"An unexpected surprise" or "Is this a fair way to compare DACs?"

DC

Active Member
Ramblings on an somewhat-unexpected Sunday off...

I'm kind of new to the whole computer-->DAC way of listening of music. I got a Tidal subscription last summer, though I have used it very little. And just prior to that I got Roon and it found the 100 or so CDs I ripped in to iTunes like 10 years ago, and interfaces with Tidal, and there's a phone app. So that's pretty cool. And I've got to work through a bunch of orphaned album tracks in Tidal that need to be manually re-combined, but I think I figured out how to do that. (And now that iTunes is apparently being phased out, I find myself more a visionary than luddite, haha.)

Anyway, the analog out from the Mac Mini to my preamp was "okay" - definitely not bad, but not comparable with my other sources, and enough to take notice, which is why I think I didn't really listen to it much - the sound was just "meh" and I found I'd rather just spin a CD or LP (or Hell, the radio, if I was feeling lazy). I just didn't go to the computer for music.

So I put out a request on the local audio club group and a few offers to loan a DAC for some listening quickly came forth. I ended up with a MicroMega MyDac (who thinks of these names?) courtesy of @Olson_jr for some weeks. (It's still here.) It was a clear improvement over the analog computer output - no surprise. It has USB as well as optical input, and I tried both, though I can't say whether I noticed that one interface was better than the other. (I thought I remembered some vehemence in the past that coaxial is usually preferred over optical if you've got the choice, and no clue how USB compares.)

Then on an impulse after seeing @MikeT.'s ad (elsewhere) for his iFi micro iDAC2 with some accessories, I bought it, confident that as a current "better" product and with MQA capability, it would be a nice step up. And I think it was. While the MyDac was an improvement over the analog out, the iFi is another improvement over that. Not shocking.

Another local friend said I could borrow his Musical Fidelity Tri-Vista 21 DAC, an upper-tier unit, but from about 15 years ago. It's got output tubes, no MQA, no USB, and a chipset a few generations older than these others (even the computer). But what the heck, why not? It's up here too, warmed up and humming along.

TL : DR - Here is my question: The Tri-Vista 21 DAC is connected to the Mac Mini via optical, the only way to interface the two. The iFi Micro iDAC2 is hooked up via USB, also the only way to interface those two. Both units are connected to the preamp via the same length/make/model RCA cables. Roon is configured to "group" the two "devices" and play to both "zones" at once, and they're level-matched to within ~0.2dB, so I can easily switch between the two. So the question is: Is there anything else I can do to level the playing field more? (And is optical vs. USB a limiting problem, or a non-issue?) Is this a reasonable way to compare them fairly?

Of course, the bigger question is whether or not this is even a fair comparison, which leads to the surprise part: I had fully anticipated that the new little iFi DAC would sound preferable to the big old Musical Fidelity DAC due to the 15+ years of advanced technology - I expected it would simply be "better" without question. But so far, the Tri-Vista seems to have the edge - a wider soundstage, a bit more crisp, and a little more excitement without being edgy or "tipped up" - it seems more musical. The iFi seems a bit more recessed and narrower, not as open and airy - it seems more clinical. Again, not a fair comparison, but I'm genuinely surprised at how marked the difference is. The obvious unfairness part is that the Musical Fidelity was ~$2500 and is over-engineered and over-built; the iFi is a better-than-entry-level device at ~$400 and intended to be versatile and portable.

One is here to stay, the other is on borrowed (literally) time, so it's just academic.

Eh?
 

MikeyFresh

Moderator
Staff member
Another local friend said I could borrow his Musical Fidelity Tri-Vista 21 DAC, an upper-tier unit, but from about 15 years ago. It's got output tubes, no MQA, no USB, and a chipset a few generations older than these others (even the computer).
Thats a really nice legacy DAC, the absolute real deal despite lacking some of the most modern amenities.

But so far, the Tri-Vista seems to have the edge - a wider soundstage, a bit more crisp, and a little more excitement without being edgy or "tipped up" - it seems more musical.

I'm not surprised you prefer it, a big power supply and vacuum tube output stage will do that. Note that DAC performs hardware upsampling of 16/44.1 to either 24/96 or 24/192kHz by default. That upsampling is switchable from the rear panel, which may seem inconvenient, but they didn't intend for folks to go back and forth with it, rather, they expected you to pick the one you like better and stay with it.

I have a legacy DAC that does the same, the PS Audio DL III has a switch just like the Tri-Vista 21 does, though it is located on the front panel rather than the rear panel. PS Audio always maintained they thought the unit sounded better at 96 kHz than it did at 192 kHz, and I concurred. In a perfect world the switch would also have a defeat position, so that you could elect no upsampling, but this vintage of DAC often didn't include that feature, by design everything went through the SRC.

So the question is: Is there anything else I can do to level the playing field more? (And is optical vs. USB a limiting problem, or a non-issue?) Is this a reasonable way to compare them fairly?

You could try elevating the USB power quality driving the iDAC2, which should provide a major positive effect, as computer power/GND is often pretty damn noisy. Adds cost however, as does a good quality USB cable. I use an iDAC2 in my bedroom system along with iFi's dual head Gemini USB cable, not because I think that cable is super special, but because it separates the power and data. The power and GND are cleaned by the iFi iUSB 3.0, and output over separate jacks.

Optical vs. USB is an interesting question, while Toslink is much maligned, it can actually sound great if for no other reason due to the inherent galvanic isolation it provides.

But quality matters there too, cheap POF-based Toslink cables are usually mediocre at best, something like the Wireworld Super Nova 7 glass cable should clearly outperform the cheap stuff. My preference there is for the Lifatec Silflex glass cable, a medical grade Toslink cable sold direct (no 50% dealer margin), so it's about as cheap as you will find this kind of thing but still very high quality. Glass cables are somewhat fragile and prone to micro fractures if subjected to any rough handling, you are wise to just carefully install and leave it alone, no sharp bends, no snaking it through any tight spaces, etc...

I mention the above not because I wish to invite a forum flaming to the effect of "how dare you suggest such cost/complexity, snake oil, shit... all those untidy wires!". Rather, just some food for thought in answering your questions, especially if your local scene would allow you to borrow any of that stuff to try rather than buy.

Or, if you just want to run straight out of the computer, I'd prefer high quality Toslink for that as the galvanic isolation prevents the noisy computer power/GND from infecting the Hi-Fi system. I used Toslink first out of a Mac mini, and then an Apple Airport Express into that PS Audio DL III for many years, upsampling Redbook to 24/96. If that's all I ever had, no problem, because it sounded great.

My 2 cents, the Tri-Vista 21 is an oldie but goodie, too bad it has to go back to it's owner.
 

Olson_jr

Active Member
Don, if I knew you were doing this I could have lent you a Singxer SU-1 (the Kitsune tuned edition) that has two S/PDIF outputs. That would allow you to run the two DACs from one USB/SPDIF interface.

Hell, if I knew you were this interested in digital I can lend you the Holo Audio Spring "Kitsune Tuned Edition" Level 3 DAC and/or the PS Audio DSD DAC.

BTW, a little bird told me that we both had the same opinion of the 32A's.
 

DC

Active Member
Thats a really nice legacy DAC, the absolute real deal despite lacking some of the most modern amenities.



I'm not surprised you prefer it, a big power supply and vacuum tube output stage will do that. Note that DAC performs hardware upsampling of 16/44.1 to either 24/96 or 24/192kHz by default. That upsampling is switchable from the rear panel, which may seem inconvenient, but they didn't intend for folks to go back and forth with it, rather, they expected you to pick the one you like better and stay with it.

I have a legacy DAC that does the same, the PS Audio DL III has a switch just like the Tri-Vista 21 does, though it is located on the front panel rather than the rear panel. PS Audio always maintained they thought the unit sounded better at 96 kHz than 192 kHz, and I concurred. In a perfect world the switch would also have a defeat position, so that you could elect no upsampling, but this vintage of DAC often didn't include that feature, everything went through the SRC.



You could try elevating the USB power quality driving the iDAC2, which should provide a major positive effect, as computer power/GND is often pretty damn noisy. Adds cost however, as does a good quality USB cable. I use an iDAC2 in my bedroom system along with iFi's dual head Gemini USB cable, not because I think that cable is super special, but because it separates the power and data. The power and GND are cleaned by the iFi iUSB 3.0, and output over separate jacks.

Optical vs. USB is an interesting question, while Toslink is much maligned, it can actually sound great if for no other reason due to the inherent galvanic isolation it provides.

But quality matters there too, cheap POF-based Toslink cables are usually mediocre at best, something like the Wireworld Super Nova 7 glass cable should clearly outperform the cheap stuff. My preference there is for the Lifatec Silflex glass cable, a medical grade Toslink cable sold direct (no 50% dealer margin), so it's about as cheap as you will find this kind of thing but still very high quality. Glass cables are somewhat fragile and prone to micro fractures if subjected to any rough handling, you are wise to just carefully install and leave it alone, no sharp bends, no snaking it through any tight spaces, etc...

I mention the above not because I wish to invite a forum flaming to the effect of "how dare you suggest such cost/complexity, snake oil, shit... all those untidy wires!". Rather, just some food for thought in answering your questions, especially if your local scene would allow you to borrow any of that stuff to try rather than buy.

Or, if you just want to run straight out of the computer, I'd prefer high quality Toslink for that as that galvanic isolation prevents the noisy computer power/GND from infecting the Hi-Fi system. I used Toslink first out of a Mac mini, and then an Apple Airport Express into that PS Audio DL III for many years, upsampling Redbook to 24/96. If that's all I ever had, no problem, because it sounded great.

My 2 cents, the Tri-Vista 21 is an oldie but goodie, too bad it has to go back to it's owner.

Thanks, Mike. I appreciate your insights.

I should add a few details:
- The Tri-Vista has been serviced in the recent past, and is operating in top form, though I am only using an inexpensive AudioQuest “Evergreen” optical cable to the ‘Mini. It’s been around here for a while, but mostly unused, and haven’t tied any knots in it yet.

- I am using the iDefender ground loop isolator and iPower external power supply on the iFi, sort of a budget version of your setup with the Gemini/iUSB3.0? So the USB power here should be a little quieter, better than baseline, anyway.

I had not considered the advantage of galvanic isolation inherent to the optical connection - didn’t know that was a thing - but it makes perfect sense. Now I know, and can see (ha) the benefit.

I guess I also had not considered the advantages of a superlative “legacy” digital device. I’ve always kind of assumed that the useful life of any digital product is short and prone to early obsolescence, and to spend big money on something would be shortsighted. And which is why I was originally surprised at how good the TriVista sounded side by side with something so much newer, though your explanation as to why makes sense.

So I guess I’ll re-evaluate my pre-conceived notions and try to re-educate my ignorance. And in the meantime (week or so to return the borrowed DAC), I’ll just listen and enjoy.
 

DC

Active Member
Don, if I knew you were doing this I could have lent you a Singxer SU-1 (the Kitsune tuned edition) that has two S/PDIF outputs. That would allow you to run the two DACs from one USB/SPDIF interface.

Hell, if I knew you were this interested in digital I can lend you the Holo Audio Spring "Kitsune Tuned Edition" Level 3 DAC and/or the PS Audio DSD DAC.

BTW, a little bird told me that we both had the same opinion of the 32A's.

I wasn’t quite “this interested” in digital, it just sort of happened. And let me “The Google” the rest of your message to see if I can figure out what the heck you’re saying.

And I didn’t prefer the 32As. I guess I just don’t like horns.
 

MikeyFresh

Moderator
Staff member
I am only using an inexpensive AudioQuest “Evergreen” optical cable to the ‘Mini.

I have an Evergreen kicking around here somewhere, I did feel the glass cable smoked it, but of course other's mileage may vary.

- I am using the iDefender ground loop isolator and iPower external power supply on the iFi, sort of a budget version of your setup with the Gemini/iUSB3.0? So the USB power here should be a little quieter, better than baseline, anyway.

Yes, that's going to be not too dissimilar to what I'm using, and I think the most important part is severing the common GND with the computer. The re-clocking and "cleaning" of the data line is very likely of lesser importance, as the iDAC2 does already have a built-in "Zero Jitter" and "Active Noise Cancellation" circuit.
So I guess I’ll re-evaluate my pre-conceived notions and try to re-educate my ignorance. And in the meantime (week or so to return the borrowed DAC), I’ll just listen and enjoy.

Always a good thing, I too used to just believe Toslink sucked, until I revisited it after about 10 years. Turns out Toslink can be quite good, especially with a glass cable, if the source and DAC have a properly implemented scheme for optical.

In the meantime listen and enjoy!
 

DC

Active Member
Don, if I knew you were doing this I could have lent you a Singxer SU-1 (the Kitsune tuned edition) that has two S/PDIF outputs. That would allow you to run the two DACs from one USB/SPDIF interface.

I don’t think that would work, the iFi only has USB in.

Hell, if I knew you were this interested in digital I can lend you the Holo Audio Spring "Kitsune Tuned Edition" Level 3 DAC and/or the PS Audio DSD DAC.

Thanks, but not yet. Let’s wait ‘till I have a clue about what the heck I’m doing, first.
 

DC

Active Member
A little more listening and enjoying, and now the Tri-Vista is back home with its owner.

I hate to say it - it's so cliché - but with further listening, the Tri-Vista actually did a good job of sounding a little more analog than digital, and in a good way. The iFi does a little better job with bass, at least here in my system and room.

All done now, pics for posterity:

8783DE70-B439-4DAD-B441-2B5227B68D5E.jpeg

C5D5B880-B307-4E28-A7FA-2C4817F4099A.jpeg
 

Thermionics

Post Whore In Training
Eeeek!

In my experience, placing a DAC on top of a computer is like placing a turntable on top of a subwoofer. Add to this that analog circuits in the micro iDAC2 are being powered from the computer's noisy USB bus. This placement and configuration significantly handicaps the performance of the little iFi DAC.
Can you explain the turntable on subwoofer analogy? There are no moving parts in a USB DAC that can be affected by the computers mechanicals. If you are referring to EMF / RF, that's another issue entirely, but even then, the USB DAC should be sufficiently shielded by the aluminum clamshell.
 

dsnyder0cnn

Junior Member
Can you explain the turntable on subwoofer analogy? There are no moving parts in a USB DAC that can be affected by the computers mechanicals. If you are referring to EMF / RF, that's another issue entirely, but even then, the USB DAC should be sufficiently shielded by the aluminum clamshell.

It's RFI and ground plane noise. It would be lovely if the aluminum chassis was adequate, but that is almost never the case. Regardless, separating the two is cheap. I can't think of any reason to not do so.

In my system, the computer running the music server software is two floors below the listening room. This level of separation is the least expensive way to eliminate effects of EMF/RFI emissions from the computer on the listening environment. Aurender takes another approach by going to heroic efforts in hardware. That's also effective, but definitely not cheap (up to $18k).
 

Thermionics

Post Whore In Training
It's RFI and ground plane noise. It would be lovely if the aluminum chassis was adequate, but that is almost never the case. Regardless, separating the two is cheap. I can't think of any reason to not do so.
Thanks for clarifying. Luckily EMF / RF are subject to inverse square law if I remember correctly, so a modicum of distance should reap huge benefits.
 

MikeyFresh

Moderator
Staff member
Thanks for clarifying. Luckily EMF / RF are subject to inverse square law if I remember correctly, so a modicum of distance should reap huge benefits.

Of course the same would be true of any/all cables connected too. Dressing them so that they are even just a few inches away from each other as opposed to touching or right next to each other usually yields a sonic benefit.
 

Olson_jr

Active Member
Rule 3: Keep an eye on the Signal Path
Features like Volume Normalization, Crossfade, DSP volume controls, and DSP Engine all affect what you're hearing. If you have those things turned on, and you're not happy with what's coming out, it's worth experimenting with turning them off or changing their settings.

Note that Roon's DSP volume control is a pass-through at 100% volume--so it should have no influence unless it's being used.

You can always check Signal Path to see what is going on.

When I first started using Roon I was impressed with all the features within DSP and was playing with them frequently. I won't mention how many times I had futzed with something and then forgot to change it back before my next listen. Thank goodness for that Signal path light.
 

Olson_jr

Active Member
Finally, repeat after me: "I will never connect a DAC to my Music Server!"

I am running Roon on a Small Green Computer using SonicTransporter to output over ethernet to either a PS Audio Bridge II & DSD DAC or to a Sonore microRendu feeding a Singxer SU-1 (the Kitsune tuned edition) & I2S run to a Holo Audio Spring "Kitsune Tuned Edition" Level 3 DAC.


Doesn't this mean that I have violated your above rule? My DACs are connected to my Music Server.

Kidding aside, I do feel going away from USB to the ethernet was a very big leap forward in my digital listening.

I will have to watch your video later.
 

DC

Active Member
Wow, given the level of EMI/RFI I'm likely experiencing, it's a wonder I can hear anything at all through the DACs. Perhaps I'll just go back to spinning LPs.
 

DC

Active Member
Wow, given the level of EMI/RFI I'm likely experiencing, it's a wonder I can hear anything at all through the DACs. Perhaps I'll just go back to spinning LPs.

Sorry, that sounded ruder than it was intended. Let me rephrase it:

Thanks for the insights, it's much appreciated. I'm not a digital die-hard, but am always interested in making a better effort if I can, which was probably the impetus behind this thread. While I'm not likely to create a remote server and/or buy additional communication devices, I can easliy move the iFi DAC (when I return to using it) away from the computer to a better location. I have about 25 years experience with RF and am familiar with the inverse-square law as it pertains to EMI/RFI. Though I had not considered the potential problem(s) as explained above, I can see how distancing the DAC from the computer and redressing the cables a bit could be helpful. (The iFi DAC is already using a separate USB power supply with ground isolator from the computer buss.)

Once the PS Audio goes back home, I'll futz with this a bit more. I'm not bothering at all to compare these two DACs as I did the Tri-Vista above, as what would be the point?
 
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