Think of it this way. The one opamp at the 3'o clock position is the DAC opamp. It amplify the signal and gives the output to the preamp (RCA) and also the headphone amp. Headphone opamp is near the jack and they are 2 of them (stock is NE 5532).

If u change DAC opamp, it will affect the sound at both the RCA and headphone amp. If u change the headphone opamp, it will only affect headphone sound (not affect RCA).

So far, some has said the OPA Earth / Sun at the headphone has produced good results.

Well I have 1 OPA Sun if u want can borrow and test. That will give you better dynamics, more forward vocal and clean.

Trust me, ZERO with OPA will give you a run of your money.

Time to get a line conditioner ? sometimes the line conditioner comes with those sockets that is universal which is very useful.

I guess u have missed the free 1 to 1 promo. But u can talk some of the forumer here who might sell u a opa earth or sun. that would be hassle free.

Hi Rav,

so is yr humming problem still around. Suggest u grab a multimeter and start poking around.

Just to share with you guys one of the mat salleh review of the HDAM.

一个外国网站对本人的HDAM评价


Texture
Positioning
Soundstage
Resolution / Detail
Dynamic/ Attack

HDMA
5
5
4
5
5

Super Op-Amp
4
4
5
4
5

AD825
3
3
3
4
4

OPA627
4
3
3
3
3

OPA2604
3
2
2
3
3

NE5532
2
1
1
2
3

Hi,

Use the multimeter, check the tightening screw with the earth wire.

Check the cdp casing to earth.

What is your incoming voltage ? 240V

HI Rav,

My suggestion is to try to get a clean power source and try again. if u have inspected the pcb for any 'shorts' then just measure few of the output voltage like +- 15V, 5V, 3.3V. that would be faster.

I have thinking how to improve the sound of ZERO. Hopefully when the components come I will get some testing done.

The latest news on OPA using for Headphone has some bad news.
The output transformer is not able to supply enuf current for the headphone section.

Good news is u have got good OPA in your hand and audio-gd is running out of stock. plus some improvement is being done to the power supply stage.

Hi Kwek,

I hope the new OPA will blow you off from the couch, and I can recommend you another OPA to get you back to the couch. That is OPA Moon.

Available after next week.

This post has been edited by ccschua: Sep 5 2008, 12:26 AM

the power supply mod. u may read this long winded story.
http://www.head-fi.org/forums/f5/review-ze...8/index628.html

To all who is going to test the zero. Do listen intensely at this initial impression, then at 50 hours and then at 250 hours. u will notice some changes in the sound, like a girl growing up to pretty women.

Welcome to the delicate world of HIFI.

Volex 17604 can be obtained from Farnell. I tried it out on amp, expected some positive outcome but was disappointed.

So since it has not done well on the amp, I made no further attempt on dac.

This is kind of contradicting what Audio circles guys was saying as well as advice by Empire23.

Perhaps I need to modify the stock Volex 17604 male wall plug to Marinco/Hubbel.

As I have mentioned in the previous posts, when u listen to OPA (or they called it HDAM at head-fi), they will be changes in sound quality. The soundstage staging also narrowed, widened, narrowed and widened, strange isnt it.

Here is Pricklely peete review
--

Talk Talk was intelligible (no easy feat!) ... etc.

LOL...I saw them live a long long time ago and still can't figure just WTF that was exactly.....

The HDAM goes through some rather dramatic stages before it settles down for good...as you've just witnessed. Like you, I listen for almost all the time the amp is on so I'm quite familiar with the HDAM SQ signposts.

You'll hear it flutter back and forth between , rolled off bass, then rolled off highs, the mids well recess and come back, the sound stage will deepen considerably in the latter stages, mind you...the best part of all is the relaxed presentation, as in effortless delivery, that will increase to gigantic proportions. Excellent transient speed (with the cap tweak) decay that lasts as long as the note is held, hall reverb trails heard perfectly while crescendos crash all around you...great stuff Wait till you hear this with HD650's...


The synergy between the HDAM and Zero is fantastic.
--

Oh yeah. I am also getting some Volex for DAC. May be when it arrive I will give it some listening. My Volex now is connected to the filter.

The cap mod will be done but at a latter time. audio-gd thinks the cap mod is only for those uses long cable to connect the OPA.

Any how audio-gd new product come with the cap. it is a EVOX 0.68uF, which is natural and soft sounding. They are 2 of them. see the photo.

I wonder when is Empire23 back, cos I run to bottleneck regarding ZERO DAC mod.

This post has been edited by ccschua: Sep 7 2008, 01:39 PM


Attached thumbnail(s)

As much as we know Earth is neutral and natural, I believe u review will also be neutral. I guess yr listening has improved a lot since spending $$$ hanging on to lowyat.net.

Yes now its time to rock and roll. Anyone can post some photo here of your OPA and setup.

This post has been edited by ccschua: Sep 9 2008, 07:12 PM

use a long nose to remove the stock OPA. u will see a semi and make sure it is in the sam orientation. Godluv posted this in the earlier thread.

Check carefully, there is a semi circle on any opamp, which is the head.

This head must point towards the back of ZERO.. another mistake will burn down the earth.

Hi kwek,

Have u got the OPA.. is it cooking now ...


which one u burn in \first. i guess it must be earth.

Hi guys,

if u want some slight improvement, try the Volex cable. they is a slight improvement in terms of life vivacity, separation and bass department. of course, u need to listen critically to hear the difference.

http://my.farnell.com/1252871/connectors/p...equestid=161406

This post has been edited by ccschua: Sep 9 2008, 10:51 PM

Where are u guys now, is it busy listening to OPA.

Let the reviews floodgate open.