Unbalanced Interconnect length...

chops

chops

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Some of you might know that I have upgraded from my Emotiva XPA-2 Gen 2 amp to a beautiful pair of Odyssey Audio Stratos monoblock amps.

Anyway, I've known for some time that these amps do not utilize true balanced inputs, they are just convenience XLR's tapped into the standard unbalanced RCA connectors. That said, many owners of Odyssey amps claim that unbalanced interconnects actually sound better. This is all fine and dandy except for the fact that I need a 30 ft run of cable to reach from the XP-20 to the Stratos amps.

I've never run unbalanced cables that long other than in car audio, and that was usually 17 ft to 20 ft at most, and with an AudioControl line driver up front right off of the head unit to boost the head unit's preamp voltage (usually 2v t0 4v) up to 9.5v rms (13v peak).

Considering the XP-20 has a max output of 7v (nearly 15v or so around clipping which I would never run my system that hard), I think that I should probably be fine running 30 ft of cable in the house.

My question is, what are your experiences running a good length of unbalanced interconnects in your systems? Did you find one brand or series better than the other?


Since the majority of my cables are Wireworld, I think I'd like to keep with them, and most likely upgrade some of them as well along the way.

Many thanks in advance!

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I had issues with a couple of sets of unbalanced cables, one BJC, and the other Zu Audio. I had hum with amp wattage >25 watts with my very sensitive Zu Druid speakers. Same speakers with BJC Balanced cables into a balanced amp (DIY Aleph J) was silent.

As I made more DIY single ended amps, and played with my dads old MC60 mono locks, I ended up getting a transformer based XLR-RCA box from Jensen, and 1m RCA interconnect pair. Worked perfectly. Something you might consider if you end up having trouble with RCA interconnects.
 
For long RCA unbalanced interconnects (and 30feet/10 meters is long) use a coax with a very heavy braided shield. The Blue Jeans Cable, LC-1 is one example, but the major bulk cable manufactures have other good coax cables.
A bigger problem is powering the distant units from another AC circuit.
 
I would first try the Blue Jeans cables and determine if they work ok in your situation. If not, then consider some of the other options recommended.
The problem with unbalanced cables is that the wire can act like an antenna, picking up unwanted noise along the way. It gets worse the longer the cable. But if you cannot hear any noise when you try it out, you should be good to go.
In the worse case scenario, if you cannot get rid of unwanted noise regardless what you do, I would consider moving to balanced-designed equipment.
 
I don't know why I didn't mention it in my first post, but the whole reason for asking about long unbalanced connections vs balanced is mostly due to the fact that our house has some kind of grounding issue, or at least this room does.

When we first bought the house a couple years ago and I quickly installed my system on the first day, I was running the NuPrime STA-9 amps for about a week, running a 1m balanced IC to them from my Schiit Freya+ preamp. The Freya+ utilized true balanced inputs/outputs, but the amps did not as they are like the Odyssey amps in that the balanced connectors are just wired into the RCA connectors.

Also, just like the Odyssey amps, the little NuPrime amps utilized grounded IEC connectors.

In contrast, the Emotiva amp I've been using this whole time uses true balanced inputs as well as a non-grounded IEC connector.

The Emotiva was always dead silent no matter what, but the NuPrime and Odyssey amps pick up buzz (not hum). I've always thought the buzz was coming through the ground in the house wiring, but if I disconnect the IC coming from the preamp, the Odyssey amps go dead silent, however when I did this with the NuPrime amps, they still had that buzz coming through but not as loud.

So now I'm wondering if that buzz is coming through the ground lead in the XLR cables, being that the preamp is balanced and the amp is not. This is what sparked up the whole idea of running standard SE IC's to the amps instead. Well that and the fact a lot of Odyssey owners claim that these amps sound better via standard SE IC's.
 
nicoff said:
In the worse case scenario, if you cannot get rid of unwanted noise regardless what you do, I would consider moving to balanced-designed equipment.
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This of course is not an option. These Stratos amps are not leaving this house.
 
Charles

Did you try a cheater plug on either the amps or the preamp to see if that would stop the buzz? This is not a really uncommon problem with using a balanced preamp and a SE amp. Not an ideal solution but it my give you an idea of where the problem is.
 
Jack said:
Charles

Did you try a cheater plug on either the amps or the preamp to see if that would stop the buzz? This is not a really uncommon problem with using a balanced preamp and a SE amp. Not an ideal solution but it my give you an idea of where the problem is.
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Hello Jack,

No, I have not tried that yet. I was looking around for the cheater plugs (I know I have a few of them), but they are M.I.A. Of course, I would only use them as a test. I certainly wouldn't leave them in the system. But yes, I know where you're coming from. I know you don't mean leaving them in.

This is also why I want to try some SE IC's. I have no doubts the XP-20 is equally excellent in both its balanced and SE outputs.

Since the amps are currently plugged (via the extension cable) into the same outlet as the source gear, the buzz is still present but much much quieter, it makes me wonder if I'm getting that noise specifically because I'm running a balanced signal to an unbalanced amplifier(s). Pretty much what you said I suppose, just in fewer words. LOL
 
That's been my experience with several combinations of that type. It's not always the case but more often than not. Tried a fully balanced W4S STP-SE into a Kismet a while back and had to lift the ground in that combo to eliminate a faint buzz. Also had it happen when I plugged a fully balanced DAC via XLR into a SE preamp and amp combo. Lifting the ground on the DAC solved the problem there. You may resolve it just by lifting the ground on the Pass preamp and that would be preferable. If you are plugging the preamp into some type of conditioner it will pick the ground back up there. Bones13's idea of trying the Jensen transformer may be a solution especially if you can find it on Amazon where you can try it out.
 
Oddly enough, it never crossed my mind to lift the ground at the preamp. That Jensen transformer seems interesting. Also, the Hosa GLT-255 ground lifter may work. But of course, all of these are just band aids and not truly addressing the issue.

Yes, it may look a bit hokey at the moment and I may not be getting the absolute best performance out of the amps right now, but at least my father's old homemade extension cable has reduced the "buzz" to where you can hardly hear it at the speaker. It's silent at the listening seat. I might as well just leave it as is for now until cooler weather gets here and my electrician friend can come over and install the dedicated lines.

Even if those devices mentioned work, I'd rather not have extra components in the signal chain if I can help it. Of course, as a last-ditch effort, I would go for on of those devices. And heck, for all I know, just running regular SE IC's from the pre to the amps could also solve the issue.


There is one other issue with this buzzing though, that for some reason I have failed to mention yet...

There's this loud buzz that comes through every once in a while no matter what outlet the amps are plugged into. It's the same volume regardless, and it sounds like something that's on a timer or something. It comes on loud (can be clearly heard down the hallway), runs for about 10 - 15 seconds, then turns off. It does this maybe once or two every two hours or so. In the late evenings, it seems to come on and stay on for several minutes, but then shuts off again.

I have no idea what it could be. When I first hooked up the stereo here on the day we moved in, I searched and searched all around the house for the source of that "timer" buzz, thinking if it could have been the irrigation timer, or the unused Fios box in the garage by the beaker box... Both unplugged now going on two years and that buzz still shows up. Maybe the water heater? I have no clue.
 
chops said:
This of course is not an option. These Stratos amps are not leaving this house.
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Well in that case, keep listening to their "buzzing" and don't make a fuss about it! :D
By the way, didn't Odyssey Audio the manufacturer of your Stratos go out of business?
 
nicoff said:
Well in that case, keep listening to their "buzzing" and don't make a fuss about it! :D
By the way, didn't Odyssey Audio the manufacturer of your Stratos go out of business?
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One way or another, the buzzing will be banished, and it won't be from changing out the amps. Part one of that banishment is the fresh order of BJC LC-1 cables that I just made.

And no, Odyssey is not out of business. Quite the opposite actually. You could have answered your own question with a 3 second Google search.
 
Funny none of that shows up when I do a Google search for them. Doesn't mention a single thing about them closing... Because they're NOT closed. And I too use the Opera browser.

Not to mention I was literally talking with the man just a week ago on the phone.




More importantly, back on topic...

I spoke with Galen of Belden ICONOCLAST yesterday, and for the money (conserving $$$ at the moment for a couple of extra upgrades including the dedicated 20amp lines for this room), he recommended going with the Blue Jeans Cable LC-1. So last night I ordered a 30ft pair. They'll be here in a couple of days.

I'll let you guys know what happens.
 
There are so many variants of balanced output and input circuitry that the course of action you are on is the correct one. Hook 'em up and see what happens.
 
I was thinking... If this works out as planned, should I also switch my Altair G1 over to unbalanced as well?

I mean, what's the point of running only one piece of equipment balanced if everything else is unbalanced, especially when I can use a 1m or less interconnect from the streamer to the preamp?

Plus, that would just be balanced circuitry having to convert over to unbalanced in the preamp anyway. Am I right in this thinking?
 
Some equipment work in an actual balanced function, meaning they receive the differential signal, and have circuitry for each hot and cold input (cold not being ground). This requires 4 signal paths from input to output, plus a ground plane. One of these units will work best, with balanced interconnects, when connecting to another truly balanced device.

Many “balanced” input or output plugs are the result of an internal transformer, or silicon circuitry creating a differential output, while the actual device runs as unbalanced. Other circuits just ground the cold leg, essentially making the XLR cable an unbalanced connection.

So, if your device is actual single ended inside, either connection would be the same.

Of course, as stated above, trying different things is the best policy, and part of the learning, and fun.
 
Bones13 said:
....

Many “balanced” input or output plugs are the result of an internal transformer, or silicon circuitry creating a differential output, while the actual device runs as unbalanced. Other circuits just ground the cold leg, essentially making the XLR cable an unbalanced connection.

...
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True that. Some manufacturers attempt to make their unbalanced products "look' as if they were balanced designs by adding XLR connections, yet they are not truly balanced designs. It is just a marketing ploy.
 
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