Kit installed, gain biased to R channel?


#1

Hi folks, just managed to get around to installing the kit today, no problems other than the issue with some of the screws on the back panel as discussed by some already.

Anyway, as I started to put the DS through its paces, my Tascam that’s connected to my amp lineout was showing more frequent overdrive on the right channel, something that I didn’t really notice before on the PWD. With my Mac connected via USB to the DS, I played some test sound files on the two channels, and using a very rudimentary measurement by looking at the peak of the VU meters on my Mac amp, there seemed to be an almost 10dB gain on the R over the L channel.

Using the balance control on the remote, I roughly equalized the channels by reducing the R by 15 units.

I’m on fw 6115, but had the same observations with 5407. Same results with different inputs, like USB and coax (CDP). If it matters, I’m connected to my amp using the balanced outputs.

Any ideas on what’s going on? Other people observed the same thing? Or is it just my kit?


#2

Actually, as I test this some more, I think it’s the reverse: that the R channel output is the correct level, while it’s the L channel that appears to be attenuated. Basically, I swapped between the output of my CD player, and compared it to the CDP->DAC output, and noticed the peaks on the R to be roughly the same, while the L when on CDP->DAC connection was lower than the CDP output.


#3
rocque said Hi folks, just managed to get around to installing the kit today, no problems other than the issue with some of the screws on the back panel as discussed by some already.

Anyway, as I started to put the DS through its paces, my Tascam that’s connected to my amp lineout was showing more frequent overdrive on the right channel, something that I didn’t really notice before on the PWD. With my Mac connected via USB to the DS, I played some test sound files on the two channels, and using a very rudimentary measurement by looking at the peak of the VU meters on my Mac amp, there seemed to be an almost 10dB gain on the R over the L channel.

Using the balance control on the remote, I roughly equalized the channels by reducing the R by 15 units.

I’m on fw 6115, but had the same observations with 5407. Same results with different inputs, like USB and coax (CDP). If it matters, I’m connected to my amp using the balanced outputs.

Any ideas on what’s going on? Other people observed the same thing? Or is it just my kit?


There’s a bug some uninitialized memory that gets used on software updates (like when you installed the DS kit, or sometimes even when you get newer software) In this case it’s the relative balance between the channels that’s got a garbage value.

With the remote control use the balance buttons (lower left corner, marked L and R) to even out the two numbers on the display. Then change the volume up and see if you are still balanced and then down and see if you are still balanced. If you aren’t repeat adjusting the balance and testing both louder and quieter to see if the balance stays centered. (You only have to go thru this rigmarole once, thank goodness)


#4

Thx Ted for the reply

I set the volume to 100, and the balance was at 100/100. If I change the volume, balance changes to the same (e.g. volume at 80, balance changes to 80/80). This seems to be correct (?).

Anyway, with volume and L/R balance at 100, that’s when I hear this imbalance. It’s only after I change the balance to 100/85 where things are about equalized.


#5
rocque said Thx Ted for the reply

I set the volume to 100, and the balance was at 100/100. If I change the volume, balance changes to the same (e.g. volume at 80, balance changes to 80/80). This seems to be correct (?).

Anyway, with volume and L/R balance at 100, that’s when I hear this imbalance. It’s only after I change the balance to 100/85 where things are about equalized.


That seems correct.

Does pressing the “phase” button on the remote twice change anything?


#6
rocque said Thx Ted for the reply

I set the volume to 100, and the balance was at 100/100. If I change the volume, balance changes to the same (e.g. volume at 80, balance changes to 80/80). This seems to be correct (?).

Anyway, with volume and L/R balance at 100, that’s when I hear this imbalance. It’s only after I change the balance to 100/85 where things are about equalized.


Also have you tried unconnecting the analog interconnects and reconnecting them? Just a stab in the dark.

#7
Ted Smith said
rocque said Thx Ted for the reply

I set the volume to 100, and the balance was at 100/100. If I change the volume, balance changes to the same (e.g. volume at 80, balance changes to 80/80). This seems to be correct (?).

Anyway, with volume and L/R balance at 100, that’s when I hear this imbalance. It’s only after I change the balance to 100/85 where things are about equalized.

Also have you tried unconnecting the analog interconnects and reconnecting them? Just a stab in the dark.


Thx Ted. Tried changing the phase, and reconnecting the XLR cables, no difference. I guess I should also try using single-ended RCA to see if that output makes any difference.

#8

It sounds to me like your “upgrade” did not totally flush the old memory of the display firmware.

I would try

1/ remove the sd card

2/ reboot the DS and see if any difference.

3/ if not, unplug the dac for 1/2 hour and reinstall 5407 [ original firmware].

4/ see if better,

5/ download a fresh 6115 from the web site, reformat the sd card to fat-16, load the fresh 6115 and insert the sd card back to the ds.

Reboot the ds to install the latest 6115.

I’m keeping my fingers crossed


#9

Thx Gordon for the suggestions

… ok, so I’m not sure what exactly happened, but magically everything’s working again. I was first swapping over to RCA (which had no issue), then I went back to XLR but swapped the channels, and things were okay?! I’m not going to speculate on what might have happened here, but I’m just happy things are good and I can enjoy the music!


#10
rocque said Thx Gordon for the suggestions

… ok, so I’m not sure what exactly happened, but magically everything’s working again. I was first swapping over to RCA (which had no issue), then I went back to XLR but swapped the channels, and things were okay?! I’m not going to speculate on what might have happened here, but I’m just happy things are good and I can enjoy the music!


Perhaps when you disconnected the XLRs as I asked you didn’t do both ends? I suspected a loose contact on one pin, but I didn’t know if it was at the DS or the preamp…

Anyway, I’m glad things are working.


#11

Clever hypothesis, Ted.

I bet you were correct.


#12

+1

And, one of the reasons I often suggest to “remove” all cables when attempting to reset the DAC. Removing at both ends, as Ted suggested, is an even better idea.


#13

Yeah, it’s weird, I did unplug both ends initially, and it didn’t change anything. However, after I swapped the cables over btwn L and R, it worked fine. (As a quick test to convince myself of my sanity, I swapped it back to the original configuration, and the problem came back.) So it seems like the cable termination is just not consistent on one of those cables, that pin contact on one or both ends played better in one config over another… anyway, I’m not going to bother trying to chase it down any further, everything is working as advertised and life is good!!

Thx all for your quick replies, this forum is fantastic!


#14

Odd.

Good to have the problem resolved for now, but I would track down the cause to make certain it is not a hardware issue. All one needs is another XLR cable from MonoPrice.