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

[edguetzow]

Originally Posted by Penchum

Good. I just wanted to make sure. The only other thing you could check is to look closely at every chip's top surface for a tell-tale sign of head damage, usually a circle spot that has turned to liquid and cooled. Then I guess look closely at the fuses, and connections. Let me know if you find anything suspicious.

Ditto. Also look at the cylinder like components on the board (capacitors?). There are quite a few in different colors and sizes. Look at the tops of each - usually silver with what looks like a faint "cross" or "X" etched in the top. Look for any that look "popped" or bubbling upward or out.

Get us more photos of the top of the board if you can, too!!

Going out for bit, check with you later!

[Penchum]

I'd really like it to be a fuse. That would make my day.

[Fremen]

Compared to the zero photos of Davve, I don't have this cap and resistors soldered down the board.. strange mod...
Anyway.
There are two relays on the board (2 yellow boxes), one is powered when there is a signal coming into the zero, and the other one when you push the preamp button (green light "phone" on).

Do you, Davve, can ear a "clic", showing that the relays are working?
- Zero on + signal to zero -> one clic
- push the preamp button -> one clic

If you have a voltmeter, you can check the -15V and +15V used for the opamps (on the main board connector of the three black wires going from the main board to the preamp board. the middle wire is 0V, the others are + and - 15V).
BTW, I had to trim the adjustable resistors (blue ones labeled pot_1 and pot_2) because the tensions where unbalanced when the zero came: +14.8V and -15V

[edguetzow]

Originally Posted by Fremen

Compared to the zero photos of Davve, I don't have this cap and resistors soldered down the board.. strange mod...
Anyway.
There are two relays on the board (2 yellow boxes), one is powered when there is a signal coming into the zero, and the other one when you push the preamp button (green light "phone" on).

Do you, Davve, can ear a "clic", showing that the relays are working?
- Zero on + signal to zero -> one clic
- push the preamp button -> one clic

If you have a voltmeter, you can check the -15V and +15V used for the opamps (on the main board connector of the three black wires going from the main board to the preamp board. the middle wire is 0V, the others are + and - 15V).
BTW, I had to trim the adjustable resistors (blue ones labeled pot_1 and pot_2) because the tensions where unbalanced when the zero came: +14.8V and -15V

Yes, I can see the difference in the photos. Somehow, davve's board has a cap and resistors soldered from the bottom while Fremen's does not. Davve's is different. Some sort of workaround at assembly? It may be a clue to his problem.

Time will tell!

[kmel]

Originally Posted by davve

Okey an update. I have accomplished to kill my Zero I hear no sound from the amp or the lineout, all leds are lightning.

Sorry to hear that... you wrote "all leds are lightning".

What about the LEDs on the front panel? Are they lit too? Always or only if you push the related button?

On the mail board:
The LEDs "reset" and "mute" are lit too? Not blinking if you push the related button?
What about the LED between the optical and coaxial connector? Does it lit only if you connect a source to the Zero?

[Henmyr]

Originally Posted by edguetzow

I had posted that my unit was doing this when I first got it. If you hook up an separate amp to the RCA outs, then push the "Preamp" button to light up the green "Phone" light - you then can control the volume going out to your separate amp.

Penchum, I had agreed with you when you indicated that I just keep the volume knob on the Zero at minimum (zero) and let the external separate amp do the volume control. This is what I have been doing all along and it works fine.

So, for me, it has always functioned in this manner. I now have the 1469 in the DAC with 2 LT1361's in the headphone amps.

Does your LT1469 get hot when you have it in the dac? Mine gets really hot so I dare not to use it that way, shame when it sounded rather good.

[davve]

Thanks to everyone! all being very helpful!

All leds lit on the front too.
When i power on the zero it clicks and if i push the preamp button it clicks.

[Seba]

I have some components under the main board too. Everything works ok.

[kmel]

Originally Posted by davve

All leds lit on the front too.

If the 4 front LEDs are lit simultaneously the microcontroller is not working well.
It initializes the input receiver and the DAC. Without that or with a wrong initialization it's possible that you can't hear anything.

What happens if you press "mute", does the LED blink?

[davve]

Originally Posted by kmel

If the 4 front LEDs are lit simultaneously the microcontroller is not working well.
It initializes the input receiver and the DAC. Without that or with a wrong initialization it's possible that you can't hear anything.

What happens if you press "mute", does the LED blink?

Ohh did'nt mean all, if i press coax the led lit and not the optical.

[Penchum]

Originally Posted by davve

Ohh did'nt mean all, if i press coax the led lit and not the optical.

Hey Davve, you did say your DV is ok, right? You have something to listen too in the mean time?

[davve]

Originally Posted by Penchum

Hey Davve, you did say your DV is ok, right? You have something to listen too in the mean time?

Yes i have it connected to my AP192. Have you seen my new pics on page 163?

[Penchum]

Originally Posted by davve

Yes i have it connected to my AP192. Have you seen my new pics on page 163?

Great! I would have hated it if you had nothing to listen too!

I've been looking over those nice new pics. The only thing I have noticed (and it may be nothing) is: In the second pic down, that big "Sync MOS" chip looks like it had something wrong with it. On the end of it closest to the camera, you can see where it looks like something has ran down from the pin layer of the chip (middle of the end), to underneath the chip. Like it spewed something out that end?

[davve]

Originally Posted by Penchum

Great! I would have hated it if you had nothing to listen too!

I've been looking over those nice new pics. The only thing I have noticed (and it may be nothing) is: In the second pic down, that big "Sync MOS" chip looks like it had something wrong with it. On the end of it closest to the camera, you can see where it looks like something has ran down from the pin layer of the chip (middle of the end), to underneath the chip. Like it spewed something out that end?

I took out the chip and had a closer look. It looked just fine!

[Penchum]

Originally Posted by davve

I took out the chip. It looked just fine!

Ok, good. Everything appears to be fine, as far as I can see from the pics. I don't see any obvious signs of a bad component. Great pics though! What are you going to do next? Just curious.
Thanks!