Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp
Jul 25, 2008 at 1:19 PM Post #4,501 of 9,388
Quote:

Originally Posted by Summer Jazz /img/forum/go_quote.gif
Hi Penchum,
Thanks for the detail review of the Zero DAC (on the 1st page) & the op-amp combo selection. I have ordered my Zero with the default op-amps (I’m on budget). The upgraded version is 2x OPA627 (on a adaptor) in the DAC section & 2x LT1364 in the headphone amp section.
After checking your review on the op-amp combo selection, it seems like I can also swap the stock op-amp to a single LT1364 in the DAC section & 2x LT1469 in the headphone amp section, am I right?
Is there a guide line or something to take note of regarding about swapping the op-amps on both in the DAC section & in the headphone amp section (other than to take note of single or dual channel in the op-amp)? In other words LT1364 in the DAC section & LT1469 in the headphone amp section & vice versa.
Thanks!



Quote:

Originally Posted by Enthusia /img/forum/go_quote.gif
You know you could of ordered the upgraded version and paid the same price by telling Lawrence your from head-fi.


Hey Summer,
Enthusia's right and I'm confused.
redface.gif


To answer the rest of your post, yes, you can put a "dual" Opamp in the DAC socket, as long as it is "unity gain stable". If you want to try the LT1364 in the DAC, it is recommended you put a heat sink on it, because it gets hot without one.
smily_headphones1.gif
As you found, there are many combo's to try and you may find one that suites you just fine.

The majority however, end up with the OPA627's in the DAC and LT1364's in the headphone amp after months of Opamp rolling. This is why Lawrence developed the "HeadFi Deal", so you folks would get a price break and not have to look all over the place for Opamps and spend months rolling them.
smily_headphones1.gif
 
Jul 25, 2008 at 1:22 PM Post #4,502 of 9,388
Hey guys a little help needed.
I am getting pretty loud pops from my headphones from time to time when listening to music.
This has happened about 3 times during yesterday and today.
One time I actually heard that when there was no music.
Could it be that the the RCA cable I use to hook it up to my soundcard's digital output is to blame?
Or is something wrong with the DAC?
 
Jul 25, 2008 at 1:24 PM Post #4,503 of 9,388
Quote:

Oh dear. AudioPhewl is not a happy bunny.

Quote:

Lawrence,

I am not happy. I will give you the benefit of the doubt for the time being, but if the matter is not resolved in a timely manner, I shall open a Paypal dispute and file a chargeback on my credit card.

My main issue is that only one channel of the DAC is working - the left one. The right channel is very quiet, but does have some output. I removed the case to check the OPA627s were correctly seated, but they are not there. Nor are the Linear Technology opamps in the headphone amplifier module. There is also a noticeable scratch on the metal casing.

I _specifically_ requested[email dated 3rd July 2008] the DAC with the opamp upgrades.

I now have the lower specification package, despite paying the higher cost. And not only that, it doesn't work correctly. It also took 2 weeks longer than originally discussed for me to receive the part.

Please let me know how to proceed from here.

Regards,

~AudioPhewl


What a total waste of time this is turning out to be. I know the guy has many happy customers in this thread, but he's seriously dropped the ball with my order from start to finish.

~Phewl.


To update the current situation, Lawrence has replied:-

Quote:

Dear Sir ,



The dac has been ran in for one day before shipping out, please check it carefully. May be due to some careless mistakes!



May be we have some cofusion in our email that we thought you only need adaptors for fabricate your own op amp.



If not happy , please return the dac in original condition and I refund the item cost to you.





Thank you very much !



Best regards,

Lawrence


My response:-

Quote:

Lawrence,

There is no mistake, the right-hand channel is significantly quieter than the left. If the left is at 100%, the right is at less than 20%. This happens whether it be through the headphone socket, through the RCA sockets as a line-out, or as a pre-amplifier.

My initial email to you clearly stated that I was looking for the Head-Fi modified unit, and I asked what the modifications were. Your first response states the modified unit, with opamp upgrades, costs $180 shipped. I confirmed that I would take one of these units - all these emails were sent on the 3rd June. I then enquired about the availability of blank SOIC->DIP adapters, and adjusted the amount transferred by Paypal to take account of these extra units.

Please check over your emails to confirm my intentions.

I will gladly return the unit in original condition. I do not want the item cost refunded. The unit was faulty as received, and the order incomplete. I either want the order "made good", by the shipment of a working unit with the upgraded parts as discussed, or I expect a full refund of the money transferred, less the cost of the SOIC->DIP8 adapters, which are as described.

I will need your shipping address, and confirmation that one of the above choices is acceptable to you, otherwise I shall start a Paypal dispute.

Regards,

AudioPhewl


I'll update you again with any response received.

~Phewl.
 
Jul 25, 2008 at 1:49 PM Post #4,505 of 9,388
Quote:

Originally Posted by katanka /img/forum/go_quote.gif
Somebody posted a link to this guys website a few posts back, i just though this pictured looked so cool



It looks like it's happy to see someone!!
biggrin.gif
 
Jul 25, 2008 at 2:53 PM Post #4,506 of 9,388
It's pretty cool...but remember in order for that mod to function, the head amp section has to be sacrificed in order to add the parts necessary for that tube to function. So it's a strict line out only DAC after that. How it sounds though...probably pretty darn good...

Would make no sense for my set up. The MK III adds the tubiness
smily_headphones1.gif
It's nice to see people taking this little dac/amp in different directions and being super pleased with the outcome.....
smily_headphones1.gif


Peete.


PS Pench...is that a 6N6P in your pocket or are you glad to hear me ?
biggrin.gif
 
Jul 25, 2008 at 2:57 PM Post #4,507 of 9,388
Quote:

Originally Posted by AudioPhewl /img/forum/go_quote.gif
To update the current situation, Lawrence has replied:-



My response:-



I'll update you again with any response received.

~Phewl.



Oh my.........that second response will be crucial.....that's what I'm waiting for..

Peete.
 
Jul 25, 2008 at 3:18 PM Post #4,508 of 9,388
Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif
Would make no sense for my set up. The MK III adds the tubiness
smily_headphones1.gif



I'm using a Yaqin 6J1 tube buffer, with Mullard tubes at the moment, with mine. [Upgrading to a tube preamp and SS power amp in the next month or so].

Seemed to make the bass a bit thicker, and expand the sound stage just a tiny bit. But then again it's hard to tell, which is doing what. As I added the buffer at about the 50 hour burn in mark, with the DAC. And have only put about 25 hours in burning in the Mullard tubes, and the DAC since then.

I just know it seems to be getting better all the time. My little Royd Minstrel speakers have never sounded so good
biggrin.gif
.
 
Jul 25, 2008 at 3:58 PM Post #4,509 of 9,388
Hi Nedman......right on...that little buffer is supposed to be a good one from what I hear from others that have one. I keep forgetting my MF X10/X-PSU (Pink Floyd mods) is in the mix when I use the MK III.......lol....(slaps forehead). Until the PF mod I wasn't all that impressed with it....

Peete.
 
Jul 25, 2008 at 4:56 PM Post #4,510 of 9,388
i'm in dilemma, I'm now in Malaysia which use 220v, however, I'm going to the US for my final year in college later next month. The bulk price in Malaysia is about USD120 shipped. So I'm really tempted to get Malaysian version as it's cheaper and more secure for me to get it. If that so, I would be having total abstinence from my first ever (dedicated) DAC for a year in the US.

I would like to ask whether i can buy power supply part for US voltage, and use it while i'm in the us. any idea? TIA!
 
Jul 25, 2008 at 5:56 PM Post #4,511 of 9,388
^The PSU is switchable. The switch is located on the rear of the DAC, 220/110v.

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif
Oh my.........that second response will be crucial.....that's what I'm waiting for..

Peete.



I'm pretty darned underwhelmed by the response. Not really as enthusiastic as I was hoping for...

PS - anyone have any idea why the thread I started about OPA827 seems to have been removed?

~Phewl.
 
Jul 25, 2008 at 6:02 PM Post #4,512 of 9,388
I think he was hoping it was user error.......I don't think that's his current view or it shouldn't be....we'll soon see...

Peete.
 
Jul 25, 2008 at 8:17 PM Post #4,514 of 9,388
Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif
It's pretty cool...but remember in order for that mod to function, the head amp section has to be sacrificed in order to add the parts necessary for that tube to function. So it's a strict line out only DAC after that. How it sounds though...probably pretty darn good...

Would make no sense for my set up. The MK III adds the tubiness
smily_headphones1.gif
It's nice to see people taking this little dac/amp in different directions and being super pleased with the outcome.....
smily_headphones1.gif


Peete.


PS Pench...is that a 6N6P in your pocket or are you glad to hear me ?
biggrin.gif



Ya exactly! That is one happy Zero.
smily_headphones1.gif
 
Jul 25, 2008 at 10:41 PM Post #4,515 of 9,388
Quote:

Originally Posted by AudioPhewl /img/forum/go_quote.gif
^The PSU is switchable. The switch is located on the rear of the DAC, 220/110v.



I'm pretty darned underwhelmed by the response. Not really as enthusiastic as I was hoping for...

PS - anyone have any idea why the thread I started about OPA827 seems to have been removed?

~Phewl.



It was removed ? What section was it in...maybe it was moved ?

Peete.
 

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