Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp
Dec 24, 2008 at 4:53 PM Post #8,551 of 9,388
The LT1364 opamps came in (such great timing, a Christmas gift from Linear Tech?). Swapping out the old ones with the new ones was surprisingly very easy. I expected them to be jammed in their pretty good, but they slipped right out using a 2mm flathead.

The first thing I notice under the new ones is an increase in clarity and detail. The sound is less muddy compared to the old ones I think (hopefully its not just placebo). I only just put them less than twenty minutes ago upon writing this email, so I'll have to give them more time to break in. As of right now, I'm pleased with the swap. A definite improvement.

Now, I have one question unrelated to the opamps. As I was messing around on the inside, I noticed that one of the 4 big black blocks in the headamp/preamp section seemed a bit loose. It is the block on the left hand side when the Zero's front is facing you. When I say 'loose' I mean in comparison to the other three. When I tried to very gently wriggle the other three, they barely budged if at all, while the fourth one moved without much effort. Is this a concern?
 
Dec 24, 2008 at 7:29 PM Post #8,552 of 9,388
Quote:

Originally Posted by Currawong /img/forum/go_quote.gif
My take on the HDAMs was that the main difference appeared to be the soundstage (whether that is a function of a slightly different EQ or not I'm not entirely sure, but is quite possible) with smallest to largest going Sun < Earth < Moon. My reference tune was Jeff Buckley singing live, with him being more up-front with the Sun, and least so with the Moon.

With the HDAMs, give them 350 hours to burn in. The caps and transistors need it.



This fits perfectly with what I've found as well. I know my HDAMS have been well burned in, too, so the changes should all be "final." I'm thinking I just prefer a smaller soundstage/more forward presentation (which may make sense in the real world too - I like sitting up front at movies and concerts - even orchestral). The whole concept of soundstage is a bit of a mystery to me - I've heard all the explanations and such, but as far as what is more desirable or pleasing, I've yet to draw a conclusion. I try to avoid using it to describe things because a full understanding of it escapes me.

But based on your description of the soundstages of the 3 hdams, it makes sense - and I guess it means I like a smaller soundstage with vocals more "up front". Just as much though, I feel like the Sun gives me more detail from my Sennheisers - more of the attack and reverb of a guitar or bass string that I felt I'd lost when i sold my Grados. I also feel like I can pick out the drums more easily (I'ma drummer at heart) which is a lot of fun for me. I really enjoy this stuff - and to my ear it is what instantly calls out lossless vs mp3 or even hi-res audio vs CD audio.

Again, this is a preference thing, I just wanted to bring up that I am enjoying the Sun, since it seemed to be mostly written off quite some time ago. The consensus here seems to be that most prefer the Earth and Moon, so I just wanted to throw in that coming back to the Sun has been very enjoyable for me - and to nail down why so that new peeps can make the best decisions for themselves.

beerchug.gif
 
Dec 26, 2008 at 10:19 PM Post #8,555 of 9,388
It depends on your preference, the mod will increase treble, so if you have very bright cans you might find this mod not to your taste.
If you just clip the leg, you can easily put the cap back. I removed the caps in my zero right away, loved it .

Also, x2 votes for Sun HDAM, i might never get to hear my moon beforr my new DAC turns up, i can't seem to bring myself to take Sun out!
 
Dec 27, 2008 at 6:26 PM Post #8,556 of 9,388
Hi, I need some technical help from you guys..
Ive been trying to fix a problem with false contact in the decoupling caps area, and messing around with one of them, Ive touched with one leg the heathsink of a voltage regulator wich is under it (I did it with when the dac was running).
I think of a short circuit that burned something, maybe the voltage regulator (lm317) or maybe something else, because the sound now is so low that I can barely hear something at full volume of my amp. My uncle, which is an electrical technician, told me that a schematic will help to find out what could have happened, and if other components have burned. If someone can give me some tips about, even suppositions, or know if a schematic of the zero exists, please tell me!
Thanks a lot!
 
Dec 28, 2008 at 3:44 PM Post #8,558 of 9,388
according to the Lampizator site, the Headphoneamp stage is always in use. Is this true? I kind of believe it because when I switch the headphone amp on it sounds exactly the same as if it's switched off while going out to the RCAs.

I'm looking to bypass that all together. and use Just the Dac section of the ZERO. Can anyone confirm this?
 
Dec 28, 2008 at 3:48 PM Post #8,559 of 9,388
Quote:

Originally Posted by goorackerelite /img/forum/go_quote.gif
according to the Lampizator site, the Headphoneamp stage is always in use. Is this true? I kind of believe it because when I switch the headphone amp on it sounds exactly the same as if it's switched off while going out to the RCAs.

I'm looking to bypass that all together. and use Just the Dac section of the ZERO. Can anyone confirm this?



Just disconnect the headamp board since you have no use for it, presto, DAC only.
 
Dec 28, 2008 at 3:53 PM Post #8,560 of 9,388
Quote:

Originally Posted by DaMnEd /img/forum/go_quote.gif
Just disconnect the headamp board since you have no use for it, presto, DAC only.


SOrry I'm technically challenged, can you tell me where the Headphone amp section is located at?
 
Dec 28, 2008 at 3:55 PM Post #8,561 of 9,388
Quote:

Originally Posted by ads2 /img/forum/go_quote.gif
well, I have finally found the page that tal about the capacitors here Introduction to the Zero DAC and Headphone amplifier. - Head-Fi: Covering Headphones, Earphones and Portable Audio
So should I or not remove these caps ? any advice are welcolme.
thanks



I think those caps are there as prophylactics for your ears, lending you to less listening fatigue over the period of few hours. Some people are really sensitive to treble and might want to keep them on, or if you have really bright headphones from Grado, Beyer, or AKG.
 
Dec 28, 2008 at 3:58 PM Post #8,562 of 9,388
Quote:

Originally Posted by goorackerelite /img/forum/go_quote.gif
SOrry I'm technically challenged, can you tell me where the Headphone amp section is located at?


Sure:


The main (big) board is the DAC, the little one where the headphone connects and where the volume pot is located is the headamp/pre-amp board, I've put a red square around it for added visual help.

Just disconnect the cables that link that board to the main (DAC) one.
 
Dec 29, 2008 at 12:39 PM Post #8,564 of 9,388
Is it worth waiting for:
н¨ÍøÒ³ 1
THe DAC Compass, is this an alternative? Will it also do 24 BIT/192KHz?
 

Users who are viewing this thread

Back
Top