[alexhl]

The Offramp5 is also good. Keep in mind that there will be a MK2 hiface soon and eventually will be modded by JK

 

[drez]

I think what you will find with transports is that synergy, as in the level and type of jitter in the SPDIF signal, SPDIF voltage and risetime will affect the how you perceive the performance of a transport.
 
John Darko has tested a lot of DAC and transport combinations and for him, the AP works better with some DAC while the mk3 works better with others.  I think AP can sometimes have too low of certain types of jitter for some DAC's to sound natural.
 
Different DAC's use different SPDIF receiver chips, a lot nowdays use WM8805, some still use DIR9001, not sure which other chips are used.  These chips operate differently to each other, some are more succeptible to SPDIF voltage, produce different jitter at the output and generally differ in the way they manage jitter.  With my last DAC I could change SPDIF receiver and preferred the sound of a less sophisticated receiver with my transport (DIR9001) as it sounded less forward.  With a different transport, or a different DAC, this receiver might sound better.
 
So the performance of any one transport with any one DAC can vary because of numerous factors.  Personally I wouldn't be surprised if the computer used plays a role also.  This is supported by the varied impressions of the AP with different DAC's we have seen in this thread and elsewhere.

 

[sphinxvc]

Quote:

^Sorry, I've been a little worn out recently from burning in and integrating two S/PDIF converters. It can be a fun process and the results potentially gratifying, but its also distracting when experimenting with a system one is basically happy with. Anyway...
 
The Wavelink HS has a balanced fullness in the midrange. In comparison the AP2 pushes its mids slightly forward, something which is easily apparent with female vocals where the voice to a small degree recesses those sounds surrounding it. The forward mids of the AP2 also brings a slight warmth overall (not to say that its warm) and that's not bad thing, but a bow to personal preference more than anything else.
 
With high frequencies the Wavelink is extended and detailed, even over the AP2. It excels with transients and has a nicely developed decay, bringing out a wonderful tonality with acoustic instruments. Its upper and lower bass is tauter and less reserved than what I recall with the MK3, and the AP2 holds the middle ground in this respect. 
 
Take my comments on the MK3 with a grain of salt as its been out of my system for 3 weeks, but I consider the AP2 a small improvement over it, and the Wavelink a small but significant improvement over the AP2. I could be possibly be happy with either of the other two, but not without a period of remorse.

Thanks, Pigmode, for the impressions.  
 
Quote:

I think what you will find with transports is that synergy, as in the level and type of jitter in the SPDIF signal, SPDIF voltage and risetime will affect the how you perceive the performance of a transport.
 
John Darko has tested a lot of DAC and transport combinations and for him, the AP works better with some DAC while the mk3 works better with others.  I think AP can sometimes have too low of certain types of jitter for some DAC's to sound natural.
 
Different DAC's use different SPDIF receiver chips, a lot nowdays use WM8805, some still use DIR9001, not sure which other chips are used.  These chips operate differently to each other, some are more succeptible to SPDIF voltage, produce different jitter at the output and generally differ in the way they manage jitter.  With my last DAC I could change SPDIF receiver and preferred the sound of a less sophisticated receiver with my transport (DIR9001) as it sounded less forward.  With a different transport, or a different DAC, this receiver might sound better.
 
So the performance of any one transport with any one DAC can vary because of numerous factors.  Personally I wouldn't be surprised if the computer used plays a role also.  This is supported by the varied impressions of the AP with different DAC's we have seen in this thread and elsewhere.

 
I'm curious to see what kind of effect these transports are having on FR.  As in...which one has the least impact in FR.
 

 

[drez]

Quote:

Quote:
 
I'm curious to see what kind of effect these transports are having on FR.  As in...which one has the least impact in FR.

Funny thing is these are all bitperfect apparently, yet people perceive frequency shifts

  Something more complicated than just more/less jitter is happening IMO.

 

[Rdr. Seraphim]

That would be an interesting test, and I've wondered myself what differences would be uncovered since clean power would be available to the entire system, not just the clocks.  
 
The new AP2 PS seems to be a bit late in arriving, but hope to see it this next week. 
 
Quote:

Awesome (+ pompom too).
 
So I don't recall, were you running it with normal usb power?  
 
When it arrives, I'd consider sending my AP2 + AQVOX your way for a comparison.
 

 

 

[Rdr. Seraphim]

See bold italics. This brings us back to "what is really going on" with transports. What are the mechanisms involved with these things? How could too low jitter be detrimental to the music? Or do ultra-low jitter transports level the playing field with DACs so that the DAC and the receiver, combined with the analogue output become the limiting factor? 
 
Quote:

I think what you will find with transports is that synergy, as in the level and type of jitter in the SPDIF signal, SPDIF voltage and risetime will affect the how you perceive the performance of a transport.
 
John Darko has tested a lot of DAC and transport combinations and for him, the AP works better with some DAC while the mk3 works better with others.  I think AP can sometimes have too low of certain types of jitter for some DAC's to sound natural.
 
Different DAC's use different SPDIF receiver chips, a lot nowdays use WM8805, some still use DIR9001, not sure which other chips are used.  These chips operate differently to each other, some are more succeptible to SPDIF voltage, produce different jitter at the output and generally differ in the way they manage jitter.  With my last DAC I could change SPDIF receiver and preferred the sound of a less sophisticated receiver with my transport (DIR9001) as it sounded less forward.  With a different transport, or a different DAC, this receiver might sound better.
 
So the performance of any one transport with any one DAC can vary because of numerous factors.  Personally I wouldn't be surprised if the computer used plays a role also.  This is supported by the varied impressions of the AP with different DAC's we have seen in this thread and elsewhere.

 

 

[Rdr. Seraphim]

I believe that if you were to measure any of these devices regardless of the transports, the FR would be typically ruler flat 20 - 20K (or more depending on the sampling rate). A rather crude analogy would be measuring most SS amplifiers--on the bench under strictly resistive loads, they measure very flat. However, putting them in the real world with real loads/interfaces, then differences begin to appear. 
 
Quote:

Quote:

Thanks, Pigmode, for the impressions.  
 
 
I'm curious to see what kind of effect these transports are having on FR.  As in...which one has the least impact in FR.
 

 

 

[pigmode]

I'm convinced jitter is just one part of the equation. It makes for good ad copy but doesn't hold up in terms of consistency in the real world.

 

[slim.a]

The interactions between the transport and the DAC are indeed far more complex than many people imagine.
 
As an example, one can read stereophile's measurement of the Empirical Audio OR4 here: http://www.stereophile.com/content/empirical-audio-ramp-4-usb-format-converter-measurements
The OR4 has slightly higher jitter (in the high frequencies) than the Halide Bridge. Yet when both units are run as USB transports, there significantly less jitter at the DAC output when using the OR4 as a transport.
 
There might be other parameters at play that explain (further) the differences we hear when listening to different transports.

 

[Rdr. Seraphim]

X2 - I agree. It appears that AP has set the jitter standard for most S/PDIF transports (except this from MSB, a $10K option: http://www.msbtech.com/products/galaxy.php), so we need to look elsewhere for other contributing mechanisms that make a difference. 
 
Quote:

I'm convinced jitter is just one part of the equation. It makes for good ad copy but doesn't hold up in terms of consistency in the real world.

 

 

[slim.a]

Quote:

This brings us back to "what is really going on" with transports. What are the mechanisms involved with these things? How could too low jitter be detrimental to the music? Or do ultra-low jitter transports level the playing field with DACs so that the DAC and the receiver, combined with the analogue output become the limiting factor? 
 

Your last point is very interesting.

In my system, I have the possibility to connect the DAC with the headphone amp either through regular RCA or through ACSS/current mode (those who have audio-gd gear should be familiar with these terms).
After spending many months with my set-up, I had come to think that both type of connections were more or less equivalent (when using good quality cables on both) with slight differences between the two methods.

After upgrading to the AP2, and especially with the AQVOX, I have found that there is far more distortion on the RCA type of connection. Whatever the AP2+AQVOX combination is doing, it seems that my system is not able to fully keep up with increased speed. Also, it also possible that that very small distortion was already present. Who knows?
In the grand scheme of things those are subtle differences but they do seem to exist as far as I can tell.
 
So, indeed, the analog output might turn out to be an important factor. Most probably it is a combination of the digital receiver, impedance, filter, DAC type, grounding, analog stages... that govern the results of transport/DAC interactions.
 

 

[DaveBSC]

Quote:

The interactions between the transport and the DAC are indeed far more complex than many people imagine.
 
As an example, one can read stereophile's measurement of the Empirical Audio OR4 here: http://www.stereophile.com/content/empirical-audio-ramp-4-usb-format-converter-measurements
The OR4 has slightly higher jitter (in the high frequencies) than the Halide Bridge. Yet when both units are run as USB transports, there significantly less jitter at the DAC output when using the OR4 as a transport.
 
There might be other parameters at play that explain (further) the differences we hear when listening to different transports.

Yep, jitter seems to be only one factor. For what it's worth, Steve said that the OR5 with the USB regulator cuts jitter in half compared to what Stereophile measured with the OR4.
 

 

[Rdr. Seraphim]

Steve's getting there on the jitter specs.  

 BTW, do you own the OR4 or OR5? 
Quote:

Yep, jitter seems to be only one factor. For what it's worth, Steve said that the OR5 with the USB regulator cuts jitter in half compared to what Stereophile measured with the OR4.
 

 

 

[Audioexcels]

Quote:

I had occasion to hear tonight the Hiface MK3 battery to AP2 + (hub powered with a 5 volts battery (a small DIY circuit) to avoid to use the wallwart coming with the hub).
Was a quick test ...
 
We was 4 ... they asked me to do stop after 10 sec on the hiface. I consider AP much better ... not the same level or performance period.

http://www.digitalaudioreview.net.au/index.php/news-blog-and-showcase/john-darkos-blog/item/344-a-ramble-through-digital-audio-transports
 
"How does the Audiophilleo compare to the JKSPDIF?  I get asked this question a lot.  I've tried them both with a wide array of budget DACs over many, many months.  There really isn't that much to separate them sonically.  I could happily live with either (in the long-term) but I distinctly preferred the JKSPDIF with the Metrum Octave - it seemed to bring out more elasticity and tame some of the glassiness."
 
You did say the AP2 was beaten by the Xonar ST until you made that hub setup.  Maybe the same is holding true about the hub setup vs. battery power with these USB converters?

 

[Audioexcels]

Quote:

I believe that if you were to measure any of these devices regardless of the transports, the FR would be typically ruler flat 20 - 20K (or more depending on the sampling rate). A rather crude analogy would be measuring most SS amplifiers--on the bench under strictly resistive loads, they measure very flat. However, putting them in the real world with real loads/interfaces, then differences begin to appear. 
 


 

Exactly.  How can one explain the science of anything audio based that shows flat FR, but in the system we are subjectively evaluating, the two components sound vastly different.  I like to listen with my own ears rather than explain something that can be explained, but is pointless when we are subjective listeners, not objective listeners.