[Meyvn]

So is there a consensus? If I wired it similar to gerG's wiring, only my two amps were two Super-Ts, would that run K1000s balanced? If not, are there any benefits XLR cabling gives in and of itself, without balance, besides of course lack of wear on the jacks? Since I'm probably getting either the Zhaolu 2.0 or the D02 anyway, if I can't do balanced I might as well just run XLR cabling to RCA inputs if it's got any other benefits.

 

[Alwayswantmore]

Quote:

Originally Posted by Kees There is usually no such thing as balanced OUTPUT from a (power or integrated) amp (the amp that drives speakers).

This statement is not correct. There are a few out there (I use one to drive K1000s). This is a good link to info on balanced... http://www.balanced.com/faq/balanced.html

Meyvn, I did a search on Zhaolu 2.0, but could not find much in English. I assume that it is a DAC, and the XLR outputs are balanced outputs? If yes, then you have a balanced source. (Any specs?)

As stated by others, some members use balanced DACs to drive headphones via female XLRs (Search Lavry + balanced).

There are also some who have rigged custom cables and use a pair of headamps to create a balanced rig. See this link... http://www6.head-fi.org/forums/showthread.php?t=173449. If properly wired, output signals from the amps will be ungrounded balanced. So you end up with faster slew rate because of inverted signal driving the '-' leads. But, the input signal between the DAC and amps will (also) be ungrounded balanced. So you lose the noise reduction of grounded balanced normally found in balanced ICs (Bal ICs use three-prong XLR). And as someone already pointed out, the amps may not be matched (balanced amps are built to very tight tolerances).

Recommendation: Unless you already have the two amps, you may want to consider investing your money in a balanced amp or balanced DAC rather than an additional amp and a bunch of cables.

Bear in mind, I am not an expert on this. But I have some experience with balanced and I'm pretty sure this is right.

 

[lan]

Quote:

Originally Posted by Meyvn So is there a consensus? If I wired it similar to gerG's wiring, only my two amps were two Super-Ts, would that run K1000s balanced?

T-amps are different breed of amps. You need somebody who's done more research on the T-amp tech to say if it will even work.

 

[Kees]

Quote:

Originally Posted by Kees There is usually no such thing as balanced OUTPUT from a (power or integrated) amp (the amp that drives speakers). Alwayswantsmore: This statement is not correct. There are a few out there (I use one to drive K1000s). This is a good link to info on balanced... http://www.balanced.com/faq/balanced.html

Sorry, I read this link and I think my statement is correct. I also looked up the specs of your amp. Your Ayre v3 is a beautiful amp, built in DUAL MONO with two power supplies, thus preventing all distortion created by using common components between channels....(no common power and no common grounds) This is also sometimes called balanced, but there is no use of the inverted signal to the OUTPUT stages of your amp!
This is also the reason why people prefer to use two mono power amps to drive their speakers. In this way they can use the benefits of the balanced (three lead) ic's between their (balanced) pre amp and the mono power amps to cross the distance to their speakers. Thus they can place one power amp really close to the speaker it drives, and they only need a very short (1') lead of (always 2 lead non balanced and more vulnerable to outside distortion) speakerwire.
The same advantage goes for non balanced ic's here (although the advantage is a lot less), because the grounds shields the signal from outside distortion better than the two-lead speaker wire.

Also interesting in this discussion is this gadget from Eddie Current: http://www.eddiecurrent.com/ecdc.htm
This gadget actually creates an inverse signal that can be directed to two rca output terminals. Thus creating two (left & right) signal outputs (RCA) and two inverse signal (left & right) outputs (also RCA). With a simple cable adapter you could thus turn a non balanced output from a non balanced amp into a balanced signal (although without the grounds posibly. I am not shure about that aspect. I sent Craig an e-mail asking him to explain this, but he hasn't answered yet).

 

[Kees]

Quote:

Hello: gerG is one head-fi member who has used a balanced source and two unbalanced amps to create a balanced system. You may find the discussion interesting: [click me]

GerG uses Grace 901's, which have BALANCED outputs (inverse signal instead of grounds). The Graces are probably not dual mono. By using two amps in this setup GerG created a dual mono topology. Thus adding the advantages of not sharing grounds and power between channels, ON TOP OF the use of the inverse signal that is already delivered by the Grace.

 

[Alwayswantmore]

Quote:

Originally Posted by Kees ...but there is no use of the inverted signal to the OUTPUT stages of your amp!

"...keep in mind that the outputs of all Ayre amplifiers are balanced." Check out post 11 in this thread http://www6.head-fi.org/forums/showthread.php?t=177590. This letter was sent by the designer at Ayre.

 

[gerG]

Quote:

Originally Posted by Meyvn Airport Express (Toslink) - Zhaolu 2.0 (XLR out) - two separate unbalanced amps (RCA in) running one channel each. Balanced? Yes? No? If no, why not?

I vote yes, assuming that the XLR outputs from the DAC are balanced. I don't know why they would not be, but it is worth checking. I would feed it a sine wave and check the output. A true RMS meter would work best, but any A/C volt meter should do the job.

For the balanced setup, you will need some special cables. This includes balanced input cables for your headphones. You can't run a balanced drive through a single TRS headphone plug. Options are dual TRS or 4 pin XLR. Either configration will allow you to ground the headphone cable shield at the amp.

The Y cables can be either XLR to dual RCA, or XLR to dual XLR, depending on the amps and personal preference. In either case the ground is still connected, but it is carried in the shield in normal balanced cable fashion. Be sure to mark the cables for polarity, otherwise you will have a 50/50 chance of having the 2 sides out of phase.


gerG

 

[Kees]

Quote:

"...keep in mind that the outputs of all Ayre amplifiers are balanced." Check out post 11 in this thread http://www6.head-fi.org/forums/showthread.php?t=177590. This letter was sent by the designer at Ayre.

In my honest opinion Charles Hansen is only stating that you can run a headphone from the outputs of an Ayre amp as long as it is cabled with four separate wires, because if you use the normal 3-wire configuration you would short the two separate ground outputs. I think in his book "balanced" means dual mono = separate grounds, separate power: all components from the left channel separated from the right channel (Which is VERY good and adds an enormous amount of SQ). And of course it will work just fine that way, and he will still call his amp "fully balanced" (rightly so by his book, and the book of most if not all other manufacturers) even if he does not feed an inverse signal to each of the "grounds" posts of his amp.

Quote:

Originally Posted by Meyvn Airport Express (Toslink) - Zhaolu 2.0 (XLR out) - two separate unbalanced amps (RCA in) running one channel each.

I think there are three different definitions for "balanced" each used for different situations and easily confused.
1. A balanced amp: meaning dual mono topology. Also needed to propagate balanced input to balanced output if it is a pre amp. Any power amp that has balanced inputs and dual mono topology will be called balanced.
2 Balanced interconnects (3 pin XLR). A way to connect two devices with balanced wires: using three leads per channel. One ground and two balanced signals: signal and inverse signal. This way the signal can be transported over much greater distances because it is stronger and less vulnerable to distortion. Originally used in professional studios and such.
3. balanced headphones. Cabling headphones with separate ground wires for each channel and using the ground wire to carry an inverse signal.

To do the latter you need an inverse signal to come from your amp. If you don't use an amp with a balanced headphone output you cannot propagate an inverse signal to your headphone cable. Where would it come from? Even a balanced amp, but with an ordinary phones output jack would NEVER feed in inverse signal to the grounds of the jack, because in that way you would feed two different "inverse signals" to one shared grounds wire.You would have to somehow connect an incoming inverse signal (from your DAC for instance) inside your amp to the "grounds" of your output jack to get it to the driver of your phones....But that inverse signal would not be the inverse signal of the (amplified) output signal of the amp. So it would have to be amplified too. Easier would be to amplify the signal and then inverse-duplicate it. This is what Eddy Current does in the EC/DC. But straight out of an ordinary phones jack from any amplifier one can never get an "inverse signal" needed to drive your phones in truly balanced mode.
Dual mono: yes (and might very well be a considerable improvement I don't doubt). Truly balanced: no, I honestly don't think so.

 

[Alwayswantmore]

Quote:

Originally Posted by Kees In my honest opinion Charles Hansen is only stating that you can run a headphone from the outputs of an Ayre amp as long as it is cabled with four separate wires, because if you use the normal 3-wire configuration you would short the two separate ground outputs. I think in his book "balanced" means dual mono = separate grounds, separate power: all components from the left channel separated from the right channel (Which is VERY good and adds an enormous amount of SQ). And of course it will work just fine that way, and he will still call his amp "fully balanced" (rightly so by his book, and the book of most if not all other manufacturers) even if he does not feed an inverse signal to each of the "grounds" posts of his amp. I think there are three different definitions for "balanced" each used for different situations and easily confused. 1. A balanced amp: meaning dual mono topology. Also needed to propagate balanced input to balanced output if it is a pre amp. Any power amp that has balanced inputs and dual mono topology will be called balanced. 2 Balanced interconnects (3 pin XLR). A way to connect two devices with balanced wires: using three leads per channel. One ground and two balanced signals: signal and inverse signal. This way the signal can be transported over much greater distances because it is stronger and less vulnerable to distortion. Originally used in professional studios and such. 3. balanced headphones. Cabling headphones with separate ground wires for each channel and using the ground wire to carry an inverse signal. To do the latter you need an inverse signal to come from your amp. If you don't use an amp with a balanced headphone output you cannot propagate an inverse signal to your headphone cable. Where would it come from? Even a balanced amp, but with an ordinary phones output jack would NEVER feed in inverse signal to the grounds of the jack, because in that way you would feed two different "inverse signals" to one shared grounds wire.You would have to somehow connect an incoming inverse signal (from your DAC for instance) inside your amp to the "grounds" of your output jack to get it to the driver of your phones....But that inverse signal would not be the inverse signal of the (amplified) output signal of the amp. So it would have to be amplified too. Easier would be to amplify the signal and then inverse-duplicate it. This is what Eddy Current does in the EC/DC. But straight out of an ordinary phones jack from any amplifier one can never get an "inverse signal" needed to drive your phones in truly balanced mode. Dual mono: yes (and might very well be a considerable improvement I don't doubt). Truly balanced: no, I honestly don't think so.

Thanks Kees. IMO it would be valuable for the Headfi members to come up with a clear definition of balanced and make it a sticky thread. Just for the heck of it I'm going to run this by Ayre one more time to get their input.

 

[Alwayswantmore]

Got a response from Charles Hansen, Founder and Designer at Ayre. What follows is edited down to the facts...

Q. Head-fi's definition for BALANCED OUTPUTS includes 'an INVERTED signal being sent to the '-' leads for each channel'. Can you please clarify that Ayre's output signals are inverted?

A. Yes, all Ayre power amps are fully balanced, including the outputs. Even if you send it a single-ended input signal the outputs will be balanced (equal and opposite).

Best regards,
Charles Hansen

 

[Kees]

Great! Now we know for shure. I'm sorry that I made you doubt this in the first place. My suspicions of the output of the Ayre not having an inverted signal were wrong. I apologise for that.
(leaves me with another intriguing question though: how do cross-over filters in a speaker deal with this?????? They should be able to filter the inverted signal to be the exact counterpart of the filtered signal.....but only if there is an inverted signal.)
I fully agree with you that is is time to put an end to all the confusion about driving "balanced". Especially because I see people starting to invest in projects that are bound to fail beause of a misunderstanding. The initial post in this thread being a prime example of that. (Sorry Myvn, I don't want to discourage you in a nice project. The setup you propose may sound realy good, but it cannot have the benefits of the inverted signal, because it simply is not there....)
I suggest that we start gathering all info we have on this subject and then sort it out and make one final description. I already have studied a truckload of it. Some very sensible, some too technical for me to understand and a LOT of plain nonsense and sales talk.
Maybe I'd better start another thread for that, and ask some knowledgeable people to help me out. I know there are a lot of those around here.
Another point that is clarified by the answer from Charles Hansen is: You don't need balanced input to get balanced output...It can (and often will) be created in the amp itself. So there is no need for a balanced DAC.
Saves some $$.

 

[mulveling]

Kees, I believe you are the one who misunderstands Mevyn's proposed system. He's not talking about cobbling together a dual mono amp - he's talking about making a dual stereo one. Put two stereo amps together - dual stereo! One stereo amp amplifies R and R inverse, the other amplifies L and L inverse. Dual differential drive. The he'll recable the headphones to 4-point termination - except the K1000 already has this so he won't need to recable those. The proposed source already outputs signal, inverse, and ground for each channel. Where do you think the inverse signal is getting lost?? It's there all along. All he needs is adaptors and cables to patch it all together. It's very much like using one fully balanced headphone amp.

 

[Kees]

Thanks for explaining. I got lost where Meyvn stated that het wanted to convert XLR to RCA. Normally (in the standard XLR-RCA cable) this is done by just "losing" the inverted signal....Reading his first post it was not clear to me that he wants not to just convert XLR to RCA, but to actually split them in two RCA's, one with signal and one with inverse signal. Difficult soldering job, but possible I guess.
Now I understand where the inverted signal comes from. Sorry if I messed things up, I was just concerned. Thanks again for pointing this out to me.