Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 535

The idea of converting a PCM stream in USB to a SPDIF signal has always seemed to me to be a good way to degrade the signal. I'm listening to my Zero through a Xitel MD-Port DG2 (USB->optical SPDIF converter). After reading these last few posts I thought I'd see if I could find a way to give the Zero PCM data straight from my PC. I figured out how to take the digital out from my X-Fi card and feed it to the Zero and...

Wow.

Did I mention ... WOW!

If there high freq harshness was a 8 on a 10 scale, now it's 2. Dramatic reduction.

I'm either going to buy a second sound card and dedicate it to feeding the Zero or look for alternative USB converters. Having said all that, are there any thoughts on the HD 2902 as compared to the Xitel? Maybe it's Coax vs. Optical? Maybe it's just removing the USB conversion step or maybe the Xitel just sucks?

Thoughts?

Xitel DG2 has serious jitter problem, see here. PCM2902 is way better.

Taken from Currawong's "Introduction to the Zero DAC and Headphone amplifier." Can anyone else comment on this? How much better will my setup sound with a dedicated amp? I already have the Burr Brown OPA627s the two LT1364's. I am powering Beter DT770's (the 250 consumer version). Also, how much better would an HDAM sound than the OPAMP? I am getting the impression that I am not that sensative to slight differences in SQ, therefore I don't know if it would be worth it to buy any more upgrades.

Perfect timing for me to answer your question. I have HDAM and LT1364's talking to Senn HD650's. The Zero Dac/Headamp was a VAST improvement over the line out of my Pretty Good SC. Then I bought a Little DOT MKV, and it is a Vast improvement over the Zero head amp. More presence, more 3 dimensional, base tighter and more prominent, voice is so much smoother and 3-D like. At least that is how I am hearing it with HD650's. A less demanding HP may be different, but I don't think so. I was very happy with the Zero. I've been burning in the LD for a week or so, and listening off and on. Tonight, I went back and forth a few times on the opening minutes of Godsmack's Voodoo, and the difference was staggering. It always is bigger to drop down than to go up in performance. You always notice the decrease right away, the increase in performance can sometimes take a while to fully realize.

Admittedly, the 650's are notorious for lapping up performance from ever increasing quality of amplification. I'll have some Denon D5000's tomorrow, and some Beyer DT770-80's this week to go over also.

So, if I had never heard the LD MKV I would have been happy as a Clam. I'm getting ready to do the DV 337SE, which will be interesting also.

Digital Output

For what it is worth, in relation to the discussion of the different methods of getting a digital signal into your Zero, I just tested the difference between the digital output of my crappy onboard sound card (Gigabyte motherboard) and the crappy usb optical output module that came with my Zero. On both the SPDIF and the optical signal from my onboard soundcard, I noticed popping and almost a background of static (faint but definitely noticeable) build up. Definitely noticeable distortion that even my ears could hear. With the usb to optical module I did not hear any distortion, popping, or static. I will let the other guys explain why this is so.

Why does everyone use the usb SPDIF versus a usb to optical module? Is the SPDIF better in some way?

This is along the same lines as the question previously being discussed, but wouldn't any distortion or degradation in the digital signal (between different methods of sending and quality of devices used for the conversion from PCM to the digital signal that the zero reads) be readily identifiable as it would manifest itself as pops, hisses, or static? This is opposed to the slippery nature of analog distortions where differences in quality are much harder to identify without ABX type testing. Am I correct with this?

hey phewl did you change the volume knob on the zero? how's the stock knob?

isn't optical spdif as well? i thought coax and optical were both spdif.

how did you manage to get usb feeding PCM data straight to your zero bypassing the spdif??

Hmm... I probably didn't say that right. I connected the digital out on my sound card to the coax jack on the Zero.

Nice Pictures, Mr. Wong.

Sorry, I meant both coax and optical. You are right, SPDIF includes both.

I just got my Zero and my Xbox 360's optical out to it works just fine, but I'm not getting any audio using coax from my X-FI Xtreme Music. Do I HAVE to have that stupid digital I/O port they sell or can't I just run a 3.5mm to RCA SPDIF cord to my zero?

IMO, the audio-gd HDAM module is the single upgrade needed for the Zero to sound in the next league up. Other mods are worthwhile, and have been discussed in-depth on this site, but the HDAM is a superb starting point for any upgrades.

The different flavours offer different sound characteristics. I've used the Earth and Sun modules - Earth is very neutral, Sun is more punchy and dynamic but more fatiguing for long-term use. No experience of the Moon, so I couldn't comment on that at all.

Standard knob. It serves its purpose adequately. There are better knobs out there, but I only want to part with cash for better sound.

Besides, I rarely use the headphone amp these days. My Stax cans came with their own dedicated amplifier.

~Phewl.

Sorry to disturb your op-swapping

Brief question (Long thread is long):
Does the volume control apply to the line-out stage, meaning it would work as a preamp? I have a set of Adam A5 activespeakers, and would love to know if this amp is up for the job of functioning as an adequate headphone amp as well as setting the volume for my speakers..

Thanks in advance!

-K

No problem there, mentioned on Page 1