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

[DaMnEd]

Originally Posted by electropop

Any good place to get the HDAM-module from? It's probably an easy DIY since so many have done it .. hehee..

Thanks!

-K

Audio-GD

I recommend you read this: Introduction to the Zero DAC and Headphone amplifier

[les_garten]

Originally Posted by electropop

Thanks les_garten! I'll mostly be using my AD2000's which are 40ohm. But if Grado's present an audible hiss, they will probably too

Well, since it's a secondary rig, it won't matter

I'll be ordering my Zero very soon.

Any good place to get the HDAM-module from? It's probably an easy DIY since so many have done it .. hehee..

Thanks!

-K

I don't know if it would help or not, but I believe there are impedance plugs for head amp phono plugs to raise the impedance. Maybe that wold help with the Hiss?

[MadMan007]

Originally Posted by x_lk

My Zero does give a audible hiss through my Grado SR60, when no music playing, volume is 3 o'clock and beyond.

I use mine with SR80s and yea when you crank it up there is a little hiss. But there is NO WAY I'd listen to it at those volume levels, I would be seriously afraid of damaging my hearing well below that volume position. I probably never go beyond 8 o'clock for normal listening and maybe 9 o'clock for short periods of rocking out. i do think a low-impedance mod or option would be useful just to have more usable volume range.

[electropop]

Originally Posted by DaMnEd

Audio-GD

I recommend you read this: Introduction to the Zero DAC and Headphone amplifier

Thank you!

Very useful information. It seems the site can be 'translated' adequately.. I will look further into it once i have the amp and some free time!

Les_garten, I've heard of the plugs, but the one's i've found googling are either as expensive as the Zero or just not available in Finland, at least in general..

Thanks for input and good night!

-K

[closdubois]

Originally Posted by Penchum

With all this troubleshooting going on, I thought it would be a good idea to share some of what I know about the Zero, from a slightly different stand point. Many of you don't know this, but the Zero has been sold to members of HeadFi, dating clear back to August of last year. That is a year and three months!!

Late last year and early this year, Lawrence was the only trusted seller who was "bench testing" his Zero's prior to shipment. The Zero factory was putting out some decent units, and the failure rates were much better than we could get from a US manufacturer. Then, things just seemed to change somehow. Other sellers were popping up, selling quantity to make their profit. Once Lawrence lowered his prices and made deals to compete directly with them, I'm "pretty" sure bench testing went away, except in cases where soldering was involved, like when the Alps pot upgrade was done in house.

Then, we started to notice problems with the cleanup and QC of the boards, prior to final unit assembly. It looked like sloppy work, but I think the cleaning/QC was simply NOT DONE before assembly. It seemed like the assembly line just dropped this cleaning/QC step, opting to shove them out the door quicker. I wasn't impressed. The factory owns this problem 100%. Then, we started to notice the upgrade Opamps not being installed correctly, like they were an afterthought or something. Chalk this one up to final QC. The "seller" owns this problem 100%.

Considering all these things, it seems to paint a "not so hot" picture for the makers and sellers of the Zero. However, all of this is only ONE part of a much bigger picture.

The Zero factory sells Zero's in batches of 50 units, to resellers that sell on eBay or their own web site stores. We already know this part. The part we don't see, is the amount of Zero's that are sold to stores in China. According to two such stores, they are selling Zero's like crazy to the public in China! Way more than the amount of Zero's being sold around the world! So, when you think about production of the Zero's, you have to factor in a much higher quantity demand being put on the factory. Those boys must be jamming big time! We also have to consider what happens to our Zero's during shipping. It is the great unknown, but indicators show that smaller boxes are being tossed around pretty hard. We can't escape this variable, if we want a Zero.

At the end of the day, the failure rates on the Zero's as a whole, are very good. Of all the HeadFi'ers buying Zero's, we always hear about the ones that have issues. These amount to a very small portion of the overall HeadFi numbers. Add in the units that need help after shipping, and you still have a very small number.

So I guess what I'm trying to say, is that the majority of us who order a Zero, will have a decent Zero without problems. The problems noted above were spread out over an entire year! Considering it is a budget DAC/Amp and it was shipped half way around the world to our door steps, it is great that the Zero has had so much success. The price point has saved us a bunch of cash, and the Zero's performance has put higher priced units on notice!

I still believe buying a Zero is a safe bet. Thanks to everyone's hard work in this thread, the small number of problem Zero's identified here, get fixed by the owners, and very, very few will ever have to return their Zero's to China for a fix. This thread has just about every fix known, and the help you can get here is some of the best I have seen on HeadFi. With this kind of backing, I would buy another Zero in a heart beat! You guys are the best!!

Pench

Pench:
Went back on the site to see if I could find a description of or diagnosis for the problem that has cropped up with my Zero. After reading your review I purchased it modded with the 627 and 1364 ops and Alps pot from Lawrence in early Aug. this year. Burned it in for 150 hrs and then began listening. Enjoyed thoroughly for the past 3 months.

Then last week, I heard a funny swishing sound in my phones and then the power light and the optical light went out but the green phones light stayed on and there was no sound in my phones. I turned the power button off immediately. Then I pushed the power button back on the lights came back on and I engaged the phones button and the phones light lit up and I had great sound again. This happened 3 times in about 15 minutes. The last time it happened I turned everything back on and then tapped lightly on the side of the chassis and this time all the lights went out.

I've only gone back about 15 pages from the last page of posts when I found your above quoted comments. I don't know if this problem has been mentioned prior but would be grateful if anyone has any suggestions. As is probably obvious, I'm no electronics wizard. Thanks for any help.
Closdubois

[K3cT]

Can anyone comment on how the Moon HDAM stack against the Earth? From Currawong's reply a few pages back and my other research, it seems that the Moon has a great soundstage while the Earth has a natural and flat response. Is soundstage the only thing the 'Moon' has going for it? I'm looking to smoothen the treble and upper mids and control the bass for the Denon D2000.

As a side question, how would a Zero with a HDAM in the DAC section fare against the D3 Phyton?

Side question, how

[MLev]

Now my Zero has LT1364 on HP and Earth on DAC.
Most of the time I listen HP, on rare occasions I use DAC.
I wonder how long does it take to complete the burn in process for the Earth using the DAC on rare occasions.
Is the Earth active and burning in while I'm listening HP?

[Henmyr]

Originally Posted by MLev

Now my Zero has LT1364 on HP and Earth on DAC.
Most of the time I listen HP, on rare occasions I use DAC.
I wonder how long does it take to complete the burn in process for the Earth using the DAC on rare occasions.
Is the Earth active and burning in while I'm listening HP?

If you are listening to the Zero internal headphone amp you are also using the Zero internal dac. You can not use the headphone amp without it's dac.

[Penchum]

Originally Posted by closdubois

Pench:
Went back on the site to see if I could find a description of or diagnosis for the problem that has cropped up with my Zero. After reading your review I purchased it modded with the 627 and 1364 ops and Alps pot from Lawrence in early Aug. this year. Burned it in for 150 hrs and then began listening. Enjoyed thoroughly for the past 3 months.

Then last week, I heard a funny swishing sound in my phones and then the power light and the optical light went out but the green phones light stayed on and there was no sound in my phones. I turned the power button off immediately. Then I pushed the power button back on the lights came back on and I engaged the phones button and the phones light lit up and I had great sound again. This happened 3 times in about 15 minutes. The last time it happened I turned everything back on and then tapped lightly on the side of the chassis and this time all the lights went out.

I've only gone back about 15 pages from the last page of posts when I found your above quoted comments. I don't know if this problem has been mentioned prior but would be grateful if anyone has any suggestions. As is probably obvious, I'm no electronics wizard. Thanks for any help.
Closdubois

I would be checking the power (and all) connections on the inside. The tapping the side of the case seems like a loose connection somewhere.

[Currawong]

Originally Posted by K3cT

Can anyone comment on how the Moon HDAM stack against the Earth? From Currawong's reply a few pages back and my other research, it seems that the Moon has a great soundstage while the Earth has a natural and flat response. Is soundstage the only thing the 'Moon' has going for it? I'm looking to smoothen the treble and upper mids and control the bass for the Denon D2000.

If you want to control the bass in the D2000s, you should Markl-mod them. Changing HDAMs wont do that for you.

[Penchum]

Originally Posted by x_lk

My Zero does give a audible hiss through my Grado SR60, when no music playing, volume is 3 o'clock and beyond.

Originally Posted by MadMan007

I use mine with SR80s and yea when you crank it up there is a little hiss. But there is NO WAY I'd listen to it at those volume levels, I would be seriously afraid of damaging my hearing well below that volume position. I probably never go beyond 8 o'clock for normal listening and maybe 9 o'clock for short periods of rocking out. i do think a low-impedance mod or option would be useful just to have more usable volume range.

Hi Guys!

Excellent point being made here. With no music playing, turning the amp up until you hear amp hiss at the higher end of the volume scale, means absolutely nothing (for real world listening). Unless you are stone deaf, you'll never listen to headphones at that higher level of amplification. If you do, your hearing will be damaged permanently, in short order.

The worry some folks have with lower impedance headphones, is that they will have constant hiss at any volume, due to impedance mismatch. I haven't heard of this problem with the Zero's built in headphone amp so far. The last time I checked, the Zero was still advertised as 32-600 ohm capable. Below that range is still an unknown area, as far as I know. Maybe some other Zero owners with headphones below 32 ohms, can chime in and let us know for sure?

[K3cT]

That's a very possible option but I still need to look for a replacement for the fibreloft. Still, I think I'm missing something since right now I'm listening the D2000 right out of a FiiO and my XPS' headphone jack.

Anyway, can you comment more about the Moon HDAM, Currawong? I'm still at loss on what units to order. Right now I'm thinking of either the Earth or Moon at DAC and stock op-amps at the amp.

[Penchum]

Originally Posted by K3cT

Right now I'm thinking of either the Earth or Moon at DAC and stock op-amps at the amp.

I would recommend the "earth" in the DAC position. It has the most neutral signature, which many of us have found to be the best for DAC use. I'm using LT1364's in the headphone amp section, which works very well with my HD-650's.

[Currawong]

Penchum: What have you thought so far of the Moon?

K3cT: The Earth is the safe bet, but I don't think you'd be disappointed with either. The Moon I'd say was more relaxed-sounding, but that could also be described as being the result of better soundstaging (possibly a subtly different EQ giving that feeling).

[Ben Diss]

I'm a little lost on this whole HDAM thing. I apologize if this was covered somewhere in the last 800 pages of this thread.

- What does HDAM stand for?
- How does the Earth or Moon compare to the OPA627?
- Where does one buy and how does one install LT1364's?

I bought a Zero from "wz" that has the OPA627's and I'm loving it. If I can further improve the sound, I may just do that. I'm thinking about doing the Franken caps upgrade as well.

Thanks.