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

[Penchum]

Originally Posted by oatmeal769

Aren't they awesome? I'm loving mine!!

If I have one of those weak moments, where I start to wonder if my tube changes are past the point of diminishing returns, I always go back, drop in my M8161's and listen for a couple of days. They bring "wholesomeness" to the sound signature and "re-set" my brain for further critical listening. This speaks "volumes" about their impact on my perceptions. They bring order to the audio chaos in my mind. There are tubes that sound better to me, but none of them can do what the M8161's can do.

[katanka]

Thanks for the Heads up on the chips oatmeal769.

And a big thank you to everyone here on this Zero forum. Especially to Penchum . With out this i would have been lost. When i first joined Headfi, i was overwhelmed by all the many different DACS/AMPS and Headphones. Getting the zero is a good starting point, and is nice that you can chop and change the internals to get different sounds. Before i read this forum, i was dead set on getting a EMU 0404, and now i am very happy with my ZERO. 18 hours of burn in so far.

Now i need to try and get some grado 225's

[Hardflip]

Originally Posted by oatmeal769

The first posting is from Tube buyer. I bought from him also, and am not at all convinced they are genuine. The ones I have look identical to this new ad. The serials are different, and suspect as well, I.E. too many characters. This from the TI website:

http://focus.ti.com/graphics/aap/packages/p-008-10.gif

Y Last digit of the year assembled (e.g. 0=2000, 1=2001)
M Month assembled: (1=Jan, 2=Feb, 3=Mar, 4=Apr, 5=May, 6=Jun, 7=Jul, 8=Aug, 9=Sept, A=Oct, B=Nov, C=Dec)
LLLL Lot Trace Code: May vary based on the size of the package and available space to put the characters. Some of the smaller packages do not have room for the full LTC and use an abbreviated version.
S Assembly Site Code
O Pin 1 Indicator

Not to mention the pricing is suspect as well.

The other ad looks much more legit.

yet from the page you use to dismiss the tube_buyer opamps, it clearly show there are NO opa627bp with the BB logo that contain only a dimple. There are 3 with the BB logo and all have notches on the side, with one having the notch and a dimple on the lower left.
IMO, this is a lot better to go than a code that could have been modified many times over the years. Plus, the site itself says they might vary depending on available size.

[Penchum]

Originally Posted by katanka

Thanks for the Heads up on the chips oatmeal769.

And a big thank you to everyone here on this Zero forum. Especially to Penchum . With out this i would have been lost. When i first joined Headfi, i was overwhelmed by all the many different DACS/AMPS and Headphones. Getting the zero is a good starting point, and is nice that you can chop and change the internals to get different sounds. Before i read this forum, i was dead set on getting a EMU 0404, and now i am very happy with my ZERO. 18 hours of burn in so far.

Now i need to try and get some grado 225's

Thanks for the kind words! The members who post here in the Zero thread have been totally great! They try things, communicate well with each other and keep me jumping! With the hours you have going, this weekend should bring about changes you are going to like.

[Penchum]

Originally Posted by Hardflip

yet from the page you use to dismiss the tube_buyer opamps, it clearly show there are NO opa627bp with the BB logo that contain only a dimple. There are 3 with the BB logo and all have notches on the side, with one having the notch and a dimple on the lower left.
IMO, this is a lot better to go than a code that could have been modified many times over the years. Plus, the site itself says they might vary depending on available size.

This is why I said in an earlier post, that it will come down to how a pair sounds after purchase. Too many variables for us to "lock down" true fakes. If someone is really concerned, they should get the OPA627AU's already soldered to an adapter. The cost is OK and the sound is excellent.

[oatmeal769]

Originally Posted by Penchum

... they should get the OPA627AU's already soldered to an adapter. The cost is OK and the sound is excellent.

Where did you say we could get these? I'm going to get a set. Reading I've done elsewhere confirms what you said about no audible difference between 'AP' and 'BP'

I hear little to no difference between the stock opamp, and the supposed 627BP sets I have now. I believe they are fakes.

[Penchum]

Originally Posted by oatmeal769

Where did you say we could get these? I'm going to get a set. Reading I've done elsewhere confirms what you said about no audible difference between 'AP' and 'BP'

I hear little to no difference between the stock opamp, and the supposed 627BP sets I have now. I believe they are fakes.

Lawrence sent me a test set of OPA627AU's. He has some for sale, but I don't know the completed cost. Drop him an email. One thing, these are the very small AU's, which are soldered to an adapter, one underneath and one on top of the adapter. They are not AP's, which look identical to the BP's. I don't have a pic up yet, but I'll try to get that done this weekend.

[tinseljim]

Those are the kind I have! Yep one on bottom one on the top, very cutesy. Also way easier to plug in and out. But I'm slowly beginning to think that I like the sound of the LT1364s a bit better. At least on my system they sound better in the dac section and i have two in the amp section as well.

if this continues to be true then i will soon have three 627AUs for sale!

James

p.s. I got these from Lawrence already installed when I ordered the Zero. i believe they were around 30 bucks each at the time for those wondering how much they are to order.

[tinseljim]

Originally Posted by katanka

Now i need to try and get some grado 225's

Have you considered the MS1s? I just got a pair and they're lovely, also a bit cheaper. Still breaking in though so will let you know how I get on. But if you have your heart set on the 225s then cool! I have the 325s as well with the flat pads and think they go rather well with the 1364s.

jim

[kwekeugene]

I'm wondering what volume do you guys listen at? I have the Grado SR225, the volume is usually in the 9 o'clock for most songs, and probably 10 for a few songs.

What bout you guys? Just making sure I'm not listening too loud....

[tinseljim]

9h30 with the 325s. Occasionallly 10 as well.

[Henmyr]

Originally Posted by kwekeugene

I'm wondering what volume do you guys listen at? I have the Grado SR225, the volume is usually in the 9 o'clock for most songs, and probably 10 for a few songs.

What bout you guys? Just making sure I'm not listening too loud....

hmm ouch. I have OPA627 + LT1469 (EDIT: I used LT1469 not LT1364) now and am using my MS2i. They are probably rather equal to SR225 in the volume regard.

I'm around 8' and listening to "Nightwish - Wanderlust". I would even like to be able to go a bit lower, but then the channel imbalance kicks in. 9' is waaay to loud for my ears.

I tested the volume with my volume level meter, I use C-weighting, fast response and I look at the peaks.

8'o clock: around 65dB
9'o clock: 90dB!!!!! WAAAAAAY to loud.
I don't even want to go louder with fear of damaging my ms2i.

To keep the ears healthy in this hobby, I would suggest that you re-adjust to the 70-75dB range. It will take a while. In the beginning you will think that 70-75dB is extremely low volume, but after some weeks you will start to adjust and will not find it to be too low.

EDIT:
Trying the volume test again with a rather low volume cd: "Dire Straits(Brothers in Arms) - So Far Away"

8'o clock: 57-58dB
9'o clock: 78dB. This is much much better than 90dB.
10'o clock: around 94dB.

This CD is one of the lowest volume wise in my collection, and not even now is it safe with 10'0 clock.

[Henmyr]

Originally Posted by tinseljim

9h30 with the 325s. Occasionallly 10 as well.

How strange. You both do 9-10'o clock. I wonder if you have zeros which are different than mine, but I doubt it.

EDIT: For me, the biggest weakness of the Zero is the inability to listen at low volumes (around 60dB) with sensitive headphones. With MS2i and AD2000, I raise the volume slowly until the channel imbalance is gone and keep it there. This is around 8'. I only have 7,5' to 8,2' of the volume dial to use, rather bad. The Headfive is much much better in this regard.

I would like to have 50dB to be the lowest on the dial.

EDIT2: The Little Dot MKIII is also much much better, as I can listen at lower volumes.

[ciphercomplete]

Whats the word on the discrete module? How big of a difference does it make?

[tinseljim]

Originally Posted by Henmyr

How strange. You both do 9-10'o clock. I wonder if you have zeros which are different than mine, but I doubt it.

EDIT: For me, the biggest weakness of the Zero is the inability to listen at low volumes (around 60dB) with sensitive headphones. With MS2i and AD2000, I raise the volume slowly until the channel imbalance is gone and keep it there. This is around 8'. I only have 7,5' to 8,2' of the volume dial to use, rather bad. The Headfive is much much better in this regard.

I would like to have 50dB to be the lowest on the dial.

EDIT2: The Little Dot MKIII is also much much better, as I can listen at lower volumes.

I've noticed that the signal coming in via Mac optical is quite hot and it seems too much sometimes. Not sure how to regulate that without using the volume in iTunes which i'm sure degrades ths sq.

also the signal outgoing from the pre-amp is quite hot. these are probably related. but does anyone know how to change the output from an iMac?