Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 32 - Head-Fi: Covering Headphones, Earphones and Portable Audio

arteom · #**466** (**permalink**) 12-31-2007, 07:25 AM

hey penchum, Im about 50 hours into burn in. The bass goes lower, which is good. The highs have extended, but quite honestly the highs are really bright right now (I'm getting quite a bit of sibilance). I do hope this fixes itself.

Also to update on my situation with the Signal to noise ratio increasing after the unit was left on for a long period of time; I emailed Lawrence and he just reccomended I open up the unit to check for loose connections and make sure its in a well venitlated place. The connections seem to be in order. Do want to say that this happened only once, I have left the unit on for a bit afterwards for a day or so (and continue to leave it on) and haven't had the same thing happen.

Penchum · #**467** (**permalink**) 12-31-2007, 07:39 AM

Quote:

Originally Posted by arteom

hey penchum, Im about 50 hours into burn in. The bass goes lower, which is good. The highs have extended, but quite honestly the highs are really bright right now (I'm getting quite a bit of sibilance). I do hope this fixes itself.

Also to update on my situation with the Signal to noise ratio increasing after the unit was left on for a long period of time; I emailed Lawrence and he just reccomended I open up the unit to check for loose connections and make sure its in a well venitlated place. The connections seem to be in order. Do want to say that this happened only once, I have left the unit on for a bit afterwards for a day or so (and continue to leave it on) and haven't had the same thing happen.

Hey Arteom! Man, I though you'd crawled in a hole somewhere!

I'll be the first to say that "anomalies" usually don't occur with digital sources, but I have seen a few in the last few years. Not with the Zero, but with sources. I have a Yamaha CD player that will work excellent for days, then go completely stupid for 5 minutes! Very weird!! I'm glad things are going well, and I believe you'll find the highs settle down in the hours to come. So far, the consensus is still a 100hr burn-in, so hang in there and tell us at what point the highs settle in. See Ya!!

Krendopolis · #**468** (**permalink**) 12-31-2007, 08:26 AM

Quote:

I'm sure you could rig the headphone jacks output to another units input, but why would you want to do this?

Well someone did just say they are dissatisfied with the line-out sound relative to that from the headphone jack and it does have the gain control if your amp doesn't.

Quote:

If you think it is possible the protection circuits are kicking off the output, tell us exactly how you have it hooked up to what other equipment and maybe we can help somehow.

Nope tried different combinations just doesn't work. Lawrence has offered to take the dac back only to rework.

Penchum · #**469** (**permalink**) 12-31-2007, 08:52 AM

Quote:

Originally Posted by Krendopolis

Well someone did just say they are dissatisfied with the line-out sound relative to that from the headphone jack and it does have the gain control if your amp doesn't.

Nope tried different combinations just doesn't work. Lawrence has offered to take the dac back only to rework.

Ok, I see now. Well, I think I would send it back to Lawrence and let them fix it. Better to have it fixed permanently. Good luck!

nor_spoon · #**470** (**permalink**) 12-31-2007, 08:58 AM

Wating is pain...
Deciding on a thing right before christmas is just stupid! The postal service is sloooooooow

Penchum · #**471** (**permalink**) 12-31-2007, 12:14 PM

Quote:

Originally Posted by nor_spoon

Wating is pain...
Deciding on a thing right before christmas is just stupid! The postal service is sloooooooow

Where is yours at now? I'm going to check on mine...

davve · #**472** (**permalink**) 12-31-2007, 12:15 PM

what opamp do you recommend if you are gonna use it with a headphone amp?

Penchum · #**473** (**permalink**) 12-31-2007, 12:21 PM

OMG!! I checked on my Zero, it is still showing San Fransisco. I also checked on my LD MKV and it shows: Processed, December 30, 2007, 3:33 pm, PHOENIX, AZ 85026!! That means they may deliver the MKV today!! I am so totally in shock! I need a Valium.

Penchum · #**474** (**permalink**) 12-31-2007, 12:26 PM

Quote:

Originally Posted by Shopper

More ideas?

LT1364 in the DAC (or DY2000), and 4x OPA627 (on two adapters) in the headphone amp;

DY2000 in the DAC (or LT1364), and 4x LT1122 (again on two adapters) in the headphone amp.

The first idea sounds interesting, but expensive. The second, probably more practical.

If they ever find my lost 797's, I'll have enough to do 4x of them on two adapters in the headphone section! How wild would that be?

Penchum · #**475** (**permalink**) 12-31-2007, 12:53 PM

Quote:

Originally Posted by davve

what opamp do you recommend if you are gonna use it with a headphone amp?

It is really hard to say right now. I have been experimenting with different combinations. I don't have enough Opamps to check too many combinations, but right now, I have the single OPA627s on the adapter, in the DAC section and I took out the stock dual Opamps (5532s) in the headphone section and put in 2 dual LM4562s.

It is an interesting combination. When listening with headphones, I'm getting the super deep bass of the OPA627s and the full range and dynamics of the LM4562s without it being overly bright! Listening to my Super T amp from the Zero's pre-out, I'm getting all the warmth and full spectrum the OPA627s are known for. This is indeed a cool combination. I expect we will run into many more good combinations in the next few weeks. Shopper has a ton of Opamps coming, I have a few and several others have some coming. After their Zero's brake-in periods, the testing will go wide open and much will be posted about the results. I have 4 single OPA797s with two adapters coming and I also have 4 Dual LT1364s coming. Stay tuned!