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post #871 of 6360

of course chris. that's the idea.

 

you can get outstanding sq with some pro monitors and not pay hifi prices. I recommend genelec. of course that last 5% of pure pleasure cannot be had for hifi. that will cost $$$. 

post #872 of 6360
Quote:
Originally Posted by music_man View Post

of course chris. that's the idea.

you can get outstanding sq with some pro monitors and not pay hifi prices. I recommend genelec. of course that last 5% of pure pleasure cannot be had for hifi. that will cost $$$. 

The last bit of pure pleasure can be found in Las Vegas.
And that will cost you $$$
tongue_smile.gif
post #873 of 6360

yeah, no sh..... I have enjoyed a few evenings of debauchery. before I was married of course I mean.

post #874 of 6360
Anybody have any experience with the Arcam irDAC?

Not the old rDAC, the new irDAC, the one with the iDevice USB input.
I've never heard one, but I do like the idea of plugging an iPod or iPhone or iPad straight into it.

Anybody try this DAC to see how it compares soundwise with "the other contenders"?
post #875 of 6360
Quote:
Originally Posted by purrin View Post
 

This has nothing to do with Headroom or RSA "balanced" / bridged amps. We are talking about differential signaling, e.g. 2x3-pin line level XLR patch cables in pro/studio environments where long lengths are used, etc.

 

Whether the equipment is used in a studio or home environment was really not the topic of discussion. The issue being discussed was with the common practice of DAC manufacturers offering a balanced output option by taking shortcuts: 1) splitting the standard SE output with a cheap opamp splitter going into another two opamps for the differential drive; or 2) using a different set of op-amps (usually lessor quality, but higher output current than the SE opamp) for the balanced outputs.

 

Let's not bring up the Headroom or RSA definition of "balanced" again. Gives me a headache.

 

I follow you as to the above.  My assumption, perhaps wildly incorrect, was that most of these high end dacs would be using an I/V stage (e.g. http://www.twistedpearaudio.com/linestages/legato.aspx ), rather than a cap coupled output straight off the dac board, as is possible with at least some chips.

 

If the manufacturer is using different opamps for its se and balanced outputs, that certainly further complicates matters.  But I guess I don't see why the same principles that apply to gain stages in headphone amps wouldn't apply to a line or I/V stage in a dac?  (Again, happy to be educated if I'm grossly oversimplifying here?)  If, per the engineers at Benchmark, a push-pull output (or alternatively a bridged output) generally adds noise and distortion (excluding common mode) and raises output impedance, and has higher component cost, why is this sort of output at all desireable as compared to an equivalent se output if the anticipated use of the product is within a home where there is no benefit to CMR? 


Edited by skeptic - 3/24/14 at 10:48am
post #876 of 6360
Thread Starter 

I dunno. These things don't apply to me and I try not to think about these kinds of things. I use the SE outputs of my DAC into my SET tube amp (which obviously only takes SE inputs).

 

It helps to sells cables with expensive XLR connectors?

 

Now I did feel the PWD2 or Gungnir's XLR balanced outputs in to the Mjolnir (circlotron circuit) sounded 1.07% more resolving with better separation and space. Not significant enough detect the difference via blind AB (and yes I do like blind tests or pulling off trickaroos such as telling my ninjas when one thing when it's really the other to psych them out) or significant enough to change any of the rankings.

post #877 of 6360
Quote:
Originally Posted by Chris J View Post

Anybody have any experience with the Arcam irDAC?

Not the old rDAC, the new irDAC, the one with the iDevice USB input.
I've never heard one, but I do like the idea of plugging an iPod or iPhone or iPad straight into it.

Anybody try this DAC to see how it compares soundwise with "the other contenders"?

I have an rdac i bought mine in cloney audio and while i have not heard the irdac the store owner - Ivan tells me that is is a good stet up from the original rdac. Didn't it win loads of awards? 

post #878 of 6360
Quote:
Originally Posted by skeptic View Post

I follow you as to the above.  My assumption, perhaps wildly incorrect, was that most of these high end dacs would be using an I/V stage (e.g. http://www.twistedpearaudio.com/linestages/legato.aspx ), rather than a cap coupled output straight off the dac board, as is possible with at least some chips.

If the manufacturer is using different opamps for its se and balanced outputs, that certainly further complicates matters.  But I guess I don't see why the same principles that apply to gain stages in headphone amps wouldn't apply to a line or I/V stage in a dac?  (Again, happy to be educated if I'm grossly oversimplifying here?)  If, per the engineers at Benchmark, a push-pull output (or alternatively a bridged output) generally adds noise and distortion (excluding common mode) and raises output impedance, and has higher component cost, why is this sort of output at all desireable as compared to an equivalent se output if the anticipated use of the product is within a home where there is no benefit to CMR? 

Some companies use a plain old fashioned Op Amp for the SE output and a specific, purpose built analog integrated circuit for balanced output. The company "Analog Devices" makes a purpose built balanced output IC: SSM2142.
The guy from Benchmark may have had a bit of an agenda when he made these statements......
You can also argue that balanced outputs increase SNR.
And if the distortion is low enough, then the added distortion a balanced output creates is academic.
Or you can argue that a balanced amp a la Nelson Pass cancels distortion.
He's received a patent for his Super Symmetry design so it must do something.
Edited by Chris J - 3/24/14 at 2:54pm
post #879 of 6360
Quote:
Originally Posted by Chris J View Post


Some companies use a plain old fashioned Op Amp for the SE output and a specific, purpose built analog integrated circuit for balanced output. The company "Analog Devices" makes a purpose built balanced output IC.
The guy from Benchmark may have had a bit of an agenda when he made these statements......
You can also argue that balanced outputs increase SNR.
And if the distortion is low enough, then the added distortion a balanced output creates is academic.
Or you can argue that a balanced amp a la Nelson Pass cancels distortion.
He's received a patent for his Super Symmetry design so it must do something.

 

Agreed that SuSy is a different story.  (Sadly, I don't have the technical background necessary to fully appreciate the why of it.)  But if you look at Mr. Pass' technical summary article, you will note that he essentially agrees with the Benchmark guy in so far as suggesting that the 3 traditional balanced approaches either perform worse than, or at best, equal to, ordinary 2 channel single ended designs.  https://passlabs.com/articles/super-symmetric-amplification

 

I understand Pass Lab's SuSy patent recently expired and that's why Dr. Gilmore, Spritzer and company have now released gen2 SuSy dynahi and dynalo diy designs.  I am not aware of any dacs using that topology, but I certainly would be interested in an EE's perspective as to how beneficial this is in low power applications and whether we are likely to see a proliferation of SuSy output stages in commercial dacs in the future.  

post #880 of 6360
Quote:
Originally Posted by Chris J View Post

Or you can argue that a balanced amp a la Nelson Pass cancels distortion.
He's received a patent for his Super Symmetry design so it must do something.

I'm pretty sure that's too low a standard.  There are lots of bad patents out there that do very little that's useful.  If you're willing the pay the legal fees you get a patent on pretty much anything, useful or not.  

post #881 of 6360
Quote:
Originally Posted by StefanJK View Post

I'm pretty sure that's too low a standard.  There are lots of bad patents out there that do very little that's useful.  If you're willing the pay the legal fees you get a patent on pretty much anything, useful or not.  

I was being sarcastic.
Super Symmetry is, in fact, one mechanism by which distortion can be reduced.
post #882 of 6360
Quote:
Originally Posted by skeptic View Post
 

 

Agreed that SuSy is a different story.  (Sadly, I don't have the technical background necessary to fully appreciate the why of it.)  But if you look at Mr. Pass' technical summary article, you will note that he essentially agrees with the Benchmark guy in so far as suggesting that the 3 traditional balanced approaches either perform worse than, or at best, equal to, ordinary 2 channel single ended designs.  https://passlabs.com/articles/super-symmetric-amplification

 

I understand Pass Lab's SuSy patent recently expired and that's why Dr. Gilmore, Spritzer and company have now released gen2 SuSy dynahi and dynalo diy designs.  I am not aware of any dacs using that topology, but I certainly would be interested in an EE's perspective as to how beneficial this is in low power applications and whether we are likely to see a proliferation of SuSy output stages in commercial dacs in the future.  

 

We're way off topic here, but I don't see any reason why you can't use this in low power applications: driving headphones or used as a pre-amp building block.

The kicker is, it is a balanced in, balanced out configuration, i.e. no point in using it in an SE or SE out configuration, its advantages are lost there.

post #883 of 6360

Agreed that we're getting out into left field at this point, and I promise I won't belabor the point any further, but just fyi - in the new SuSy dynahi's and dynalo's, the circuits are actually se or balanced in, but only balanced out.  No input transformers required.  Still slowly churning my way through the NEETS materials hoping that some day I'll be educated enough to puzzle out how this actually works.    

post #884 of 6360
Thread Starter 

Another circuit that is balanced or SE in, but balanced out is the circlotron or "Cross-FET" as implemented in the Mjolnir amp. There's lots to read up on that.

post #885 of 6360

Which makes me curious how they're doing SE out on the Ragnarok.

 

Maybe they're just stashing a Magni inside.

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