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manisandher wrote:

This is very interesting and something that I have not noticed. Because I cannot double the clock frequency going into the Weiss AFI1, I have tended to ignore playing/recording 4fs files. But, I've kept the second AES/EBU wire attached nevertheless... because I didn't think it could make any difference. I will try unplugging it and determine whether or not I can hear a difference too.

Well, frankly I do not truly understand what that Weiss AFI1 does. I think this devise is bogus by a concept. Here is how I interested it: If you take Firewire of USB out of your PC then the other side of Firewire of USB shell be right in DAC, right next to the master clock on the DAC side. If your Firewire of USB devise have some kind of proxy box, with own PS and own clock, then I think it defeats all purpose.  I do not insists that I am right – I just think it is architecturally does not look kosher to me. You insist that Pacific shall run as master clock referent, OK, but the referent to what? To Weiss AFI1, right? Then you have a Firewire link to PC but Firewire does not care clock data – it is asynchronous.  So, my question would be – what manages the clock of your playing/recording software? Then you play/records then can you do it right to your Weiss AFI1 device? Will, the change of the Pacific clock trigger the automatic reset the sampling rate of your playing/recording software. The most important: when you sent from Pacific reference clock of 88K but play a file of 44K, outputting the stream to a third audio devise, then will you have the half-speed effect? If you do not have the same effect as reel tape of 15ips played at 9ips then your software is not truly slaved by Pacific/ AFI1 chain.

Anyhow, to mimic the problem that I describe do the following:

1)      Play a good analog source to line A of your preamp
2)      One of the outputs send to Pacific A/D
3)      Set Pacific  in 176/24  mode, dual-wire
4)      Send signal out of Pacific D/A to line B of your preamp
5)      Set the Pacific output (of whatever menace you have) to be identical volume to line A of your preamp
6)      Flipping  between the line A  and B of your preamp confirm that you have identical sound (or note whatever delta it would be)
7)      Now switch the Pacific into 44/24 mode, single-wire mode, without touching anything else.
8)      Note that this time that the output from line B of your preamp (across Pacific) will be slightly louder (let say 2dB, but I did not measured)
9)      Noted that the output from line B of your preamp (across Pacific) will be a bit brighter and flatter then the line A of your preamp. It will be no death of imaging and sound would be almost broken up – almost like from a computer voice.
10)   Now, unplug the second-wire and note the difference.  In my case the louder 2dB will be gone and the sound will be identical to what was in paragraph # 6 above. 

During this experiment the minor differences between 44 and 176, if you have any,  shall be discarded as the amplitude of the problem I descried above is much higher then the dealt between  44 and 176

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