XDA-1 balanced connection problems

[tjhenry]

I've compared the XDA-1 balanced and unbalanced analog outputs and the UNBALANCED output is CLEARLY louder than the balanced out. Has anyone else experienced this? The balanced connection is supposed to be louder right? Something like 6 dB? I wonder if this may be a defect.

I have a single balanced input on my integrated amp and I've checked another balanced source I have into the amp and the other balanced source is louder as expected. So, the input doesn't seem to be defective.

Just wondering if other XDA-1 owners have noticed this.

Thanks

[ajani]

yep my RCA out is louder as well... It maybe due to this:

Fully Discrete Differential Reference™ Output Stage with fully independent balanced and unbalanced drive stages

Hopefully someone with more technical knowledge will explain it...

[geebo]

I notice on my Emo Ultra 12, the input sensitivity is .5v for balanced and 1v for unbalanced.
I wonder what that means in the scheme of things...

[roadrunner]

You need not be concerned about whether the balanced or unbalanced connectors have a different sound level. There is nothing inherent about the balanced connection should be 6 db louder. It is totally an arbitrary decision. Balanced are generally intended to be used on long cable runs and some vendors will boost the signal level to help compensate for that. Many vendor have elected not to follow the signal boost for balanced connections. This is not a defect and has no impact on the sound quality.

Just relax and enjoy your listening. The deviation you have noticed has no meaningful performance issues.

[Erwin.BE]

Dec 15, 2010 17:23:43 GMT -5 tjhenry said:

I've compared the XDA-1 balanced and unbalanced analog outputs and the UNBALANCED output is CLEARLY louder than the balanced out.

Oh no! You mean you have to set the volume to 1 (whole one) and not 0.5?

[tjhenry]

Thanks for the input roadrunner. In numerous descriptions of balanced connections, it always seemed as if the balanced circuit was supposed to be louder than unbalanced due to reduced noise, interference, etc. I thought the engineering of the circuit required it to be louder. I appreciate the information.

If I were using the XDA-1 as a pre-amp I would definitely use the balanced connection. Now it makes sense why Emotiva would release it with the gain structure it has. From what I've read, all previous demos of the XDA-1 were in conjunction with balanced connections to XPA-1s.

For XDA-1 owners using amps without balanced connections and with problems of too high volume on 0.5 for the XDA-1, I would suggest getting some XLR to RCA converter plugs and using the balanced out of the XDA-1. I didn't measure the difference in sound levels for balanced versus unbalanced, but it had to be somewhere in the 5 to 10 dB range. I tried the XDA-1 briefly as a preamp connected using unbalanced to a Rotel RB-1090 and 0.5 was too loud for background listening.

Thanks again for the help

[ajani]

Dec 15, 2010 19:29:16 GMT -5 tjhenry said:

Thanks for the input roadrunner. In numerous descriptions of balanced connections, it always seemed as if the balanced circuit was supposed to be louder than unbalanced due to reduced noise, interference, etc. I thought the engineering of the circuit required it to be louder. I appreciate the information.

If I were using the XDA-1 as a pre-amp I would definitely use the balanced connection. Now it makes sense why Emotiva would release it with the gain structure it has. From what I've read, all previous demos of the XDA-1 were in conjunction with balanced connections to XPA-1s.

For XDA-1 owners using amps without balanced connections and with problems of too high volume on 0.5 for the XDA-1, I would suggest getting some XLR to RCA converter plugs and using the balanced out of the XDA-1. I didn't measure the difference in sound levels for balanced versus unbalanced, but it had to be somewhere in the 5 to 10 dB range. I tried the XDA-1 briefly as a preamp connected using unbalanced to a Rotel RB-1090 and 0.5 was too loud for background listening.

Thanks again for the help

Nope still doesn't make any sense... I use it with XLR to my XPA-2 and the volume control is virtually useless... my speakers are 90db sensitivity (so just above average, but not high efficiency like horns)...

[ocean2059]

I've been using XLR connection with my XPA-2 and I have no problems with volume control. My speakers are B&W 805.

[rixtergonzo]

Dec 15, 2010 20:40:55 GMT -5 ocean2059 said:

I've been using XLR connection with my XPA-2 and I have no problems with volume control. My speakers are B&W 805.

As I have B&W 802Ns with XPA-1s and also have no volume control issue...B&Ws???

[sharkman]

Could ocean and Rixtergonzo please describe in more detail what they are experiencing with their volume? For instance, when at 0, if you turn the volume up to .5, do you hear anything? If the volume is operating correctly, you would probably hear next to nothing until past 5 or 6 on the volume level, and levels of 50 or 60 should be doable.

For the volume to be working correctly, you should get a .5 decibel increase only for every .5 increase of the volume.

[rockguitar]

Dec 15, 2010 19:29:16 GMT -5 tjhenry said:

Thanks for the input roadrunner. In numerous descriptions of balanced connections, it always seemed as if the balanced circuit was supposed to be louder than unbalanced due to reduced noise, interference, etc. I thought the engineering of the circuit required it to be louder. I appreciate the information.

If I were using the XDA-1 as a pre-amp I would definitely use the balanced connection. Now it makes sense why Emotiva would release it with the gain structure it has. From what I've read, all previous demos of the XDA-1 were in conjunction with balanced connections to XPA-1s.

For XDA-1 owners using amps without balanced connections and with problems of too high volume on 0.5 for the XDA-1, I would suggest getting some XLR to RCA converter plugs and using the balanced out of the XDA-1. I didn't measure the difference in sound levels for balanced versus unbalanced, but it had to be somewhere in the 5 to 10 dB range. I tried the XDA-1 briefly as a preamp connected using unbalanced to a Rotel RB-1090 and 0.5 was too loud for background listening.

Thanks again for the help

Actually, if you are hearing a 6db louder sound level with an RCA connection than with the balanced connections, that is the NORMAL design of many amps.

When I used to have the Pass Aleph 30, it had a gain of 20db balanced and 26db unbalanced (through the RCA). See the last page of the manual in the link for the published specs.

www.passlabs.com/pdfs/old%20product%20manuals/a30manr0.pdf

It would appear Emotiva has done something similar in the XPA-1 amplifier, the RCA inputs having more gain than the balanced inputs.

As I've posted in my measurements of the volume control in page 2 of this thread

emotivalounge.proboards.com/index.cgi?board=preampdac&action=display&thread=15010&page=2

The output voltage of the RCA outputs of the XDA is the same as the balanced XLR outputs.

This means if you use a direct connection between the XDA and XPA-1 amp, the increased loudness for the RCA inputs is typical, because of the amplifier design.

[rixtergonzo]

Dec 16, 2010 11:27:53 GMT -5 sharkman said:

Could ocean and Rixtergonzo please describe in more detail what they are experiencing with their volume? For instance, when at 0, if you turn the volume up to .5, do you hear anything? If the volume is operating correctly, you would probably hear next to nothing until past 5 or 6 on the volume level, and levels of 50 or 60 should be doable.

For the volume to be working correctly, you should get a .5 decibel increase only for every .5 increase of the volume.

Sorry...crossing threads:

emotivalounge.proboards.com/index.cgi?action=display&board=preampdac&thread=15059&page=5#237407

[sharkman]

Dec 16, 2010 11:51:09 GMT -5 rixtergonzo said:

Sorry...crossing threads:

emotivalounge.proboards.com/index.cgi?action=display&board=preampdac&thread=15059&page=5#237407

Rixter, your results are indeed puzzling, my measured db level at .5 on the volume is 60, and each .5 increase on the volume gives 6+ db, but it levels out so that by 6 or 7 I'm getting close to the advertised .5 gain for each .5 volume increase.

Funny about this gain problem...I have my XDA-1 used as a preamp connected directly to a pair of XPA-1s via EMO balanced interconnects to a pair of 91db B&W 802Ns and my unit seems to be functioning as advertised. I can rev up to 45-50 to get to my normal loud listening level. At 0.5 it is at a very low background level.

Is my XDA-1 something different than the rest or am I the only one running a pair of XPA-1s? Is it the B&Ws? Was the XDA-1 only designed and tested around the XPA-1s using balanced input? Maybe?

[ocean2059]

Dec 16, 2010 11:27:53 GMT -5 sharkman said:

Could ocean and Rixtergonzo please describe in more detail what they are experiencing with their volume? For instance, when at 0, if you turn the volume up to .5, do you hear anything? If the volume is operating correctly, you would probably hear next to nothing until past 5 or 6 on the volume level, and levels of 50 or 60 should be doable.

For the volume to be working correctly, you should get a .5 decibel increase only for every .5 increase of the volume.

In my setup, Oppo 93=>XDA-1=>XPA-2(via balanced cable)=>B&W 805, the volume range that I use is between 5 to 30 plus. Above, 40, it's becoming too loud (I listen mostly classic music). I do hear 0.5 db of increment of change.

Cheers,

[sharkman]

Here's a little update for those who may be interested. As some experienced a db decrease with XLR cables, I had ordered some and they came in today.(cheap Monoprice, no less!) My set up goes: ERC -coax- XDA - XLR - XPA-3, with one channel idle. I experienced no db difference between this and RCAs from the XDA to the XPA-3. So as some said, it may be specific to the XPA-1 amp only. Carry on.