Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 99

IMO the supply current is used even the opamp isn't amplify anything. I don't think that is the only cause of the high temperature.

I found following statement on physicsforums:
Let's take a look at the current output:

OPA2604: 35mA typ (standard Zero type)
LT1057: ???
LT1361: 34mA typ
LT1364: 60mA typ
LT1469: 22mA typ

If the Zero takes more than 22mA the LT1469 is running hot.

I seem to recall that the 1364 ran very hot also. At 60mA it should not have begun heating up as compared to the stock OPA2604.

Seemed like it was just as hot as the 1469 but I am judging strictly by touch.

I hit the wall right after the LME49720 test, and only heard the imperfections in the op-amps, the small colorations. I have taken a small break to get back on enjoying the music again as well as the zero. I will do the LT1469 test soon I think however. Have ordered two OPA627AP also to use as dac.

I'm using LT1469 in the dac now with LME49720 in the amp, and it is a good combination, as was LME49720(dac) + LT1469(amp).

Hi Henmyr,
i've just seen that you're using this unit as amp too, with a Beyer DT-990, a headphone i know pretty well.
Can you tell me how does it sounds, compared to the Meyer dedicated amp?
Thanks in advance

They are very similar. At first, when the zero was new, it was very clear and sharp, much more clear than H5, but now after burn-in it's more mellow than before, and approching the H5 more and more.

With LME49720 (same as LM4562) (dac) + LT1469 (amp) the tonality is also very similar to H5, although the zero is just slightly very slightly more clear.

I have a hard time comparing the two (especially with dt990, as they have a very significant signature), but I would say that they are about equals.

The soundstage might be slightly larger than the H5, depends on what Op-amps are in.

The H5 has a very natural sound and good timber, something which the zero is just slightly slightly very slightly worse than H5 (this might be corrected with the right op-amp combination).

Overall, I have a very hard time to declare a winner during my short test.

There might be a very good op-amp combination for zero with dt990 which puts it significantly ahead, but I haven't found that for dt990 yet (and maybe never will, as I'm getting closer and closer to selling them).

This was tested with the DT990. With dt880 and ms2i, I think (must listen more) that I prefer the zero.

I hope that the zero will clear up with more burn-in, because I liked the clear sound it had in the beginning very much. I'm hoping OPA627 will bring some air also.

Has anyone compared this Zero Dac w/ an Oritek modded Zhaolu? Thanks.

Hi Henmyr,
thanks a lot for your answer. So also the built-in amp is a little-killer one
I'm gonna buy a unit with OPA627 on DAC, but i'm really confused about which opamp for amp section, do you have any suggestion?
My phones are the Sony mdr-7506, that are a bit brilliant..
Thanks in advance

I wonder how many gullible people would be willing to pay additional $700 for such negligible mods compared to the original Zhaolu, it costs 7 times more

Get a life (and a Zero, of course...)

The op-amps in the amp are very dependent on the op-amp in the dac, so I can't know at this moment which op-amp will be best with OPA627 in the dac. I find the LT1469 and LME49720 (same as LM4652) to be the best overall so far for the amp with dt880/ms2i/dt990.

EDIT: Do not neglect the stock op-amp combination, as I find it to very enjoyable with every headphone.

How about just an unmodded Zhaolu?

Haven't been around very long,eh? The last time I checked Ori sent out a brand new modded unit for close to $450. Discrete output isn't what you'd call a "negligible" mod, like say swapping out an op-amp.

Hi Henmyr,
i've just e-mailed Lawrence to ask which one he recommend with the OPA627 in the dac..he suggest me another opa627 in the amp section..but i'm not sure i've understand well..another OPA627 in the amp?? Is it possible?
It's another interesting point of view
Just one more question: when you tested the Meier h5 vs the Zero internal amp, did you used the stock op-amps?