Should the whole system be balanced to make a difference?

Yes, that's a way manufacturers try to pull the wool over the eyes of the end-user.
Sometimes it's described in the manual as "an input that accepts a balanced signal", in other words, it has a built in balanced to unbalanced adapter

 

I think you've nailed it here pal.

 

Maybe to you, but then again...........

It was addressed to the OP.

Seems a lot of stuff here is "confusing" the issue, take for instance many of your posts above.

 

Actually, unbalanced can sound better than balanced in many cases. To balance a signal, you either need to go through a transformer or extra electronics both which can be degrading sonically. If you don't need to go balanced, I don't see much advantage to it.

Of course there are other advantages to running balanced besides minimizing noise. In most cases balanced signals are low impedance. Some unbalanced gear is and some is not. Preamps are more likely to have a lower output impedance than other sources. Tape decks and other sources are hit and miss. Those pieces are not expected to drive long lines, but they surely can if they've got low impedance balanced outputs.

For example, in a studio, a 2 track machine may go through up to or more than 100' of cabling by the time it gets to it's next amplifier. Replacing it with an unbalanced higher impedance output stage would not be a good idea.

Another advantage of balanced topology is that professional balanced gear outputs +4 db with a 0db signal on the meters while most unbalanced gear operates at -10 db. That's a 14 db difference and that's a very significant difference. In some cases a balanced output can actually overload the input of it's next stage.

 

Not necessarily.

In many cases, shields of unbalanced gear are telescoped. In other words, the shield is tied only on one end. I've even used small .01 caps in series with the shield at the other end of the cable. That way the shield does not create a ground loop, but is still effective for rf frequencies. In those cases the negative part of the signal can be derived from another location, and one that can provide lower noise.

What you don't want is current running down the shields of multiple components that have ever so slightly different ground potentials and are tied together. Those differences can be amplified and manifested as hum.

 

Hmmm coupling caps in the ground line sounds rather interesting...
Why would you want to pass on RF through ground? To utilize common mode noise rejection?

 

The cap keeps DC from passing, preventing ground loops, but allows any higher frequencies on the shield to pass to the ground, essentially snubbing them out.

That would happen had you connected the shield at each end, but that could also allow a duplicate ground path. So this allows the shield to still be effectively grounded at both ends except for DC.

You never want RF to sneak in. Best to eliminate it and snubbing it out keeps it from the console.

 

Completely agree!

Unbalanced/single-ended does not specifically mean high impedance, that's only sometimes true, but your point is basically correct.

And here's where things break down a bit. The pro reference level at +4dbu is pretty standard now, but have you seen balanced consumer gear running at a lower level? Basically -10dbu +6db because of the differential output? Sure wish the high-end consumer market would just stick with the pro standard, but it does make single-ended compatibility a but of a snag.

My above comment re: pretty standard comes from an age where we found +4dbm and +8dbm at studios, in particular where studios had to drive leased audio lines. Those lines were a dry pair equalized, often passively, for flat response to 15kHz, or 8kHz. Telco standard drive level was a nominal +8dbm, so that's what he hit them with. "dbm" went away when we stopped distributing power and started distributing voltage. Now it's dbu.

edit: adding this: In the late 1970s and early 1980s there was a recording console manufacturer that made some truly wonderful desks, even Telarc used them for their early recordings. You might read their name on a record sleeve, "Neotek". That manufacturer insisted that unbalanced line level wiring in studios was just fine. He built low Z line drivers, and everything did work quite well. That is, until you tried to interface one of those boards to a large studio complex with long lines and high-rise quality grounds (in other words, very poor). I had two of them in a large complex. We custom-built balanced interfaces for them, but all the in-studio wiring worked fine unbalanced. The wiring in studios would be considered long for a home, the inter-studio complex wiring would be considered extremely long for the home.

 

Common practice in gear designed for high RF environments. Yes, you want to pass RF to ground, but avoid an AC ground loop. But the caps aren't for DC blocking, there really isn't any at that point, they're to provide a low impedance path for RF, but high(er) for audio band signals. Other RFI techniques include series LC networks, ferrite beads, and bypass caps, all on audio lines. One of my clients is a radio facility with 8kW of RF radiating from a tower on top of the building. The building has an RF screen around it, but it's not perfect. I still can measure nearly 2V/m inside the building. Yeah, we do a lot of RFI proofing in there. Most audio distribution in the plant is AoIP, but there are a few analog circuits left. About 80% of the analog circuits are carried on unshielded Cat5, 20% on shielded Cat5. The few single-ended circuits are only a few feet and then hit a balancing amp (with RFI proofing).

 

It's humorous watching this thread metastisize when the OP's question was answered to his satisfaction early on the first page. It's evolved into the "recreational arguing" and knowledge muscle flexing which happens so often around here.

 

If there's a built-in balanced to unbalanced adapter, something that does an actual conversion, then the job is done correctly. If they imply the can accept a balanced signal...by unbalancing it, then they're basically deliberately misleading customers.

 

I always choose simplicity right up until that choice results in inaccuracy that might mislead someone.

If I've confused anyone, kindly let me know what the problem is and I'm happy to clarify, hopefully, simply.

 

I'm not sure if anyone has mentioned it, but a simple instrumentation balanced input is noisier (as in hiss) than a well designed single ended input. Not by a small amount either. A decent single ended input can easily achieve -120dBu, whereas a single op-amp balanced input with 10k input resistors will only manage around -100dBu. You *can* get to -120dBu with balanced, but at the cost of complexity. Or use an input transformer.

The real benefit of balanced is common mode rejection. With single ended, the coax screen takes the signal return, so any circulating power related currents find there way into currents in the coax screen - resulting in what is called a "hum loop". The trick to minimise that is (a) plug everything into a single distribution block to minimise currents in the equipment grounds and signal cables and (b) use short signal cable runs, and chose cable with the lowest screen resistance.

 

As I've stated in my OP, the only other component in my system that has a balanced input (and probably an output) is my Cary Audio SL-100 line stage preamp. Given the pedigree of the firm, I'd say if the input says "balanced" and the screen lights up as "Balanced" when that input is selected, I would bet it is balanced. Nothing else is though.

I have made up my mind a while ago, and a Modi Multibit is on order - and taking quite a while, I should note. As you and I agreed, I get the MB, you get the Modius, and then we'll swap for a while to see if one is better than the other. If I find Modius worth it down the line - I'll get one of those too, easy -peasy.

I haven't been following this thread because I've noticed new battles raging here, which I find rather pointless to follow considering I've made my decision a while ago.

 

Mentioned. But don't forget that balanced line drivers and input stages can operate at pro reference levels, which are 14dB higher, and still maintain 20dB or more of headroom. That puts the entire DR in a sweet spot above where single-ended operates. You pick up around 6dB of noise, then bump up the operating level 14dB, so the net result is 8dB lower noise.

If you use identical signal levels, then yes, single ended is quieter.

Input transformers are not a free ride.

Yup.

 

I figured....

Yes, we're still on for that!

Gotta come clean though - still haven't ordered the Modius, but I am going to! My problem as you know is I've gone nuts on 5 or 6 other audio purchases recently I am sorting through, but the Modius is on the short list and will be ordered very soon! On that note, I am really digging the two Accuphase power amps I have been auditioning, it's going to be tough to part with one of them.

BTW, there have been a few USPS purchases that have had inordinate delays recently, especially in the last few weeks. I've experienced the same longer than expected deliveries. One Gigabit switch I bought from and Ebay seller in NJ took 8 days from the time it was picked up from the sellers mailbox, and scanned into the USPS system. It was sent Priority 2 day.... so clearly USPS is having issues, might have something to do with.... well, never mind, don't want to start a sidebar.

 

Sorry. I thought there was actual interest in understanding this stuff.

 

Nope, I just got a reply from Schiit: unexpected delay with parts, may be a few weeks before mine is even built, and it has already been two weeks. Reading between the lines, "weeks" may turn into months.

 

No rush - seems I have nothing to exchange with you for now, anyways.

As to going a bit over the top with audio purchases - I hear you loud and clear. For this year, I had a resolution to buy nothing. So far, up to beginning of September, that "nothing" has included:

Kenwood KD 500 DD TT;
Pro-Ject The Classic BD TT;
Icon Audio PS2 phono;
NuForce STA200 SS amp (fried, returned);
Wharfedale 225 speakers;
NHT SuperOne 2.1 speakers;
Jico SAS and 2M Bronze styli;
A quad of NOS RFT EL-34's;
A pair of NOS Brimar CV4003's;
A pair of NOS Brimar CV4035's;
An upgrade of Lounge LCR Silver to Gold;
An upgrade of Copla to Silver;
A Lounge power supply unit;
An A-T tonearm auto-lifter and aluminum sub-platter for The Pro-Ject Classic;
A few interconnects and tube dampers;
And maybe some other odds and ends I can't even remember.

I'd say my "nothing" has not really been a success, and the year isn't over yet...

EDIT: Oh yes - and the Multibit on order.

 

Sorry, didn't mean to sound like an ungrateful bastardo. It's just that as a regular layman, I'm not very technical, so these intricate engineering-course-worthy explanations are somewhat too much for me, even though I'm flattered you think I'm smart enough to understand them.

 

Man people like to type a lot of stuff

Hey OP, it doesn't really matter if your whole system isnt balanced... you'll gain the benefit of unison and XLR grounding/noise reduction from the DAC, even if the end result from pre/amp speaker amp is not if you think about it right ? any noise or ground issues would be with the pre amp or amp then if there was gonna be.

ALSO most importantly, the modius has 2 different output stages, run the xlr and se into 2 of your pre inputs so you can swap between them. It's like 2 dacs in one. there is a bit of difference sound wise between them.

blah blah xlr blah blah blah se blah blah, this place is HILARIOUS

 

Well, if what you think you're providing is simplicity and clarity, more power to you!

 

You don't have to be technical to understand this stuff. What don't you understand? I can try to come up with an analogy that you can more easily understand.

 

Okay... I'm working on understanding the above dission and applying the information. Thank you for your input.

I currently own a Teac NT-505 DAC. It is a good DAC and has Preamp capabilities. It has XLR outputs and I plan to use the DAC as a preamp with ethernet streaming to the DAC on a soon to be purchased high quality power tube amp. A full balanced XLR path is a buying decision. I am certain that the power amp is fully balanced.

So... my confusion in reading the above, is how do I verify the fully balanced Teac DAC claim? Can I see it on the specifications? I do not own a balanced amp currently.

Teac NT-505 specs and claims:
Dual monaural circuit design and fully-balanced design A dual monaural circuit configuration is used throughout, from the power supply (including power transformers), to the D/A converters in the digital section and the analogue output stage. From the high-performance VERITA AK4497 D/A converters to the massive toroidal-core power transformers, each element is configured for single channel processing. This prevents mutual interference effects while reproducing a rich acoustic expressiveness. In addition, the analogue audio signals of both the left and right channels are processed in full balanced mode soon after the D/A converters all the way to the output terminal, contributing to an improved S/N ratio and extended dynamic range. This allows the fantastic sense of air that HiRes formats possess to be processed and conveyed without any losses.

Audio output XLR balanced

XLR × 1 pair (gold-plated) ​

Output level

Fixed (0 dB), fixed (+6 dB), variable, output off (selectable) ​

Maximum output level

2.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to fixed (0 dB))
4.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to fixed (+6 dB))
12.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to variable) ​

Output impedance

188 Ω ​

Audio output RCA unbalanced

RCA pin × 1 pair (gold-plated) ​

Output level

Fixed (0 dB), fixed (+6 dB), variable, output off (selectable) ​

Maximum output level

2.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to fixed (0 dB))
4.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to fixed (+6 dB))
6.0 Vrms (1 kHz, full scale, into 10 kΩ, when set to variable) ​

Output impedance

150 Ω ​

 

Some questions for you (see where I've numbered quoted text above)

1. Why is a fully balanced path a buying decision?

2. Why are you certain the power amp is fully balanced?

3. What part of "Dual monaural circuit design and fully-balanced design " is confusing to you?