[gnomen]

If I understand correctly you're using the dual-3-pin-XLR outputs at the back? And you like the sound better than the single-ended headphone output in the front?

In my case I use the RCA outputs as the XLRs are needed for the active speakers. On the Helios there is no front mounted headphone socket, so the Chiron adapter cable is needed, and sounds superb to my ears. I imagine others might use the XLRs instead if it suited their setup and worked better with their headphones, and there will be a Chiron cable suitable for that. For the Utopias the RCAs were fine ... amazingly good, in fact!

 

[Atriya]

I know many of you here prefer to have a separate headphone amplifier, and I admit I am not a headphonus supremus compared to most of you, but I cannot imagine how you could improve this sound by adding anything else.

As much as I wanted to believe that a separate headphone amp would be best (to avoid the digital volume control when using my 501's headphone output), I'm beginning to agree with you that adding anything to the signal chain necessarily takes away something.

I just got a Mass Kobo 433 for my Focal Utopia, and a tiny bit of resolution seems lost when directly compared to the headphone output on my 501-Mk2 (would never have noticed if I had not compared directly).

It's like a very slight reverb-effect added to the sound, which takes away a bit of the crispness from it, and adds a bit of haze.

I'm not even sure this is possible to avoid: I had noticed the same thing back when I had a Burson Soloist. I am using high-end XLR interconnects, so that's not the issue.

 

[warrenpchi]

I don't think there's inherently anything good or bad about adding an amp to the chain. Additional components can (and IMO should) change the sound - so as to be valid sound shaping devices.

Remember, while sound may be science, music is art. Choose what you like, and enjoy.

 

[chesebert]

As much as I wanted to believe that a separate headphone amp would be best (to avoid the digital volume control when using my 501's headphone output), I'm beginning to agree with you that adding anything to the signal chain necessarily takes away something.

I just got a Mass Kobo 433 for my Focal Utopia, and a tiny bit of resolution seems lost when directly compared to the headphone output on my 501-Mk2 (would never have noticed if I had not compared directly).

It's like a very slight reverb-effect added to the sound, which takes away a bit of the crispness from it, and adds a bit of haze.

I'm not even sure this is possible to avoid: I had noticed the same thing back when I had a Burson Soloist. I am using high-end XLR interconnects, so that's not the issue.

I think that’s just the sound of Mass Kobo. I wasn’t wowed when I heard 465 with Utopia.

 

[Atriya]

I don't think there's inherently anything good or bad about adding an amp to the chain. Additional components can (and IMO should) change the sound - so as to be valid sound shaping devices.

Remember, while sound may be science, music is art. Choose what you like, and enjoy.

I can agree that additional components may be used to shape/change the sound, and that the results will be subjective. However the loss of resolution doesn't seem to be a subjective matter, as I don't think anyone would actually prefer a lower resolution sound. At best it may be an acceptable compromise, to gain some other characteristic the component provides.

The point of my post was to ponder whether such a loss in resolution, no matter how small, must in fact necessarily occur when any component (such as a headphone amp) is added. In the case of my Mass Kobo 433, it does not seem small enough to be unnoticeable. Ditto with the Burson Soloist I had before. Ditto with various lower-end SS amps I've tried. Ditto with my LTA UL+ tube amp and other lower-end tube amps I've tried. Nothing seems to quite match the resolution coming directly out of the 501's headphone output.

 

[warrenpchi]

I can agree that additional components may be used to shape/change the sound, and that the results will be subjective. However the loss of resolution doesn't seem to be a subjective matter, as I don't think anyone would actually prefer a lower resolution sound. At best it may be an acceptable compromise, to gain some other characteristic the component provides.

Yes, exactly. Some might have a tonal preference that they can't live without. I consider myself a detailhead through and through, but as I've learned throughout my journey in this hobby, we come in all sound shapes and sizes.

The point of my post was to ponder whether such a loss in resolution, no matter how small, must in fact necessarily occur when any component (such as a headphone amp) is added.

I think that's the current reality of amplification. Every audiophile I've ever met (myself included) likes to believe that an ideal amp exists out there somewhere, and that we can somehow truly have "wire with gain" someday. But thus far that has proven elusive.

In the case of my Mass Kobo 433, it does not seem small enough to be unnoticeable. Ditto with the Burson Soloist I had before. Ditto with various lower-end SS amps I've tried. Ditto with my LTA UL+ tube amp and other lower-end tube amps I've tried. Nothing seems to quite match the resolution coming directly out of the 501's headphone output.

And I'd be willing to bet that's also the case with the 501's built-in amplification stage as well. It wouldn't surprise me if Daniel Weiss found some characteristics in the analog output that he's now working on improving?

 

[Mister Crash]

I did another experiment yesterday in my main system. I hooked up my 501-4ch along with my XLR switch so I could go back and forth between it and my MBL 1611F DAC that has served me for the past 15 years or so. I tried to volume match the two, which required setting the 501 output to -6.0 dB, then linked the Weiss and the Signature Rendu SE Roon endpoints and started playing music. For CD quality music, the two were very hard to distinguish. I tried some 88.2 and 96 kHz tracks as well, which performed very similarly between the two DACs.

But lately, I've been getting more into the DSD music format. I've bought a few dozen SACDs, ripped them, and added them to my Roon library. The MBL doesn't do DSD natively: it gets converted to PCM at 88.2 kHz by Roon, while the Weiss does process DSD natively. I had to turn down the Weiss volume even more to get them on the same level for DSD files (around -10.0 dB), but I did that and started listening.

The Weiss was definitely clearer and cleaner on DSD files. The MBL came off as softer and a little more muffled than the 501. One track I've been very fond of recently is "The Moon is a Harsh Mistress" from Radka Toneff and Steve Dobrogosz's album Fairytales. The Weiss showed off Toneff's voice and the acoustics of the concert hall incredibly well. The MBL was more subdued: it still sounded good, but it felt a little blurry.

Looks like I'll have to rethink my setups again...

 

[gnomen]

And I'd be willing to bet that's also the case with the 501's built-in amplification stage as well. It wouldn't surprise me if Daniel Weiss found some characteristics in the analog output that he's now working on improving?

Yes, maybe that is a contributor to the improvements with the Helios. As Daniel says (from memory) “the 501 is already very good, the Helios is a little better in some areas”

 

[Atriya]

the Weiss does process DSD natively.

Are you sure of this? My 501-mk2 converts DSD to PCM, and from the Stereophile review of the Helios, I see they say exactly the same about the Helios.

 

[Mister Crash]

Well, I can set Roon to output it as DSD, and when I do, the Weiss shows it as DSD64. If I pause the playback, it shows up as 176.4 hHz. I'm not clear on the technical aspects of DSD playback, so you could be right. With the MBL, Roon won't let it go above 96 kHz and doesn't offer DSD as an option in the setup.

 

[chesebert]

To my knowledge, there are only 4 dac manufacturers that have the tech to decode DSD in its native format: Playback Designs, Emm Labs, APL and PS Audio. Of those, only the first 3 have actually been involved in the development of DSD in one way or another. PS Audio kind of just approached the decoding from a software engineer perspective. Gran.Cen is doing something with DSD but no idea what they are doing given the bench results look bad.

 

[Atriya]

To my knowledge, there are only 4 dac manufacturers that have the tech to decode DSD in its native format: Playback Designs, Emm Labs, APL and PS Audio. Of those, only the first 3 have actually been involved in the development of DSD in one way or another. PS Audio kind of just approached the decoding from a software engineer perspective. Gran.Cen is doing something with DSD but no idea what they are doing given the bench results look bad.

AFAIK, there are many R2R DACs that convert DSD natively, such as all the Holo Audio DACs. They have a separate "1-bit" DAC for DSD which is not used for PCM.

 

[Atriya]

Well, I can set Roon to output it as DSD, and when I do, the Weiss shows it as DSD64. If I pause the playback, it shows up as 176.4 hHz. I'm not clear on the technical aspects of DSD playback, so you could be right. With the MBL, Roon won't let it go above 96 kHz and doesn't offer DSD as an option in the setup.

If you look at your Roon signal path, you will probably see that the Weiss is converting DSD to 176.4 kHz PCM internally. Of course this is different from your MBL which (it seems) doesn't accept DSD at all. With the MBL, you are relying on Roon to convert DSD->PCM for you. It is perhaps not surprising that the Weiss does that conversion better.

 

[chesebert]

AFAIK, there are many R2R DACs that convert DSD natively, such as all the Holo Audio DACs. They have a separate "1-bit" DAC for DSD which is not used for PCM.

That’s not how they work. That’s just how they market to layperson.

Edit: To add a bit of color, you simply cannot pass 1bit PDM stream to a multi bit dac without doing some math. Jeff Zhu of Holo talked about how Holo does it in a post (not here) and he said it’s similar to how Chord does the DSD decoding. Everyone has their own method but it’s never native unlike the native DSD dacs.

 

[Atriya]

So, in his review of the DAC204, @GoldenSound says:

"The DAC204 does not have any additional internal headroom and therefore will distort/clip in the presence of intersample overs. Recommended that you set your player volume to -3dB when using this DAC."

I hope the same is not also true of the DAC501/2? I have been using 0dB digital attenuation, as Weiss recommends.

And in case it is true, I wonder if it would only apply when using the 0dB analog attenuation setting, or also when that setting is -10dB/-20dB/-30dB.