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

[Currawong]

Originally Posted by Syu

Hi,

I read Introduction to the Zero DAC and Headphone amplifier. - Head-Fi: Covering Headphones, Earphones and Portable Audio and was interested in it. Are there some comparative reviews between The "as far as you can go without soldering" ZERO and other famous AMPs or DACs like HD-1L, m902, P-1, Darkvoice 337, Benchmark DAC1 or Lavry DA10?

I have a Lavry on the way, so I'll let everyone know. The only comparison I've done is with an Apogee Duet, which it was fairly equivalent to if using just opamps. Using the HDAM, it's better than the Duet. I highly doubt it could out-perform a Benchmark DAC1 or Lavry. It would be interesting to see how far it can be made to go after mods though.

Originally Posted by StratCat

My opinion:

A stock Zero can drive the K701 well enough to get a feel for it's sound-signature, and you can enjoy it for simple musical enjoyment, but I would likely use it as a starting point if interested in doing serious critical listening. I'm on the fence with this opinion, because, TBH, I currently DO thoroughly enjoy my K701's on my Zero's HP, and I do attempt to do some critical evaluation, too.

So honestly, I could easily live with this combo if I had to, and would likely remain happy if not hanging out here on Headfi!

Seriously!

But, TBH, I'll only be able to accurately describe the Zero's HPA vs an external amp when I get my LD 1+ that I ordered recently. The Zero HPA + K701 seems to be a perennial question around here, and hopefully I'll soon be able to provide a more critical response.

HTH

I'm sure I'd be still enjoying my old Quart 55Xs if I'd just bought a stock Zero in the first place. At the least, you're missing out on a lot of soundstage not having a dedicated amp.

[StratCat]

Originally Posted by Currawong

[...]

I'm sure I'd be still enjoying my old Quart 55Xs if I'd just bought a stock Zero in the first place. At the least, you're missing out on a lot of soundstage not having a dedicated amp.

Hi Currawong -

I'm not sure I understand what your implying.

Are you saying you would NOT recommend using the stock Zero's HPA as a way to get started?

[Pricklely Peete]

Originally Posted by StratCat

Can't help you there (yet). But I do know using the HPA will definitely load your LT1364's (Oestensibly assisting any burn-in).

I'm not sure if the vol pot in pre-amp mode adjusts the gain in the DAC or HPA op amps.

You could test this by removing the LT1364's leaving the sockets unpopulated, and seeing if you can adjust the volume in pre-amp mode. If you still can, then obviously the LT1364's are out-of-circuit in pre-amp mode and you'll have to drive some phones to load the LT1364's.

Does this make sense?

Edit: Oops...hope I'm not stepping on your toes, Peete

Don't worry about it SC.

I'm almost certain the opamps in the H/Amp have to be installed in order for the circuit to function. I'm also willing to bet the LT1364's are responsible for gain in preamp mode. I believe the dac section opamp is fixed level gain for the analog output in pure DAC mode.

I could be wrong about that, but makes the most sense to me.

Can anyone confirm the configuration of the H/Amp opamps when engaged ( to drive either output ) ?

Peete.

[StratCat]

Originally Posted by Pricklely Peete

I'm almost certain the opamps in the H/Amp have to be installed in order for the circuit to function. I'm also willing to bet the LT1364's are responsible for gain in preamp mode. I believe the dac section opamp is fixed level gain for the analog output in pure DAC mode.

I could be wrong about that, but makes the most sense

Agreed.

That makes the most sense to me too, Peete.

If no one answers this definitively by the time I get my LD 1+, I'll check it out using the method I stated. I'd really like to learn more about the architecture and signal path of my Zero, and the new amp, too. I get the feeling the LD 1+ is going to be a nice compliment to the Zero WRT rolling and modding on-the-cheap...it has an op amp stage, along with the tubes, too!

[cybertron]

Well, its been a little while since I read this thread but I did a while back and I hope my information is still accurate. I just ordered my Zero with op amp upgrades, Alps pot, and HDAM from Lawrence. I hope that was a wise choice.

[Pricklely Peete]

Originally Posted by cybertron

Well, its been a little while since I read this thread but I did a while back and I hope my information is still accurate. I just ordered my Zero with op amp upgrades, Alps pot, and HDAM from Lawrence. I hope that was a wise choice.

A wise choice indeed. The Burson Audio cap mod should be done right away to your HDAM if you have a good 1uf >50V rating film and foil cap (or NOS PIO etc).

The difference it makes with the HDAM is well worth the effort. It's only drawback is burn in time required at 350 hours.

The tweak seems to give the HDAM that last bit of refinement needed for decay, transient speed, cymbal attack and decay as well as highly controlled macro and micro detail, dynamics etc...it also seems to add to the quality of bass and it's delineation. 3D sound stage is also improved a little.

Penchum has been studying this seemingly innocuous mod at length and is better placed to comment further. Take it away Pench

Peete.

[Currawong]

Originally Posted by StratCat

Hi Currawong -

I'm not sure I understand what your implying.

Are you saying you would NOT recommend using the stock Zero's HPA as a way to get started?

Not at all, just putting things into perspective. I used Quart 55Xs out of my Mac's headphone output for over 10 years, which is a crazy thing to do by head-fi standards, as they are painfully hard to drive headphones with massive diaphragms, totally unsuited to the role I was using them. However, I liked them a lot. When I first started into buying head-fi gear, I got my Little Dot MKV, followed by re-cabled K701s. I was arse-backwards in a sense because the 701s revealed that my computer as a source sucked, seriously. After the Apogee Duet came the upgraded Zero after I realised the Duet was to dry and analytical-sounding for the K701s. What I'm saying is, if I'd gone in reverse, and bought the Zero upgraded at first, it would have satisfied me a lot with my Quarts possibly without me experiencing what effect each component in the chain has.

People often ask "Will the Zero drive my headphones ok?" - What do they mean by "ok"? It's rather like all the threads where people are talking about buying K701s for their soundstage when they are not going to plug them into an amp or use a source that will allow the K701 to have a big soundstage.

[StratCat]

Originally Posted by Currawong

Not at all, just putting things into perspective. I used Quart 55Xs out of my Mac's headphone output for over 10 years, which is a crazy thing to do by head-fi standards, as they are painfully hard to drive headphones with massive diaphragms, totally unsuited to the role I was using them. However, I liked them a lot. When I first started into buying head-fi gear, I got my Little Dot MKV, followed by re-cabled K701s. I was arse-backwards in a sense because the 701s revealed that my computer as a source sucked, seriously. After the Apogee Duet came the upgraded Zero after I realised the Duet was to dry and analytical-sounding for the K701s. What I'm saying is, if I'd gone in reverse, and bought the Zero upgraded at first, it would have satisfied me a lot with my Quarts possibly without me experiencing what effect each component in the chain has.

Ah, O.K., I was confused...it would seem we ARE singing off the same page after all.

People often ask "Will the Zero drive my headphones ok?" - What do they mean by "ok"? It's rather like all the threads where people are talking about buying K701s for their soundstage when they are not going to plug them into an amp or use a source that will allow the K701 to have a big soundstage.

Exactly. To sound "reasonable" is tremendously subjective, like so much in audio.

I think perhaps the best way for me to approach responses to questions like this in the future would be to inquire as to where the poster is currently, gear and listening wise, and where the poster *thinks* s/he'd like to go (their desired end result), since we have a pretty disparate group here in Headfi WRT current listening perspectives and expected upgrade results.

I was very fortunate in that nearly immediately upon entering this hobby I realized I needed an inexpensive "sacrificial" test-bed in order to successfully demo and evaluate cans, starting with thier purchase firstly, and then I could fill in the rest of my system to fit my chosen can(s).

Funny thing though, now that I have the cans I like, I don't see myself sacrificing the test-bed anytime in the too near future!

Thanks again for the reply.

[AZNracerx1989]

How do you guys think this DAC will work with my home audio setup? I will use my AMP10 from 41hz.com and a dvd player as a source. Does the ZERO make a good preamp+ DAC or is it strictly good for only headphones?

High Grade 24bit/192khz DAC with fully assembled kits - eBay (item 120314358106 end time Oct-13-08 01:00:00 PDT)
or
http://cgi.ebay.com/High-End-24bit-1...d=p3286.c0.m14
I saw these and it is made by the same guy I think.. Would that be a better option?
Thanks

[Currawong]

Those kits require a box to put them in, which you'd have to modify, and a power supply. The Zero just requires that you plug it in and turn it on.

The Zero is the same as a headphone amp as it is a pre-amp. The output is just directed depending on whether you've got headphones plugged in or not.

[seaice]

Hi all!

I was just delivered Earth, Moon and Sun v2 HDAMs several hours ago. I have tried to compare Sun and Moon in the DAC section and I must say that I am impressed by the sound of both. The overall improvement over the OPA627AU is really huge. At first listen, all is improved in all frequencies - the texture, space, details, musicality... Now I have some hard work to do in the next several weeks - to listen and compare the HDAMs

My first impressions (only after 2 hours on Moon and 2 hours of Sun v2) - Zero with HDAM in DAC > MAC AgQ IC > LD MKV > Sennheiser 600 (with Cardas cable):

1. Both HDAMs are much better than OPA627au.

Comparison: (please take the following information rather as a quick first comparison between Moon and Sun v2 and not as a general characterization of their sound, even if it can say something about this)

2.Moon: very smooth, highly detailed and balanced sound, music (jazz) flows very consistently with no weak point, applaus passages sounds much more real than Sun

3. Sun v2: less smooth, less balanced, more dynamic (I am not sure yet if in all frequencies), more "impact" of percussions, more action, "sharper" sound, but sommetimes maybe too sharp for my ears (i.e. saxophone and persussions), applaus is considerably worse/not so real as with the Moon

From Sun v2 and Moon I personally prefer the Moon much (more), especially because of its superb balanced, non-disturbing, solid smooth, very detailed and dynamic sound at all frequencies at the same time... On the other hand, there is something about the Sun than doesnt fit to my ears (or to my listening chain), maybe the "sharpness", maybe the less balanced sound, I am not sure yet... I must confirm this and more in the long term listening. And something can change over time, of course. Consider, I have only 2 hours listening experience with both HDAMs (same music for comparison).

More testing in progress...

Enjoy my english If something unclear, tell me

[bundee1]

You're English is good enough to give us a great impression of those 2 HDAMs. Have you tried the Earth yet? My unit arrived 5 minutes ago so Im letting the Zero rest while I make a cradle for it.

Thank you for the first impressions.

[seaice]

I am testing the Earth just now (2-3 hours). I must say, that at first listen it is the most neutral HDAM of this trio (in the very positive way - I do not hear any weaknesses so far). In the near future I will focus on Earth vs. Moon comparison, because these are my favourite HDAMs for now - though they sound differently, neither has any weakness to my ears (setup). What is the Sun concerned, there is something that I sense as little, very little obtrusive (but even the Sun is still better than OPA 627). I am not sure what it is, I must sometimes listen several albums that I know exactly note by note... And there is still many I plan to test with these HDAMs - Senn 580/650 (with ordinary cable), AKG K701...

[cybertron]

Hmm, was just reading Currawong's introduction to the ZERO and I fear I may have made an impulsive purchase. Here is my setup, maybe you guys can tell me if i should have just gone with an amp.
my primary source is my computer using the crappy onboard Realtek soundcard. From there I go optical cable to my Logitech Z-5500 speakers, and i have my ATH-A900LTD's plugged into the z-5500 control module.
I've been relatively happy with this setup but I do not have anything else to compare it too. Would I have been better off just getting a Little Dot, or other amp? I spent $250 including shipping for my updated zero w/ alps, 1 hdam, and opamp upgreade.

[AZNracerx1989]

Originally Posted by Currawong

Those kits require a box to put them in, which you'd have to modify, and a power supply. The Zero just requires that you plug it in and turn it on.

The Zero is the same as a headphone amp as it is a pre-amp. The output is just directed depending on whether you've got headphones plugged in or not.

I don't mind making a case. And those transformers included are ready to plug into the wall. How do the DAC performances differ? Are they the same chip? How would the Zero DAC compare to say a $800 DAC?