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

[MadMan007]

Ok, here's the follow up regarding my problem I've been meaning to post but I've been busy, I bought multiple units with the intent of reselling. Two of them were fine, to recap the problem with the other two, after playing for a few minutes one channel started to degrade quickly and became distorted then would only play at a much lower volume as well. This was through the preamp as well as the HA so the problem seemed to be in the DAC section. wsz (the seller) suggested I try swapping the OPA627 from the good units in to the bad ones and they worked fine, I test ran them for over 12 hours trying all inputs and outputs and had no further problem. So it turns out I had bad OPA627 Opamp modules not really sure how that happens but whatever. Anyway I was sent replacements and all is good now.

So, if you've got a problem with one channel in particular being distorted or playing really quietly through both the pre- outs and the HA it's likely the DAC opamps are bad.

wsz on eBay has awesome communication and great customer service. He was prompt and as helpful as he could be in troubleshooting and solving the problem. He took care of the problem with no question as well, I would highly recommend him to anyone who has concerns about not getting a perfect unit.

LT1364 - I ordered samples from Linear Tech and popped them in. I'd listened to the stock HA section and it was Ok, with the LT1364s it got..different, in a better way I suppose. I didn't do any back and forth A/B but my first impression was that it opens up the sound as if you're in a bigger environment, if I didn't know better I'd say it was like a subtle Dolby effect or an EAX effect in games. It's not something I'd been used to in headphones so it sounded odd at first but I've gotten used to it and it's pretty nice. It doesn't actually change the source material, tightly mic'd or 'closed' recordings or don't have added reverb or anything like that but ones that are meant to have an open sound expand beyond what one would expect from headphones.

I also did the cap-cutting mod on the one I'm keeping, actually I unsoldered them because leaving leads sticking out of the board doesn't suit my anal-retentive style I sort of did it before listening much but the thought of filtering anything right at the output stage didn't sit well with me. Both my speaker system and headphones are sort of bright, or rather non-bass enhanced - NS-1000M speakers and Grados SR-80s. I can see how people with those phones might not like the mod but if so they might be better off with other phones instead. The LT1364s may help in smoothing things out a touch too but it's hard to tell. The next mod will be a better volume pot for sure, the stock one works OK but with low impedance phones like the Grados the volume difference between channels at very low levels is apparent. I'd actually like to try adding an impedance switch across the headphone out but that's for the mod thread.

Lengthy post, just figured I'd share in case anyone else is having a similar issue.

[athenaesword]

oops nvm

[Garret Jax]

FOR PC USERS

I currently run my PC's optical output to a Zero DAC/AMP to Sennheiser HD-650 cans. The setup sounds pretty darn good. However, I may help a friend out by giving him the Zero and purchasing a new sound card - the HT Omega Claro Halo. The Halo has a built-in headphone amplifier and is supposed to be top-notch, but I wonder if it would sound better or worse than the Zero DAC/AMP I am using now.

Here's some Head-Fi discussion on the Halo.


Here's the product's homepage (lots of specs).

What do you think? The Zero cost a little under $200, the Halo costs a little over $200, and I would be helping out a friend if I do this. However, I do not want to replace the Zero with the Halo if the sound quality will suffer. I need some advice.

Thanks Head-Fi!
-Garret

[jsplice]

I'd be cautious of replacing your Zero with an internal sound card unless you've heard it first. This card doesn't even look like it's shielded, meaning it will be susceptible to a lot of interference going on inside of the computer case.

I certainly wouldn't replace such an acclaimed unit as the Zero with an internal soundcard with no shielding that you haven't heard. Just my opinion though.

[les_garten]

Originally Posted by Garret Jax

FOR PC USERS

I currently run my PC's optical output to a Zero DAC/AMP to Sennheiser HD-650 cans. The setup sounds pretty darn good. However, I may help a friend out by giving him the Zero and purchasing a new sound card - the HT Omega Claro Halo. The Halo has a built-in headphone amplifier and is supposed to be top-notch, but I wonder if it would sound better or worse than the Zero DAC/AMP I am using now.

Here's some Head-Fi discussion on the Halo.


Here's the product's homepage (lots of specs).

What do you think? The Zero cost a little under $200, the Halo costs a little over $200, and I would be helping out a friend if I do this. However, I do not want to replace the Zero with the Halo if the sound quality will suffer. I need some advice.

Thanks Head-Fi!
-Garret

Hi,
I have an HT Omega Stryker. They make great SC's and their support is unsurpassed. I am a contributor to that thread also. I had the same questions. I went with the Zero and feel it was the very smart move now. There is a ton more flexibility to the Digital out of the soundcard to the zero setup. I also don't have to climb behind the computer to futz with my headphone cable.

With the zero, you have a great customizable DAC, a Good customizable Head amp. You can change opamps, you can go out the Preamp of the dac to an external Headamp. Looking at all the sound card has to do, how can that little board compare to an external dac and headamp?

I will say that a Claro SC to the zero is a great combo and probably where I will eventually go, although I probably won't see/hear any difference between it and the Stryker I have now.

The biggest deal is that with the Claro, you are done and locked in. I also think that the Headphones, like Sennheisers and others will never be driven properly from the Claro, so you will be limited with how "Well", you can drive Headphones. I have HD650's and the more I throw at them, the better they sound.

The good side of the Claro.... Your spending days are over!

[sandchak]

[QUOTE
What do you think? The Zero cost a little under $200, the Halo costs a little over $200, and I would be helping out a friend if I do this. However, I do not want to replace the Zero with the Halo if the sound quality will suffer. I need some advice.

Thanks Head-Fi!
-Garret[/QUOTE]

Incidentally I had a chance to listen to both through Zero (un-moded) and Auzentech Meridian Sound card, at a friend's place (which I believe is one of the best med level sound card and had that some time back)

I dont have much idea about HT Omega Halo, but in compared to Claro, Meridian is far superior as it even allows opamp swap at both stages and just not the output stage.

I found the sound coming out of Meridian, close if not better than the unmoded Zero, in terms of seperation and dynamics, through his HD600, mind you, he has no graphic card (only onboard) and his hard disc is shieded in a seperate enclosure (two of the many factors that cause distortions in a PC).

All said and done, the Zero we know can be moded to ones taste and to a great level. which will easily surpass many soundcards including the Meridians.

It really depends how far one wants to go with the Zero mods. To me, standard Zero against Meridian, I found the latter tad better, but then I know the zero can easily surpass that with a few additions..

In any case, you have to listen and compare to make that choice..

I realize, this does not help as far as your question goes, but then you might look into the Meridians too, to my mind it is going to be tough for Halo to beat it..

[les_garten]

[QUOTE
What do you think? The Zero cost a little under $200, the Halo costs a little over $200, and I would be helping out a friend if I do this. However, I do not want to replace the Zero with the Halo if the sound quality will suffer. I need some advice.

Thanks Head-Fi!
-Garret[/quote]

One more consideration, the Zero setup can be moved around to other sources. The SC is the SC, soup to nutz.

[AudioPhewl]

Originally Posted by Garret Jax

FOR PC USERS

I currently run my PC's optical output to a Zero DAC/AMP to Sennheiser HD-650 cans. The setup sounds pretty darn good. However, I may help a friend out by giving him the Zero and purchasing a new sound card - the HT Omega Claro Halo. The Halo has a built-in headphone amplifier and is supposed to be top-notch, but I wonder if it would sound better or worse than the Zero DAC/AMP I am using now.

Here's some Head-Fi discussion on the Halo.


Here's the product's homepage (lots of specs).

What do you think? The Zero cost a little under $200, the Halo costs a little over $200, and I would be helping out a friend if I do this. However, I do not want to replace the Zero with the Halo if the sound quality will suffer. I need some advice.

Thanks Head-Fi!
-Garret

The card would be - IMO - broadly comparable to the stock Zero. Possibly slightly better, possibly slightly worse.

The real benefit of owning a Zero is how good it sounds with a little time and a few mods. I've got a modded Zero, and it would need to be a product of noticeably better sound quality for me to consider changing. Unfortunately, it would take much more money to have an appreciable increase in quality...

~Phewl.

[Garret Jax]

Originally Posted by AudioPhewl

The card would be - IMO - broadly comparable to the stock Zero. Possibly slightly better, possibly slightly worse.

The real benefit of owning a Zero is how good it sounds with a little time and a few mods. I've got a modded Zero, and it would need to be a product of noticeably better sound quality for me to consider changing. Unfortunately, it would take much more money to have an appreciable increase in quality...

~Phewl.

Thanks Phewl. What mods would you say are the best bang-for-your-buck? I have the OPA627AU and LT1364 in the headphone amp, but where should I go from here?

[Currawong]

Originally Posted by Garret Jax

Thanks Phewl. What mods would you say are the best bang-for-your-buck? I have the OPA627AU and LT1364 in the headphone amp, but where should I go from here?

A Moon HDAM for the DAC section. Make sure you ask for one with the extension leads.

[Ben Diss]

Originally Posted by DaMnEd

HA USB TO SPDIF (coax) 2902

Cheap and does what is required.

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?

[x_lk]

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

[helicopter34234]

The ZERO will make do if you have good headphones and haven't yet heard better, but wont in any way compare to adding a good few hundred dollars worth of amp will.

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.

[les_garten]

Originally Posted by helicopter34234

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.

[helicopter34234]

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?