[AmarokCZ]

ZERO has one LINE OUT, but it is switchable between: (1) fixed output; and (2) regulated output (regulation via volume control on front panel).

 

[cybertron]

Quote:

ZERO has one LINE OUT, but it is switchable between: (1) fixed output; and (2) regulated output (regulation via volume control on front panel).

Isnt the front panel output amped? My speakers are powered, and so I'm thinking an amped source would be bad, no?

 

[AmarokCZ]

Yes, the regulated LINE OUT is amped the same way as headphone out.

 

[cybertron]

Quote:

Yes, the regulated LINE OUT is amped the same way as headphone out.

 
Ah ok, both are amped. Can you help me understand this then... If I am trying to get the audio out to my M^3 amp, should you not amp the music twice? as you should not DAC the music twice either?
 
Maybe I just need a different DAC w/ volume control and no amp. Thoughts?

 

[AmarokCZ]

Not sure if we understand each other. Fixed LINE isn't amped. Regulated LINE is amped.
 
M3 has volume control so you can just use ZERO switched on fixed output LINE as DAC without volume control. ...or no?

 

[cybertron]

Quote:

Not sure if we understand each other. Fixed LINE isn't amped. Regulated LINE is amped.
 
M3 has volume control so you can just use ZERO switched on fixed output LINE as DAC without volume control. ...or no?

 
Sorry, I thought you said lineout was Amped as well. Ok, so Lineout to M3 will work great. How about to my powered speakers which have 3.5 mini and RCA input? Can I run them off the amped side (1/4 output) or is it going to sound bad?

 

[AmarokCZ]

Well I said that because it's true in some cases: LINE OUT can be either amped or not. You can switch between these two modes using one button on front panel. So you can connect M3 to RCA LINE OUT (asd preffereably use fixed - unamped - output) and also connect speakers to either 1/4 jack or RCA LINE OUT (you have to disconnect M3 since the amped and unamped LINE OUT uses the same RCA connectors) while using amped RCA output or 1/4 jack output.

 

[Lefoobar]

Just got this amp. I really like it, but it gets quite hot. Not too hot to touch but pretty warm. Any idea what would be a safe operating temperature or any guidelines to keep this thing from being damaged? 

 

[AmarokCZ]

The hottest place should be near the vents on the right side of the case. My normal temperature is ~15°C above the room temperature.
Once I had another ZERO that was very hot becuse of the transformer. But it was the old ZERO (see first post).

 

[petertz]

Hi,

 

[petertz]

  Yes, the regulated LINE OUT is amped the same way as headphone out.

Hi, Are you sure that? Do you have some ZERODAC schematics proving that? I think it's only attenuated via the same pot, switchable by relays. 
Thank You!

 

[AmarokCZ]

I have schematic so I'm 100% sure. The signal path of regulated LINE OUT is following: DAC => headphone amp => headphone jack (it serves as switch: when there are no headphones plugged the output is wsitched towards line out connectors) => serial resistors (10k) => RCA connectors. Second "proof" is that there are 3 cables connected to headphone amp: line in, power and line out. And third proof: when you play 50Hz sine and connect multimeter to LINE OUT you will measure approx 2V, if you switch to regulated and turn volume to max you will measure ~ 8V => it's not attenuated by POT, but amped (by headphone amp).
So from that you can see that regulated LINE OUT is degraded by additional amping by headphone amp and it also has huge output impedance.

 

[petertz]

Ok. Thank You. You convinced me of that. But that's too bad for the signal adding second amp in the path even better headphone amplifier as modding. It would be nice if the pot is only attenuator. Who needs 8v rms?

 

[AmarokCZ]

Since typical amplifier (stand-alone) has input impedance of 10kohm the output will be "only" 4Vrms. 

Yes it's bad for signal, but it's like having preamplifier which is quite common and not supposed to be bad...

 

[petertz]

  Since typical amplifier (stand-alone) has input impedance of 10kohm the output will be "only" 4Vrms. 

Yes it's bad for signal, but it's like having preamplifier which is quite common and not supposed to be bad...

 
>>Since typical amplifier (stand-alone) has input impedance of 10kohm the output will be "only" 4Vrms. 

>>>
Would You explain this in detail. I thought that 2Vrms input is quite enough for every power amp even with 10kohm input impedance. I couldn't made sence with this.
Thanks