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Post by Boomzilla on Oct 31, 2018 8:11:50 GMT -5
WITHOUT any accessories to remove noise or jitter, which interface do you find to sound best?
I vote for HDMI (High-Definition Multimedia Interface) with coaxial digital SPDIF (Sony/Philips Digital Interconnect Format) coming in a close second.
I find USB to sound the worst.
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Post by mgbpuff on Oct 31, 2018 8:29:12 GMT -5
I2s
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KeithL
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Post by KeithL on Oct 31, 2018 8:50:54 GMT -5
I think you need to be much more specific... because the interfaces on DACs themselves differ a great deal. It's not at all as if "all USB inputs perform and sound the same" and "most S/PDIF inputs sound and perform the same". There is actually a lot of variation between different examples of both.
For example, virtually ALL modern DACS with USB inputs SHOULD have an asynchronous USB interface - which has "an accessory to remove jitter" built in (the data is clocked by the input). Assuming that's working properly, it should "wipe away" most jitter that is present at the input (but may or may not be especially resistant to noise, and will have some low "floor level" of jitter of its own).
Older DACs, and a very few boutique modern DACs, have the old-style interface, where the clock is regenerated using PLLs... and which is far inferior. Likewise, many modern DACs, like our DC-1, and the new DC-2, have an ASRC built in - which is also "an accessory to remove jitter" (with Sabre DACs a similar mechanism is built into the DAC chip itself). So, with all of those, you are NOT "comparing interfaces without any accessories to remove jitter". Rather you are comparing them including the jitter reduction mechanisms that are already present inside the particular DAC... (Some can be disabled, and you will notice a difference with them enabled or disabled, but some cannot be switched out.)
And, like everything else, there are better and worse examples of each different type of input. In fact, on some of their models, Audio G*D used to offer multiple different options for each type of input...
They offered both different USB input chip-sets and different options for S/PDIF receiver chips.
And Schiit Audio, as I recall, is on their fifth version of their USB interface for their upgradable DACs. So..... by asking it like that you're sort of asking: "Which tastes better: fruit juice or soda?" So, really, you should request answers including the particular model and brand of DAC.
I also find your results interesting.... WITHOUT ADDITIONAL INTERNAL JITTER REDUCTION MECHANISMS, and ALL ELSE BEING EQUAL..... (both unlikely conditions)..... - an asynchronous USB input should have the lowest jitter and be most immune to jitter from any upstream components - S/PDIF should have very low inherent jitter, but is somewhat sensitive to jitter reaching it from upstream
- HDMI connections are relatively bad in terms of jitter - and old-style NON-asynch USB should be one of the worst (the connection itself has a lot of inherent jitter; and the input mechanisms those DACs use - mostly PLLs - vary widely, but none are especially good at it). - ALL audio sent over an Ethernet connection MUST be extracted and re-clocked at the destination... so ti depends entirely on how well the receiving device does its job.
Ground noise is another issue entirely. Devices with actual galvanic isolation on some inputs are very tolerant of noise... but many devices without isolated inputs are also tolerant for other reasons. While USB-powered DACs tend to be especially sensitive to it (especially if you're connecting them to a separate system which has its own ground, rather than to headphones, which are inherently floated).
I should also point out that jitter affects different DAC architectures differently. For example.... - Sabre DACs have something more or less equivalent to an ASRC built-in - Many multi- bit DAcs are claimed to be less sensitive to jitter (for a given amount of jitter present at the chip they produce fewer and lower sidebands than an equivalent D-S model; this makes them "very forgiving" of certain signal flaws). - From a high level, as a data format, DSD is inherently far more sensitive to jitter than PCM (because it's easier to "look at the data and clock separately" with PCM).
To answer the question.... for myself personally.....
I find a well designed asynch USB input to sound flawless.
(There's no real way to perform a direct comparison... since you're always dealing with different upstream components... but I haven't found anything that I consider to sound better than asynch USB in general.)
And I find S/PDIF inputs to have the ability to be very good, and just as good as USB with a good source, but to be sensitive to what source you use (and that includes things like re-clockers connected between them and the source).
WITHOUT any accessories to remove noise or jitter, which interface do you find to sound best? I vote for HDMI (High-Definition Multimedia Interface) with coaxial digital SPDIF (Sony/Philips Digital Interconnect Format) coming in a close second. I find USB to sound the worst. |
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Post by mauriceminor on Oct 31, 2018 8:52:04 GMT -5
1st: AES/EBU 110 Ohm
2nd: SPDIF 75 Ohm
(Bryston BDP-1 to Emotiva XDA-2) |
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DYohn
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Post by DYohn on Oct 31, 2018 9:52:46 GMT -5
AES/EBU
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Post by Boomzilla on Oct 31, 2018 9:59:58 GMT -5
But most consumer gear lacks this, yes? |
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Post by Boomzilla on Oct 31, 2018 10:03:55 GMT -5
I think you need to be much more specific... And after reading your comments, Keith, I think that such specificity just won't be possible. As you point out, the number of variables is far greater than I suspected, which may well be why the Audioquest Jitterbug and the Schiit Eiter that I've tried didn't do too much for me - My DACs were good enough that I didn't much need what the conditioners were doing, and so I heard little to no difference. All three of the DACs I use (Emotiva Stealth DC-1, Mytek Liberty, and the built-in DAC of the Arcam AVR550) are asynchronous and well-buffered. |
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Post by Bonzo on Oct 31, 2018 10:34:15 GMT -5
WITHOUT any accessories to remove noise or jitter, which interface do you find to sound best? I vote for HDMI (High-Definition Multimedia Interface) with coaxial digital SPDIF (Sony/Philips Digital Interconnect Format) coming in a close second. I find USB to sound the worst. I dunno. I'm just totally pissed off that you didn't give us the nerdy full blown definition for Toslink. 😁 |
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Post by fbczar on Oct 31, 2018 11:00:13 GMT -5
I think you need to be much more specific... And after reading your comments, Keith, I think that such specificity just won't be possible. As you point out, the number of variables is far greater than I suspected, which may well be why the Audioquest Jitterbug and the Schiit Eiter that I've tried didn't do too much for me - My DACs were good enough that I didn't much need what the conditioners were doing, and so I heard little to no difference. All three of the DACs I use (Emotiva Stealth DC-1, Mytek Liberty, and the built-in DAC of the Arcam AVR550) are asynchronous and well-buffered. Boom, The XMC-1 has an asynchronous USB input and the microRendu connected to the XMC-1 via USB improves the sound. Removing electrical noise from the system is the key, not jitter reduction. This is directly from the manufacturer of the Eitr: Just connect your USB source to Eitr’s USB input, and connect Eitr’s coaxial SPDIF output to any DAC that accepts coaxial input. Now, you have complete isolation from source to DAC, together with a superb, low-jitter coaxial SPDIF interface for bit depths and sample rates up to 24/192. USB, Solved: Gen 5 Technology The Eitr features the same unique Gen 5 USB input technology as in our upgradable DACs. It’s simply the highest-performance USB input available today, with complete electrostatic and electromagnetic isolation (via transformers), self-power of all critical low-noise and reclocking sections, and separate, precision clock sources for both 44.1 and 48kHz multiples. (And if you don’t understand the technobabble, here’s the point: it works great and sounds great, too.) Linear, Low-Noise Power Supply—Built In You won't need any "linear supplies" or other "add-ons" to improve Eitr—like all of our stackable products, we've built in a linear supply with multiple stages of ultra-low-noise voltage regulators. From the included 1.5A, 6VAC wall-wart to the output, there are no switching supplies in Eitr. |
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Post by garbulky on Oct 31, 2018 11:25:53 GMT -5
You have to also consider the room/equipment. Something as esoteric as jitter is going to be hard to be heard if there are bass humps, room reflections etc - if it can be heard at all. So everyone should ask - is my setup good enough to even hear it if it's there? As for Audioscience review keep in mind that currently their BEST performing DAC tested is the Oppo 205 their measurements shows is nearly perfect in measured performance. It tested 20 spots higher than Benchmark DAC1. Now reflect on that and your actual experience with that DAC and ask me which finding is more accurate for your experience?  So here you'll see that Oppo 205 according to their measurements is number 1. The Benchmark Dac 1 is NUMBER 20 which is EIGHT spots below an LG smartphone. You'll also find the Schiit Ygdrassil near the bottom of the list a few spots below an HP LAPTOP onboard sound card. So what I'm saying is ....take that site with a grain of salt. |
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Post by novisnick on Oct 31, 2018 11:49:45 GMT -5
You have to also consider the room/equipment. Something as esoteric as jitter is going to be hard to be heard if there are bass humps, room reflections etc - if it can be heard at all. So everyone should ask - is my setup good enough to even hear it if it's there? As for Audioscience review keep in mind that currently their BEST performing DAC tested is the Oppo 205 their measurements shows is nearly perfect in measured performance. It tested 20 spots higher than Benchmark DAC1. Now reflect on that and your actual experience with that DAC and ask me which finding is more accurate for your experience? So here you'll see that Oppo 205 according to their measurements is number 1. The Benchmark Dac 1 is NUMBER 20 which is EIGHT spots below an LG smartphone. You'll also find the Schiit Ygdrassil near the bottom of the list a few spots below an HP LAPTOP onboard sound card. So what I'm saying is ....take that site with a grain of salt. My friend, what you’ve brought to everyone’s attention is that audio pleasure and enjoyment can NOT be scientifically measured. Thank You! Take that you ney sayers! Yuck,,,,Yuck,,,,Yuck,,,,! |
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Post by garbulky on Oct 31, 2018 12:19:46 GMT -5
You have to also consider the room/equipment. Something as esoteric as jitter is going to be hard to be heard if there are bass humps, room reflections etc - if it can be heard at all. So everyone should ask - is my setup good enough to even hear it if it's there? As for Audioscience review keep in mind that currently their BEST performing DAC tested is the Oppo 205 their measurements shows is nearly perfect in measured performance. It tested 20 spots higher than Benchmark DAC1. Now reflect on that and your actual experience with that DAC and ask me which finding is more accurate for your experience? So here you'll see that Oppo 205 according to their measurements is number 1. The Benchmark Dac 1 is NUMBER 20 which is EIGHT spots below an LG smartphone. You'll also find the Schiit Ygdrassil near the bottom of the list a few spots below an HP LAPTOP onboard sound card. So what I'm saying is ....take that site with a grain of salt. My friend, what you’ve brought to everyone’s attention is that audio pleasure and enjoyment can NOT be scientifically measured. Thank You! Take that you ney sayers! Yuck,,,,Yuck,,,,Yuck,,,,! Though audio pleasure may not be measured. I hope that we can get closer to showing how the qualities we perceive in music like position of instruments in a soundstage, the dynamics etc can be presented more objectively when evaluating gear. |
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DYohn
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Post by DYohn on Oct 31, 2018 12:24:25 GMT -5
But most consumer gear lacks this, yes? In most? No. In some if you look for it? Yes. A good USB implementation can be just as good, but it must be a good one. Standard USB tends to sound like ass. |
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DYohn
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Post by DYohn on Oct 31, 2018 12:26:01 GMT -5
You have to also consider the room/equipment. Something as esoteric as jitter is going to be hard to be heard if there are bass humps, room reflections etc - if it can be heard at all. So everyone should ask - is my setup good enough to even hear it if it's there? As for Audioscience review keep in mind that currently their BEST performing DAC tested is the Oppo 205 their measurements shows is nearly perfect in measured performance. It tested 20 spots higher than Benchmark DAC1. Now reflect on that and your actual experience with that DAC and ask me which finding is more accurate for your experience? So here you'll see that Oppo 205 according to their measurements is number 1. The Benchmark Dac 1 is NUMBER 20 which is EIGHT spots below an LG smartphone. You'll also find the Schiit Ygdrassil near the bottom of the list a few spots below an HP LAPTOP onboard sound card. So what I'm saying is ....take that site with a grain of salt. I don't know what that graph is supposed to show but I can normally smell bovine manure from a mile away... and I detect a whiff..  |
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Post by garbulky on Oct 31, 2018 12:39:54 GMT -5
You have to also consider the room/equipment. Something as esoteric as jitter is going to be hard to be heard if there are bass humps, room reflections etc - if it can be heard at all. So everyone should ask - is my setup good enough to even hear it if it's there? As for Audioscience review keep in mind that currently their BEST performing DAC tested is the Oppo 205 their measurements shows is nearly perfect in measured performance. It tested 20 spots higher than Benchmark DAC1. Now reflect on that and your actual experience with that DAC and ask me which finding is more accurate for your experience? So here you'll see that Oppo 205 according to their measurements is number 1. The Benchmark Dac 1 is NUMBER 20 which is EIGHT spots below an LG smartphone. You'll also find the Schiit Ygdrassil near the bottom of the list a few spots below an HP LAPTOP onboard sound card. So what I'm saying is ....take that site with a grain of salt. I don't know what that graph is supposed to show but I can normally smell bovine manure from a mile away... and I detect a whiff.. Supposed to be signal to noise and distortion ratio |
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DYohn
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Post by DYohn on Oct 31, 2018 13:01:28 GMT -5
I don't know what that graph is supposed to show but I can normally smell bovine manure from a mile away... and I detect a whiff.. Supposed to be signal to noise and distortion ratio Something they made up? Why not just list S/N and distortion? Actually, the "noise" part of S/N is by definition part of 'distortion" so all you really need is the THD+N spec. But again, this chart is absolute rubbish and tells me nothing. |
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Post by garbulky on Oct 31, 2018 13:22:15 GMT -5
Supposed to be signal to noise and distortion ratio Something they made up? Why not just list S/N and distortion? Actually, the "noise" part of S/N is by definition part of 'distortion" so all you really need is the THD+N spec. But again, this chart is absolute rubbish and tells me nothing. I've found a few issues where I feel they've clearly overstepped. In determining amp power they determine clipping as the moment there is even a tiny increase in THD. This means 0.001% THD is considered clipping rather than when it's actually clipping. The justification is that the amp is getting "saturated". Well I think that's nuts when 0.001% distortion is considered clipping and shows amps seriously underperforming. The other is in linearity. They self-define a dac as equivalent to so many bits as long as it's literally perfectly linear to +/- 0.1 db. So that means even if it's linear at 19 bits with a +/- 1 db difference it's not considered a 19 bit dac because it's failed the 0.1 db definition. So with this definition multibit dacs perform very poorly in these tests and get rated as being much lower. For instance the Schiit Ygdrassil was rated as being equivalent to 16 bits of resolution. These two ways of under-rating gear is imo dishonest and not keeping with usual practices. |
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Post by Casey Leedom on Oct 31, 2018 13:27:09 GMT -5
Yeah, I have to agree with KeithL on this: what we really want is a set of technical reviews for Input and Output Ports of various Technologies for various devices. And the data gathered would need to be per-Technology. For instance, for USB Output Ports (and the Driver Software being used) you might measure Electrical Noise and Jitter (see later), while for USB Input Ports (and the Driver Software being used), you might measure Immunity to Electrical Noise (Galvanic Isolation) and Immunity to Jitter (for example using using Isochronous Mode and reclocking the Audio Data). So if you had a really crappy source USB which put lots of electrical noise on the USB and the Isochronous Packets were transmitted with a fairly large random distribution of timing (but not so large as to completely meet the Data Delivery Deadlines for the Audio), then you'd really want a DAC with good Electrical Noise Immunity and was reclocking the Audio Data. On the other hand, if you had a really good USB Transmitter, you could get away with a DAC that had a crappy USB Input section. On this latter front, a good friend of mine has a Teac NT-503 using Asahi Kasei Microdevices AK4490EQ chips in Dual Monaural mode. He loves it but claims that he heard a huge improvement when going from a Raspberry Pi/ Ropieee Roon Bridge USB source to an sMS-200ultra Neo Roon Bridge USB Source. For the sake of argument, we'll accept my friend's claim that there's an improvement. In this case, everything has stayed the same except the USB Source. The same Digital Audio Data is being read off of disk, transmitted across Ethernet, eventually transmitted across the USB Cable and into the Teac NT-503. Only that little bit between the Ethernet and USB has changed. What I would gather from the above is that the Teac NT-503 has a crappy USB Input and the sMS-200ultra Neo has a good USB Output. But that $1,200 sMS-200ultra Neo wouldn't have been needed if the Teac Engineers had done their jobs properly. Casey |
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KeithL
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Post by KeithL on Oct 31, 2018 14:10:40 GMT -5
What the Eitr is doing is REPLACING the USB input on your particular DAC with its own USB input circuitry - and adding its own galvanic isolation. And you should also note that, among other things, some DACs actually already have galvanic isolation - on either their USB input, their S/PDIF input, or both.
Obviously, the USB input circuitry on different DACs and other equipment varies considerably... and not all asynchronous USB inputs are necessarily good.
And, if you had a vintage XDA-1, whose USB input is limited to 48k, but whose other inputs go up to 24/192k, adding an Eitr would allow it to accept up to 192k via USB - because you are upgrading the USB input. However, the Eitr is NOT some revolutionary new device.... it is a "USB-to-S/PDIF converter".... which have actually been around for quite some time. (The Eitr does seem to offer good performance at a reasonable price). I should also remind everyone that, if galvanic isolation was the only important issue, ALL Toslink inputs have absolutely perfect galvanic isolation.
Electrical noise affects every device differently... but it is usually audible as noise when it's causing a problem (although not always).
And after reading your comments, Keith, I think that such specificity just won't be possible. As you point out, the number of variables is far greater than I suspected, which may well be why the Audioquest Jitterbug and the Schiit Eiter that I've tried didn't do too much for me - My DACs were good enough that I didn't much need what the conditioners were doing, and so I heard little to no difference. All three of the DACs I use (Emotiva Stealth DC-1, Mytek Liberty, and the built-in DAC of the Arcam AVR550) are asynchronous and well-buffered. Boom, The XMC-1 has an asynchronous USB input and the microRendu connected to the XMC-1 via USB improves the sound. Removing electrical noise from the system is the key, not jitter reduction. This is directly from the manufacturer of the Eitr: Just connect your USB source to Eitr’s USB input, and connect Eitr’s coaxial SPDIF output to any DAC that accepts coaxial input. Now, you have complete isolation from source to DAC, together with a superb, low-jitter coaxial SPDIF interface for bit depths and sample rates up to 24/192. USB, Solved: Gen 5 Technology The Eitr features the same unique Gen 5 USB input technology as in our upgradable DACs. It’s simply the highest-performance USB input available today, with complete electrostatic and electromagnetic isolation (via transformers), self-power of all critical low-noise and reclocking sections, and separate, precision clock sources for both 44.1 and 48kHz multiples. (And if you don’t understand the technobabble, here’s the point: it works great and sounds great, too.) Linear, Low-Noise Power Supply—Built In You won't need any "linear supplies" or other "add-ons" to improve Eitr—like all of our stackable products, we've built in a linear supply with multiple stages of ultra-low-noise voltage regulators. From the included 1.5A, 6VAC wall-wart to the output, there are no switching supplies in Eitr. |
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KeithL
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Post by KeithL on Oct 31, 2018 14:34:19 GMT -5
I would add one thing to what you said....
The USB data medium itself is packet based... so it is inherently high in jitter... therefore there is no such thing as a true low jitter USB source... it's simply not possible. With old style USB inputs (isochronous), the DAC regenerated the data clock by "locking onto" the cadence of the packets using one or more PLLs, and so its performance could be improved by more consistent packet timing. With modern asynchronous USB receivers, the data is clocked by the receiver, so the cadence of the packets really doesn't matter (unless it is so far off that it interferes with accurate data transfer - which rarely if ever happens). (There may be some USB inputs out there that are actually sensitive to packet cadence... but I would classify them as "bad".) (Likewise, there can be computer sources that have such bad packet latency that they cause actual data loss... ) A device like the Eitr removes jitter at the final stage of the signal path, as the data is being passed to the DAC, and so should obviate any possible benefits of any device along the signal chain before it. Likewise, Ethernet is packet based, and essentially time non-deterministic. (As long as the packets arrive, more or less promptly, and more or less in order, Ethernet has done its job.) It is up to the device reassembling the packets and extracting the audio stream to do so properly and to synchronize them to a high-quality clock. (However, when going from Ethernet, which is packet based, to USB, which is also packet based, a lot of precision shouldn't actually matter.)
The only important point is the clock which is associated with the data at the point where it is presented to the DAC chip itself (and, of course, the data itself).
Noise immunity is a whole separate question... And some devices are simply more immune to noise than others... And, if your device is sensitive to it, then a quieter source, or galvanic isolation, may help the situation.
However, to be completely candid, I an quite convinced that a significant percentage of the claims made for many of these gadgets include a significant percentage of hyperbole. While it's certainly true that SOME of them may help solve CERTAIN problems in CERTAIN systems, I doubt that most systems would benefit from most of them.
I should also add a bit of perspective.... It only costs you $50 to find out what a Raspberry Pi sounds like as a music server....
Yeah, I have to agree with KeithL on this: what we really want is a set of technical reviews for Input and Output Ports of various Technologies for various devices. And the data gathered would need to be per-Technology. For instance, for USB Output Ports (and the Driver Software being used) you might measure Electrical Noise and Jitter (see later), while for USB Input Ports (and the Driver Software being used), you might measure Immunity to Electrical Noise (Galvanic Isolation) and Immunity to Jitter (for example using using Isochronous Mode and reclocking the Audio Data). So if you had a really crappy source USB which put lots of electrical noise on the USB and the Isochronous Packets were transmitted with a fairly large random distribution of timing (but not so large as to completely meet the Data Delivery Deadlines for the Audio), then you'd really want a DAC with good Electrical Noise Immunity and was reclocking the Audio Data. On the other hand, if you had a really good USB Transmitter, you could get away with a DAC that had a crappy USB Input section. On this latter front, a good friend of mine has a Teac NT-503 using Asahi Kasei Microdevices AK4490EQ chips in Dual Monaural mode. He loves it but claims that he heard a huge improvement when going from a Raspberry Pi/ Ropieee Roon Bridge USB source to an sMS-200ultra Neo Roon Bridge USB Source. For the sake of argument, we'll accept my friend's claim that there's an improvement. In this case, everything has stayed the same except the USB Source. The same Digital Audio Data is being read off of disk, transmitted across Ethernet, eventually transmitted across the USB Cable and into the Teac NT-503. Only that little bit between the Ethernet and USB has changed. What I would gather from the above is that the Teac NT-503 has a crappy USB Input and the sMS-200ultra Neo has a good USB Output. But that $1,200 sMS-200ultra Neo wouldn't have been needed if the Teac Engineers had done their jobs properly. Casey |
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