Does your active speaker process 96khz sampling rate???
Which active speakers are we talking about here? Make? Model?

An impedance transformer would be preferred, but it's not the problem you're describing. A simple RCA/XLR should get the system working even though the loading would not be optimal.

Dave.

This is what you need: www.amazon.com/Hosa-CDL-313-Coaxial-SPDI...U-Link/dp/B000068OGS

Then string one speaker to the other.

Or you should have just gotten the SHD Studio in the first place. I go SHD studio straight to my JBL 708p and then coax to a DAC to my single massive sub.

Hi Dave,

My active speakers are Dutch & Dutch 8c, it supports 96k hz sampling rate, the same output from SHD. I am sure I have all the correct configuration for the active speaker and I have tested it working properly with a direct connection to a digital source.
It simply no sound when I use RCA/XLR cable with SHD's digital output.

Yes, solution may be either an impedance transformer costs less than US$100 or a SHD studio costs $800.

Ehcchan wrote: Before purchasing anything, I would contact Dutch and Dutch and ask them about the voltage levels required at the AES input. The AES standard specifies quite a bit higher voltage than S/PDIF, but usually a system will still operate.
If you have an oscilloscope or another DAC, you could verify the output from the SHD on the coax jacks.

Dave.

jsimon7777 wrote: FYI, the 708p's don't terminate correctly if chaining them per the recommendation. If you go from a standard AES source to one speaker and then via the Digital Through to the other speaker, your source sees a 55 ohm termination, not 110 ohm. However, it still works okay.
Some other digital input monitors do this as well. That's why I was asking ehcchan about his specific speakers.

Dave.