Computer volume at 100% connected to preamp = too loud ?!

[davewantsmoore]

Hi everyone. First poster here.

 

I have just bought a seperate DAC, pre and power amp... and they sound wonderful. The DAC is a MHDT Paradisea3, connected via my motherboards coax (and/or optical) SPDIF header.

 

I am using XBMC on Linux, and I have my volume on the computer set to 100% ... and I have been lead to believe that not setting it to 100% will degrade the quality of the output.

 

 

My problem is that when set this way, I reach max-blastage volume when the volume dial on my preamp is at 11 oclock (dial starts at 7)

 

This means I have vastly reduced volume-knob range, and potential for "damaging output".

 

Is this a common problem? Is there anything I can do other than turn the volume down a bit on the PC? Will that really ruin the quality?

 

Thanks in advance,

Dave.

 

[PeterSt]

Hi Dave,

 

Actually, nothing should be (hence can be) wrong with your setup. I guess it is the DAC's output voltage which is more than you are used to, that gets you this way louder sound.

 

In order to be definitely sure you should connect the DAC to the digital output of a DVD player, or possibly CD player you might have. But if I am right, there will be no difference.

 

The only thing to do in a legit way is just turning down the volume knob of your peamp. This isn't a real bad thing, although it won't be as comfortable as with more headroom.

 

If it really is outrageous, the DAC is to blame.

If you are using XLR-out from the DAC (if possible at all), using RCA may decrease the output with 6dB.

In either case I'd contact the manufacturer and ask him what the output should be according to their specs. If the answer is 2VRMS it should be allright theoretically, but maybe something is wrong.

Next you should find out what the output voltage is from the DAC etc. you were used to. If that is, say, 400mV, *that* one was wrong, and you are just not used to the loud level. In that case you have way too much gain in your main amps (compared to the sensitivity of your speakers).

 

Hope this helps !

Peter

 

[4est]

If need be, some inline attenuators such as Rothwell. They are easy to make as well. Excessive gain is a common problem. Be sure to roll some tubes. I had a paradesea and found a lot of tubes to be microphonic and vast differences in sonics between them. FWIW, the best tube I found was a rebranded cheapie. The second best was a NOS RCA. I didn't care for the WE.

 

[Part-Time Audiophile]

I had/have a similar problem on my rack. I think it had to do with the gain stages adding up a to "a bit much". Not knowing what your pre and amp are, I'd suggest taking a look at that and at the voltage coming of your DAC. You might just have too much of a good thing going on, you-know-what-I-mean?

 

[davewantsmoore]

Thanks everyone.

 

The DAC is definitely not the problem. (It has a 2v output) ... and the system works fine using a SPDIF out of a CD player.

 

It's the PC that's the problem.

 

I'm using XBMC on Linux, using the onboard coax SPDIF.

 

I';ve got all the volumes in ALSA and XBMC turned up to 100% ... IS it right to say that if I turn any of these down from 100% that I'll be sacrificing resolution.

 

 

The system sounds great, I just wish for a bit more range in the volume control.

 

Have thought about fixed attenuator in the signal path, but I'd really like not to add components that will affect the SQ if possible.

 

 

[weib]

imho lesser resolution less volume but more enjoyment > ear bleeding headache lol.

 

[4est]

I do not understand how you are getting more volume out of computer vs cd player as transport if you are using spdif from both.

 

You have too much gain, and there are only a few analog options. 2 volts is a lot for some pre amps. The amp I am using at the moment only requires .5 volt for full output. You are attenuating the signal either way, either with the volume pot or an inline voltage divider (Rothwell or home made as I recommended). I highly recommend you read the info on the Rothwell site, IIRC they explain it fairly well.

 

FWIW, and inline attenuator may increase your sound quality, not lessen it. I realize that may seem counter intuitive, but the pot will be more linear and S/N should decrease. Ultimately it would be best not to have too much gain in the first place, but that requires replacing something.