Hi.
I am looking into the possibility of getting a CD Transport and some come with the choice of BNC or RCA output and some just RCA.
Is one type of connection better than the other?
Should I let this colour my judgement when choosing which ones to audition?
Thank you.
Roger
Hi there, BNC (Balanced) generally cost more and is the industry standard in music studios. The main reason however for this is the need for much longer cables, in this situation, BNC is said to be best. I personally have always used RCA connectors on my cables as the distance between source and preamp is virtually nothing. It is said that when using RCA you will not get as pure a signal. I think the quality of the cable being used and the distance between connections will also play a big part in this. NDS much like my CD555 only has RCA or DIN connections so if you went BNC you would need an RCA to BNC or DIN to BNC if such a things exists, this in itself would then compromises the said benefits of BNC. My focus would be to spend as much as you can on a quality interconnect relative to the cost of your NDS
Not sure about it being balanced?
Some XLR cables are balanced and popular in studios.
With the choice of RCA or BNC , on a digital signal, I would say it is more to do with impedance matching.
BNC cables, in hifi, are usually 75ohm cables.
This isn’t really possible with RCA plugs.
However, RCA is very ubiquitous in hifi.
I use a BNC cable between Audiolab CDT 9000 and my ND555. Very happy with that.
No. A good quality transport with RCA, will be preferable to a poor quality transport with BNC.
Primare make a very well reviewed CD transport, even though it doesn’t have BNC.
Don’t forget optical is also an option.
I have a Meridian 200 CDT into my NDS through a Harmonic Technology Platinum Digital RCA-RCA.
Sounds great when I need to spin a CD.
And if you compare to a ripped version via the UPnP input, very difficult to differentiate.
I would have it on a Harmonic Technology Magic Digital, which are great, if I used it more.
The 200 CDT, over the last 25 years, has been used with a Pink Triangle DAC (Dual DAC7 with the rare 24-bit filter) then ND5XS, ND5XS with NP5XS, NDS with NP5XS, NDS with 555DR, NDS with dual power supplies on Socket 1 & Socket 2).
Not correct.
Not balanced and are not standard in studios, however as stated above , XLRs are.
Impedance is the issue.
Just avoid adapters if any sort.
Choose one and get appropriate leads.
BNC has a characteristic impedance of 50 or 75 ohms and locking bayonet connector, both advantages over RCA. For SPDIF it should make no difference whether you go RCA or BNC if only spanning a few feet. SPDIF is a ‘slow’ signal and impedance/cable reflections become an issue when the frequency gets much higher into VHF/UHF spectrum.
Use BNC where it’s available. If your chosen transport only has RCA use an RCA to BNC cable.
The comment above about balanced connections for long cables applies to analogue XLR connections so I think there is some confusion there.
Agree, BNC and balanced are not the same thing, not remotely.
The balanced form of SPDIF is AES/EBU @110 ohm. there are almost the same except a few bits in the bit stream that the experts say can cause trouble if you try to connect with pro-equipment in a studio. but that never happened to me.
I’d say BNC and AES/EBU both have a reliably excellent sound quality if the impedance standards are met. you can use longer cables with AES/EBU. On the other hand as antenna cables are often 75-ohm BNC its easy to find a matching cable at low cost when you need one (unless you are a cable-snob :-))
RCA can sound equally good but varies more in my experience.
Had similar dilemma on how to connect Innuos Pulse transport to my NDS. I checked directly at Chord on their recommendation on RCA-RCA vs RCA-BNC in case of Chord Signature TA. I learned both connections would be excellent with no difference in sound. I went for RCA-RCA with no regrets. There is one issue however, if you are using Fraim. When you place NDS on Fraim, the RCA socket in NDS is placed very much against the back leg of Fraim. The space is very limited. You either need to strain and bend the cable or you need to swivel the Fraim leg a bit. Neither is ideal. I went for the second option, as straining cables is never good idea.
By coincidence I was looking at the spec for the s/pdif transformer used in the ndac a couple of weeks ago.
75 ohm and 110 ohm.
I wondered about the 110 ohm.
In theory a BNC is better because it maintains a 75 ohm characteristic impedance, which is the optimal CI for SPDIF coax (unbalanced). Phono plugs and sockets can’t achieve this simply by the limitations of the phono plug and socket geometry. However in practice this is likely to make minimal difference. SPDIF as a low cost interface and forgiving consumer specification.
What I would avoid on permanent setups are adapters, such as phono to BNC adapters and such like.
There are professional versions of consumer SPDIF, called AES3 (some refer to it as AES/EBU).
AES3 comes in two variants, balanced and unbalanced. Balanced uses IEC60958 type I interfaces, and has a CI of 110 ohms. AES3 unbalanced, uses the AES-3id standard and uses 75 ohm unbalanced coax, using the BNC connector. Electrically this is interchangeable with SPDIF
Thank you to everybody for your responses and the useful information.