Does Replay Gain effect SQ?

[Ashmore]

That's it really. I gather digital volume control before the dac does, so does RG?

[Stratmangler]

I only use ReplayGain when I set my Squeezebox off on a random play, which is very rarely.
All of my library has been scanned for ReplayGain tags, specifically for such times.
Other than that I tend to set playback volume for each and every album, and as a consequence turn ReplayGain operation off.

[jandl100]

That's it really. I gather digital volume control before the dac does, so does RG?

I think there are 2 different processes at work here.

Gain is really just the volume (loudness) level. The same resolution of sound, just quieter or louder.

Whereas some digital volume controls actually reduce the resolution level as they are turned down. So the sound quality here is directly affected.

(EDIT: although if you are talking about SqueezeBox, then I don't know if anything special is meant by RG!)

[WAD62]

That's it really. I gather digital volume control before the dac does, so does RG?

Until recently I'd have said no, however I've changed my view since I got my M-Dac

I used to use RG (smartgain) on all of my SBs (4 in total), when I connected the M-Dac up to my SB receiver with RG turned on it was noticeable that the signal being received by the M-Dac varied between 17/44.1 to 24/44.1 (actual rather than nominal), dependant on track...still can't work out why the variation :doh:

Using crossfade also produced a similar effect, so some form of re-sampling/transcoding of the original 16/44.1 source is occurring. With them switched off the display shows 16/44.1, and is effectively bit perfect. For some reason the M-Dac is then able to utilise the original unaltered source better, various 'correction' and 'de-jitter' functionality is activated, and it does indeed sound better.

So it may be something that the M-Dac in particular exaggerates, or perhaps highlights...but I've kept RG and crossfade off on the source into my downstairs SBs, whereas I keep it on for my b'room system as I use playlists (ambient) there... :)

[lurcher]

That's it really. I gather digital volume control before the dac does, so does RG?

I dont think RG works in any different way than altering the gain/volume (makes no practical difference which word you use in this case) that the DAC is working at. So if altering the DAC volume (ie not using a analog pot after its in the analog world) does, then so does RG.

[sq225917]

RG just scans the track for peak level then applies gain to match all the files to a pre-set maximum level, probably a touch below 0.0db. The file is up-sampled to give the volume control extra bits to use so that there's minimal/no less of resolution as a result of the convolution.

I don't know why it doesn't constantly show the same sample rate and word length. But whatever the Mdac shows is exactly what it is receiving.

[StanleyB]

There are two types of digital volume controls. One involves adjusting the digital audio data.
The other one adjusts the gain of a VCA (Voltage Controlled Amplifier). The gain is adjusted in digital steps, but does not affect the digital audio data. It only affects the analogue audio.

[Vincent Kars]

ReplayGain or volume leveling is a tag in your audio file containing a number e.g. .65
If you activate ReplayGain in your media player it will multiply the samples with this value.
In essence it is the same as using the digital volume control of your media player

[sq225917]

Simon, short answer, a 24 bit volume convolution should have no/negligible audible effect as long as you aren't trying to use it to decrease the volume to next to nothing.

[Ashmore]

Thank you all. So I think what most of you are telling me is that using Replay Gain is just same as using a digital volume and will negatively affect SQ.

I shall have to do some listening tests - see whether I can detect it (and try not to be fooled by music that is simply louder!).

Cheers