Question

tonyb

For you digital guru's. Whats the difference between a 75 ohm digital cable and 110 ohm ? I mean, I know the obvious difference, with 110 being used mostly in a balanced configuration, but is there any down side to using a 110 ohm cable as a coax digital where a 75 ohm cable should be optimal ?

I'm thinking maybe a bit more of that ringing in the upper registers using a 110 ohm ? Maybe lose some of the volume dial ? If 110 ohm is used mostly in a balanced system, why do they make them with rca plugs ?

To be more specific, I'm looking at a Acoustic zen absolute digital cable, which is 75 ohm, or their MC2 digital cable which is 110 ohm. Reviews of either are very good but the 110 ohm some are using in a coax digital in/output like you would a 75 ohm cable. Wouldn't there be some bad artifacts in the signal using a 110 ohm that way ?

OleBoot

Tony - In theory using the 110 ohm cable for and s/pdif connections is a no no. It may cause jitter and even bit errors over a longer run. Would it sound different/better/worse in normal use? Dunno, never tried it. However, back in the days of steam driven digital, there were a good number of cable manufacturers selling UTP cable for digital, which is completely out of spec as it's not even shielded. I tried some of this (memory fails me on brand - wanna say Tara Labs) and it sounded very detailed, and certainly not horrible, but it was a bit thin and weedy for my tastes.

tonyb

"Weedy"....now there's a new descriptive term. lol Thanks for your input pal, Kinda figured...

tonyb

Be nice Mikey.....sometimes we need to play nice in the sandbox, sometimes not. lol

SCompRacer

I thought the higher the number the better. Like it's better to have 110 dollars than 75? 220v gear sounds better than 120v gear?

steveinaz

Cable topology and connection method (therefore interface) decide the impedance. The wire itself is, well, wire. As long as the wire is capable of the transmission you're after, it'll work; though you still have to abide by topology "standards" such as shielding on coax.

Having said that, most analog IC's may or may not work well as a coax. I realize you're talking AES/EBU on XLR. I once tried a Kimber Hero as a digital coax---whew weee talk about tubby bass and loss of focus.

Tony---I'm telling you, try the $22 el cheapo Belden 1694A coax from Blue Jeans--I think you'll be shocked.

OleBoot

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

steveinaz

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

What are the cable topolgy standards for an amp's AC power connection?

Emlyn

steveinaz wrote: »

Tony---I'm telling you, try the $22 el cheapo Belden 1694A coax from Blue Jeans--I think you'll be shocked.

That's one of my favorites, especially at the price.

tonyb

I dunno Steve, I've had my fill of cheap cables already. Digital and analog. One thing I've found is when it comes to cables, there are certainly cheap cables that punch well above what their price point should dictate, but they still fall short to the better brands.

steveinaz

Trust me on this one hoss. And yes, you can cut off those cheesey colored collars BJ puts on their cables.

OleBoot

steveinaz wrote: »

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

What are the cable topolgy standards for an amp's AC power connection?

You have an off the wall sense of humor my man.

CoolJazz

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

Nahhh...just need an adapter!

I've always said if an adapter was available, some would plug headphones into an AC outlet!

CJ

CoolJazz

OleBoot wrote: »

Tony - In theory using the 110 ohm cable for and s/pdif connections is a no no. It may cause jitter and even bit errors over a longer run. Would it sound different/better/worse in normal use? Dunno, never tried it. However, back in the days of steam driven digital, there were a good number of cable manufacturers selling UTP cable for digital, which is completely out of spec as it's not even shielded. I tried some of this (memory fails me on brand - wanna say Tara Labs) and it sounded very detailed, and certainly not horrible, but it was a bit thin and weedy for my tastes.

Actually, UTP is well accepted as an excellent solution for AES. A BBC study rated it at the top. At normal data rates (redbook), AES only uses about 3mb/sec and normal Cat 5 is rated to 100. Very important is the very low spec for capacitance. You can stay within spec and run AES on Cat up to over a half mile.

Shielded does lower likelihood of other noise getting in, but you have to be in a really hostile, BAD environment to have that happen.

An actually, UTP used balanced, makes pretty darn good analog audio cable too from the same characteristics that makes it work well for high data rates.

I'd be suspicious of crossing up the use of 75 and 100 ohm designs.

CJ

tonyb

Given all that, why would a cable manufacturer make a digital 110 ohm cable with RCA plugs then ? What am I missing ?

[Deleted User]

RCA is an unfortunate standard. I READ what Oleboot is saying above
and stuck w/ 75 ohm. I did buy the BJ cable for my sub but am not
using it because of the "current" layout. Sounded good when I did use
it, but it was an upgrade from a throwaway cable.

oh, you said guru. please ignore.

CoolJazz

tonyb wrote: »

Given all that, why would a cable manufacturer make a digital 110 ohm cable with RCA plugs then ? What am I missing ?

Don't know of any answer for that one Tony. Using a different impedance than the design calls for doesn't make real sense to me. No doubt it'd lock to it, just would present more jitter due to the mismatch to the best of my knowledge.

And please excuse my closing comment typo. Should have said "75 and 110 ohm".

CJ

steveinaz

OleBoot wrote: »

steveinaz wrote: »

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

What are the cable topolgy standards for an amp's AC power connection?

You have an off the wall sense of humor my man.

You gave a totally unrelated scenario to the point I was making. I don't know if you're trying to be an ****, or you have some sort of point to make--but the interface determines the impeadance matching; then the cable design (topology) is optimized for that connection. There's likely wire that is used across many different cables, RCA, dig Coax, AES/EBU if it meets the spec's needed for the interface.

OleBoot

steveinaz wrote: »

OleBoot wrote: »

steveinaz wrote: »

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

What are the cable topolgy standards for an amp's AC power connection?

You have an off the wall sense of humor my man.

You gave a totally unrelated scenario to the point I was making. I don't know if you're trying to be an ****, or you have some sort of point to make--but the interface determines the impeadance matching; then the cable design (topology) is optimized for that connection. There's likely wire that is used across many different cables, RCA, dig Coax, AES/EBU if it meets the spec's needed for the interface.

Sorry, we posted around the same time and my post was in reply to SCompRacer's humorous comment. Mine was meant to be humorous also.

tonyb

Well, so far from what I can gather, using a 110 ohm with rca plugs is suppose to pass more digital data and is used in higher end gear. More than a 75 ohm coax digital cable that is. Still can't find the downside to that theory though.

OleBoot

tonyb wrote: »

Well, so far from what I can gather, using a 110 ohm with rca plugs is suppose to pass more digital data and is used in higher end gear. More than a 75 ohm coax digital cable that is. Still can't find the downside to that theory though.

I don't see that's the right conclusion. I could give a technical explanation as I understand it, but my knowledge about this stuff is self-taught and maybe wrong, and I fear the hammering I may get. Why don't you get on their website and email them from "confused in Chicago', act the dumbass, and see what they say? I would think that you are trying to get this used, but they don't know that. And, of course, share the answer.

steveinaz

Oleboot, my apologies---the typed word is sometimes misinterpreted; again I apologize.

vc69

@tonyb

My understanding is that 75ohm coax is for spdif connections. 110ohm coax is for AES connections (looks like a balanced connector). The interface itself is what determines the proper coax to be used.

check this link:
http://www.rane.com/note149.html
EDIT:
Eh... I see this has already been covered.

OleBoot

DSkip wrote: »

OleBoot wrote: »

As soon as I change the plug, I'm going to plug my amp into the washer outlet.

Monster has you covered:

On Friday nights, we drink the "good" wine, and I was mid sip when I saw this and...... you probably owe me about $1.

OleBoot

steveinaz wrote: »

Oleboot, my apologies---the typed word is sometimes misinterpreted; again I apologize.

Steve - no problem, I realized what had happened when I saw your reply.

txcoastal1

rednedtugent wrote: »

RCA is an unfortunate standard.

This is no BS, BNC should be the standard over RCA and F-type

OleBoot

txcoastal1 wrote: »

rednedtugent wrote: »

RCA is an unfortunate standard.

This is no BS, BNC should be the standard over RCA and F-type

For digital, AES/EBU theoretically ameliorates the noise problems that the RCA has, but still uses S/PDIF at the protocol level, which is also flawed. USB is a much better proposition on paper. But I don't have revealing enough equipment or enough experience trying this to say theory is proven in practice.