[Trogdor]

The size of the unit is quite nice, really compact and can easily be placed on one's desktop. Also, notice the two blue LED lights. The blue LED on the left is for power, the right is for USB connectivity (always on even if you are not using the USB input but connected).

The craftmanship of the unit itself is very impressive for $400 USD. Its got some weight (official 2.2kg/4.8lbs.) to it which is quite surprising considering its size. Also the volume knob is quite cool, large and very easy to adjust for completely control.

Okay, so after listening to it for about 3 hours we have run into a major problem. Through the USB using DirectSound, everything sounds normal and generally pretty good. However, through the analog inputs from either my SCD-1 or Apogee, there is a distinct hum that we pick up on the Qualia's. What's worse is that on some tracks (e.g. No Doubt's "Hella Good") there is a noticeable dip when Gwen's voice moves from the left and rigth channels - its really really bad and seems to only happen through the analog inputs. We tried this with and without crossfeed but the problem remains.

Has anyone else experienced this issue? I've advised my buddy to contact Meier about it regardless but I just want take a quick poll. We are not sure if the hum is natural and the dip is just the way it is or there is something funky going on through the analog inputs. He was one of the first to order so it wouldn't shock me terribly if there are some glitches in the first production run (I'm quite aware Meier makes some high-quality products).

 

[EdipisReks]

the hum may be a ground loop, try a cheater plug somewhere.

 

[Trogdor]

Just want to state the hum is only through analog inputs, NOT through the USB input.

 

[Tim D]

Make sure the usb connection is entirely disconnected when using analog inputs, otherwise you are just asking for ground loop.

 

[Trogdor]

I tried that initially when the problem occured with the same hum being the outcome.

 

[gsferrari]

Try moving the amplifier to another room and see if you have the same problems.

If the problems disappear then try to move it further away from the laptop.

Just a suggestion...

 

[Tim D]

So you are getting a hum in the simplest case scenario with just a CD player source connected *only* to the Aria...and nothing but the IC inbetween the two and the associated power cords? Does the hum go up and down with amp volume adjustment?

 

[JaZZ]

Is there a hum without a cable/source attached?
.

 

[LFF]

Quote:

Originally Posted by EdipisReks the hum may be a ground loop, try a cheater plug somewhere.

Pardon the ignorance but what is a cheater plug?

 

[Trogdor]

Okay, so the hum occurs when the USB input and analog inputs are connected (even if we switch off the USB). That kinda sucks royally and I'm not sure if that's just my buddy's unit (i.e. my Apogee doesn't exhibit this issue with both connected).

Regardless, there is a massive dip in the music with just using the analog inputs. Again, its FLAC->Foobar->Apogee or SCD-1->Aria->Qualia. Its very noticeable on a lot of tracks. However, this dip goes away if you JUST use the USB connection so I'm thinking its an issue with the unit's analog input stage.

Does anyone else have this problem? Btw, we found this discreptancy because we were doing a side-by-side comparo of the Apogee against the Aria. Since the Apogee's DAC is going to be more accurate than the Aria's, we figured it would be more fair to just test the amp's output against the Apogee's headphone output (but using the same DAC). We expected the Aria to improve substantially but instead experienced this weird dip in the music!

 

[EdipisReks]

Quote:

Originally Posted by LFF Pardon the ignorance but what is a cheater plug?

 

[Tim D]

There wouldn't be any reason for the Apogee to exhibit ground loop even with usb connected because its a DAC and not an amp. It doesn't have analog inputs, and I wouldn't think connecting something to its analog out would affect what comes out of its headphone jack. I am guessing perhaps the usb switch may route which input source the Aria uses, but doesn't completely break the usb connection (i.e. if you flip the USB switch do you lose the usb audio device entirely from your OS?).

Why compare an SCD-1 -> Aria to the Apogee? Just do Apogee vs Aria headphone jack out by connecting Apogee outputs to Aria with no usb connected to Aria?

You can test if crossfeed is off by listening to only one channel to see if you get any sound from the other channel (just to make sure your crossfeed is 100% out of picture).

 

[Trogdor]

Quote:

Originally Posted by Tim D There wouldn't be any reason for the Apogee to exhibit ground loop even with usb connected because its a DAC and not an amp. It doesn't have analog inputs, and I wouldn't think connecting something to its analog out would affect what comes out of its headphone jack.

Okay, good point, I forgot there are no analog inputs to the Apogee. Still, the hum with both connected kinda sucks. (I mean I could imagine using it with a computer and a CD player though you can make the argument that it doesn't really have two inputs with a dedicated switch so I maybe being alittle hyper critical here).

Quote:

Originally Posted by Tim D Why compare an SCD-1 -> Aria to the Apogee? Just do Apogee vs Aria headphone jack out by connecting Apogee outputs to Aria with no usb connected to Aria?

We did that several times. We tested the Apogee->Aria with no usb connected and still exhibited the dip in frequency response. Its very odd. It can really be heard when Gwen's voice travels back and forth between the left and right channel. Her voice sort of just dies and doesn't follow the correct path back and forth between the left and right channel - I'm not sure if its a channel imbalance or something else but its very weird and not right. Again, its gone when we disconnect the analog inputs and just use the USB connection (no Apogee).

I know its not the Apogee since all is well if we use its headphone output or through my Dynamignt (again no Aria involved). Only when we introduce the Aria's analog input stage, we hear massive dips in the music, i.e. some of the frequency response range is sort of faded or recessed heavily. I mean this could be a breakin issue but I've never experienced anything like this and the amount of recessed signal is quite large on some tracks.

Again, I realize this is a first production run and glitches do happen!

 

[Tim D]

I could be wrong, but I don't imagine that there would be a lot of difference between the path from the built in USB DAC to Aria Amp vs analog input to Aria Amp to create such a difference such that I'd double check your IC's as well as making sure L is L and R is R, etc (maybe they got the channels wrong). I mean the actual amp section is the same behind either the USB DAC or analog inputs. Although actually I guess somehow the analog input could possibly get wired out of phase somehow (most previous Corda amps however didn't even have wiring and were just PCB mounted)

 

[Trogdor]

Quote:

Originally Posted by Tim D I could be wrong, but I don't imagine that there would be a lot of difference between the path from the built in USB DAC to Aria Amp vs analog input to Aria Amp to create such a difference such that I'd double check your IC's as well as making sure L is L and R is R, etc. I mean the actual amp section is the same behind either the USB DAC or analog inputs...

That maybe but there is a HUGE difference between the two. We tried two sets of cables and reversing the sides for S&G's with the same effect. My suspicion is that there is something wrong from the analog input stage causing the discreptancy (again I think this because like you I think there isn't much difference between the USB DAC and analog inputs to the amp output stage).