Romy the Cat wrote:

I find it very covenant to run analog source and then be able to switch the source signal passing across Pacific A/D-D/A where both D/A and DAW run from the same Pacific’s A/D clock. In fact it is so convenient that I asked myself if it worth for me to run Pacific from my Preamp outputs and just save to my DAW some of my most precious LPs and Tapes.

manisandher wrote:

Have you tried this yet? If so, in percentage terms, how close do you think the digitized signal is to the original analog signal? (This is something that I'm hoping to try myself at some point, but I don't have a good analog source right now.)

Nope, I did not try AD any better source then FM with Pacific. I did try it with Lavry Gold, the result was so-so but I knew that I did it very badly and I was not going for “best” results. I need to rewire everything to do it “properly” and it is not very inconvenient for me. Also, I do not have a lot of motivation to convert LP or Tape to high-resolution files. If I have an AD permanently plugged into one of the outputs of my preamp, as I proposed above then it might be a game changer…

Also, there was recently an interesting observation that I am not sure how to interpret. When I had Lavry Gold AD and Lavry Gold DA plays into each other and compared the sound of my FM from SU-1X direct with the sound of AD-DAW-DA chain then I heard absolutely no difference. With replacing the Lavry Gold AD-DAW-DA to Pacific AD-DAW-DA I did observe a minor difference, not improvement of courses…

manisandher wrote:

Related to posts on other threads, I recall noting that the Model Two's clock frequency is slightly off 44.1 KHz. With the Model Two in Master mode, the Weiss AFI1 reads the clock frequency as something like 44.08 KHz (I'm not in the UK right now, but will check the exact freq. when I get back). However, when the Model Two is switched to 48KHz, the AFI1 reads the clock frequency as exactly 48.00 KHz. Romy, perhaps your Model Two exibits the same behavioiur? If so, could this 0.05% difference account for the anomalies that you're hearing between the Model Two and Lavry? (Of course, this should only be the case when the Model Two is in Master mode.) To test this, you may want to record and compare a piece at both 44.1 (x1/x2) and 48 (X1/X2). I know the latter will cause you a lot of pain, but keep reminding yourself that it's in the pursuit of knowledge, and you should pull through OK... [do you allow smilies on this site?]

Romy the Cat wrote:

The problem is that I detect that if I record in 44/24 or 88/24 in single-wire mode but the second wire is connected from Lynx to Pacific (and the line is muted by Lynx mixer) then I do have worsening of sound quality. The sound auditable improves when I plug out the second, not used line.

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

Romy the Cat wrote:

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.

Romy the Cat wrote:

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

manisandher wrote:

And I can indeed replicate this effect... but only with my RME FF800 and not with my Weiss AFI1. With the FF800 (slaved to the Pacific), changing the Pacific's wordclock does indeed change the speed of any audio/video being played. (Going further, using the FF800's internal Direct Digital Synthesizer (DDS) clock, I have 'total' control of the speed of audio/video.) This suggests to me that software can indeed be slaved to a firewire device. However, I cannot replicate this effect with the Weiss AFI1. Here, the player/recorder software seems to dictate the frequency. If the frequency down the chain (with the AFI1 or Pacific as Master) is different to that of the software, then there is simply no sound produced.

Interesting. If so then I would say that Weiss AFI1 defeat the purpose of running the Pacific as Master Clock. What would be even more interesting to see if the sonic benefits of having Pacific as Master will manifest itself while Weiss screw up the software slaving. It is possible that despise the AFI1 does not do slaving-transparency but it still would sound very reasonable. Why knows…

manisandher wrote:

For now, I have tried to hear a difference in the sound by simply unplugging the second AES/EBU cable whilst listening to a 44.1/88.2 file in single-wire mode. I'm not sure how closely this replicates step #10 of your procedure, but I cannot hear a difference (in either level or sound quality) with the second cable in or out... Have I totally misunderstood the issue here?

Actually you did not misunderstand the issue the issue but it turned out that I was an idiot. As soon I got your email I decided to do it again. This time I very much as you do not hear any difference. I did it very many times and there was no difference. I absolutely remember as I heard a huge worsening of sound as soon I plug the second digital line in. Upon the further experiments I learned that this problem manifest itself ONLY if I do not mute this second digital line on my Lynx mixer. I was under impression that switching the Lynx and Pacific in single-wire mode shall make them doing not even feel the second line, not it is not how it works. Anyhow, explicitly muting the second line via the Lynx mixer addresses all problems. I thought I did it but I did not realize that it was a very critical step. I wish the Pacific would be smarter with not-used line rejection and I wish the Lynx mixer lines would be more isolated.

Anyhow, some I figure out how to use it the Pacific is rehabilitated, in fact it become a relatively comfy multi-format processor. I just need to find for it a location what I would be sit higher in my rack as it is troublesome to  bend my body to read it display and to push the button with my big toe finger.

Whoever follows the Pacific Microsonics  threads, or whoever use Pacific know that both Models one and two have an interesting idiosyncrasy: at maximum sampling rate, when Pacific runs in dual-wire mode, the clock runs at half speed. It does not make since to have A/D running at 176K but clock at 88K. So, it would be responsible to ask: what is the purpose to slave DAW if the processor does not care the right sampling reference?

I was under this presumption for a couple year but last might I suddenly come to me and I concluders that it does not matter. Let me to explain my rational. Be advised that I have no specific knowledge in the field or consulted with knowledgeable people, this is just my take that is based strictly upon common sense, at least the way how I understand the common sense.

There are two arguments that I would like to bring up:

1)  Pacific Microsonics was designed and built by very knowledgeable people who very much knew what they did. Furthermore Pacific was made in “no expense spare mode”, so it is not such a thing the some functionality was not implemented because they wanted to keep it cheaper. So, if Pacific teal decided to output a half-speed clock at in double-wire mode then they feel that it was how it needs to be done.

2)  What is double-wire mode? It is what one wire cares a half sampling rate and another wire cares another half. The double-wire is not stereo and not dual mono.  In stereo we have two different signals that fluctuate by own rules cared in two wire. In dual-wire AES/EBU each wire cares a half of the very same signal and a half of sampling frequency. In dual-wire digital both wires are running from the very same clock and if the signal in dual-wire divided not identically (I do not know if it is possible) then the fluctuation clock marks across the wires are absolutely identically as there is just one clock for both wires. So, what is the clock slaving? It is some king PLL driven phase-locking of one clock to another clock.  The key in here is to get reference and to trace the rate of change. Since the master clock is only one for both wires then the slave clock might look for the sampling marks in any of the wires ion case it reads samples from AES/EBU. In case the clock reference delivered to slave clock by own 75-ohm BNC word clock cable this cable can care ANY sampling frequency as long phase-wise it reflects the masterclock.

I think this is why Pacific Microsonics  Model 2 does not output 176K clock and Model 1 does not output 88K clock. In fact I do not think that Model 2 even has 176K clock and Model 1 has 88K clock. They most likely have 44K and 48K (1X) clocks and multipliers. So, it is very possible that my concern about the half/clocking in dual-wire mode with Pacific was just my own self-inflicted worry.

Romy the Cat wrote:

Whoever follows the Pacific Microsonics  threads, or whoever use Pacific know that both Models one and two have an interesting idiosyncrasy: at maximum sampling rate, when Pacific runs in dual-wire mode, the clock runs at half speed. It does not make since to have A/D running at 176K but clock at 88K. So, it would be responsible to ask: what is the purpose to slave DAW if the processor does not care the right sampling reference? I was under this presumption for a couple year but last might I suddenly come to me and I concluders that it does not matter. Let me to explain my rational. Be advised that I have no specific knowledge in the field or consulted with knowledgeable people, this is just my take that is based strictly upon common sense, at least the way how I understand the common sense. There are two arguments that I would like to bring up: 1)  Pacific Microsonics was designed and built by very knowledgeable people who very much knew what they did. Furthermore Pacific was made in “no expense spare mode”, so it is not such a thing the some functionality was not implemented because they wanted to keep it cheaper. So, if Pacific teal decided to output a half-speed clock at in double-wire mode then they feel that it was how it needs to be done. 2)  What is double-wire mode? It is what one wire cares a half sampling rate and another wire cares another half. The double-wire is not stereo and not dual mono.  In stereo we have two different signals that fluctuate by own rules cared in two wire. In dual-wire AES/EBU each wire cares a half of the very same signal and a half of sampling frequency. In dual-wire digital both wires are running from the very same clock and if the signal in dual-wire divided not identically (I do not know if it is possible) then the fluctuation clock marks across the wires are absolutely identically as there is just one clock for both wires. So, what is the clock slaving? It is some king PLL driven phase-locking of one clock to another clock.  The key in here is to get reference and to trace the rate of change. Since the master clock is only one for both wires then the slave clock might look for the sampling marks in any of the wires ion case it reads samples from AES/EBU. In case the clock reference delivered to slave clock by own 75-ohm BNC word clock cable this cable can care ANY sampling frequency as long phase-wise it reflects the masterclock. I think this is why Pacific Microsonics  Model 2 does not output 176K clock and Model 1 does not output 88K clock. In fact I do not think that Model 2 even has 176K clock and Model 1 has 88K clock. They most likely have 44K and 48K (1X) clocks and multipliers. So, it is very possible that my concern about the half/clocking in dual-wire mode with Pacific was just my own self-inflicted worry.

Romy the Cat wrote:

Lynx has internal dabbler that activated as soon dual-wire inputs activated. So, when Pacific outputs in dual-wire configuration a half of the sampling speed then is done in accordance to the dual-wire specification.

Romy the Cat wrote:

It is possible that it does it, you might not know how to activate it or it defeated on your unit by some kind of hardware switch. Or perhaps it does it but you just do not know it.

Romy the Cat wrote:

Anyhow, I am sure Daniel would help you.

manisandher wrote:

The last I heard from him, he was looking into how to get the clock frequency doubled, maybe by an external device (I think).