[vcoheda]

I have a Corda Aria. When listening to it through my CD player, an appropriate volume level is around 9-10. But when I hook it up to my computer via a USB port, to achieve the same level of sound, I need to put the volume up to around 12:00 (also note that the volume on everything on my computer is at its maximum). I was also just reading a review on the PS Audio GCHA and the reviewer noted the same thing. That when he used the amp via its USB port, the volume had to be placed noticeably higher.

I find this odd. Why does this happen?

 

[jdimitri]

Probably because the cd player has more volume (current, power, i don't know) compared to the DAC in the corda aria

 

[bowraboy]

I notice the same difference between the internal DAC & an external DAC.

 

[ilovesocks]

There are many reports that the Aria's DAC is "anemic." My harman/kardon CDP is louder than the Aria's DAC as well.

 

[vcoheda]

Quote:

Originally Posted by ilovesocks /img/forum/go_quote.gif There are many reports that the Aria's DAC is "anemic." My harman/kardon CDP is louder than the Aria's DAC as well.

Right. But my point is that this seems to extend beyond the Aria. The PS Audio GCHA does the same thing as well. It seems to be something common to amps that utilize a USB port -- i.e., that the voulme needs to be turned up on all amps when connected via USB.

My question is: what is it about using an amp via a USB port that requires this increase in volume?

 

[nelda]

Try to use different USB port.
I use the one that in my monitor. it has cleaner and stronger signal than the one in my computer.

 

[m_memmory]

My Aria has the same thing - whatever I plug into the RCA inputs is louder then the internal DAC. It never really bothers me as I'm currently using the internal DAC and it's only on 10 so there's plenty of power left to go louder if needs be.

Could be that it's common with all USB ports or maybe some are more powerful/cleaner then others. I wonder if this'll lead to discussions about which motherboards have the cleanest USB ports?

 

[noseallinit]

I find it right opposite when connecting me MicroStack to me iMac. I need to cut the volume back just a bit.

I also notice no difference in volume levels between optical and USB on me iMac's output to the MicroStack.

I prefer when I have more field play in volume adjustment as appose to just a slight turn in volume to achive maximum listening levels.

 

[ATAT]

everything to do with the dac chip used.. Im not too sure but I think the aria uses the PCM27** or 29** line and those arn't that loud, on the other hand, other dacs like the PCM1739 can be VERY loud (volume knob nearly at off)

 

[vcoheda]

Quote:

Originally Posted by ATAT /img/forum/go_quote.gif everything to do with the dac chip used.. Im not too sure but I think the aria uses the PCM27** or 29** line and those arn't that loud, on the other hand, other dacs like the PCM1739 can be VERY loud (volume knob nearly at off)

I don't understand. Is the DAC chip then bypassed or disabled when the amp is hooked up through RCAs. If not, then that still doesn't explain why the volume would be louder via RCA and lower via USB.

 

[hugz]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif I don't understand. Is the DAC chip then bypassed or disabled when the amp is hooked up through RCAs. If not, then that still doesn't explain why the volume would be louder via RCA and lower via USB.

If using RCAs it wont be using an internal DAC

RCAs carry analogue signal. DACs convert digital signal into analogue. Since the RCAs are already carrying analogue there's no use for the DAC

 

[vcoheda]

Quote:

Originally Posted by hugz /img/forum/go_quote.gif If using RCAs it wont be using an internal DAC RCAs carry analogue signal. DACs convert digital signal into analogue. Since the RCAs are already carrying analogue there's no use for the DAC

This makes no sense.

All modern audio signals are in digital form (MP3s and CDs) and must be converted into an analog signal via a DAC.

 

[apostate]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif This makes no sense. All modern audio signals are in digital form (MP3s and CDs) and must be converted into an analog signal via a DAC.

You are correct in that there must be a DAC somewhere in the audio chain for a digital source (be it CD, mp3, etc.). The distinction here is that if you're using analog out from the source into the Aria your source is taking care of the D/A conversion and passing analog to the Aria which bypasses the Aria's DAC (since it's already analog). If you use USB, your computer is providing digital and the Aria's DAC coverts it to analog for the amp section.

Ant

 

[vcoheda]

Quote:

Originally Posted by apostate /img/forum/go_quote.gif You are correct in that there must be a DAC somewhere in the audio chain for a digital source (be it CD, mp3, etc.). The distinction here is that if you're using analog out from the source into the Aria your source is taking care of the D/A conversion and passing analog to the Aria which bypasses the Aria's DAC (since it's already analog). If you use USB, your computer is providing digital and the Aria's DAC coverts it to analog for the amp section.

That was helpful. So it must be the internal DAC of the Aria (or GCHA) that causes the attenuation of sound.