Re: The Last Word

Brian Running <brunning@xxxxxxxxxxxxxxxxx> wrote in
news:cp69l.8410$hc1.3863@xxxxxxxxxxxxxxxxxxxx:

The BorgMan wrote:

What you and Aaron are arguing is this: Why not try to minimize the
amount of noise as much as possible?

Because you don't want to walk 8 feet back to your amp, around the
drum kit, to turn down the master volume on your amp to save a .5dB
reduction in SNR for that one quiet song.

Because you like the sound the loading of the tone pot and volume pot
give at a particular position.

Because you have a bass with an active preamp, and the SN level even
at extremely low volume settings is way beyond sufficient.

Because you have a bass with an active preamp which is noisier than
the front end preamp on your amplifier.

Because you have an active bass with a preamp that happens to have
increasing noise with increasing gain.

Because running your active bass preamp wide open forces the input
amp in your bass preamp to operate in a less linear region of gain.

There's no reason not to.
There's no cost involved in turning up your bass's volume control,
there's no cost involved in proper gain staging, these are just
ordinary, normal steps that any sound professional will take. How
on earth can you question this?

Sometimes there are costs - either in convenience, tone, or even
noise. Most of those costs are minimal, but in many situations that
minimal cost still outweighs the benefits.

...and proper gain staging doesn't always mean "Get the most signal
possible" out - it's the most CLEAN signal possible, and many
electronic circuits exhibit increased at gains both higher and lower
than unity.

And yet, even in the face of all of these suppositions, assumptions,
hypotheticals and rhetorical straw men, out in the real world it
actually works, and real, live professional sound engineers routinely
set up their gain staging to maximize S/N ratio.

Within reason, yes - although most guys I know who record to digital tend
to like their peaks hitting a good bit below 0dBFS, resolution and noise
floor are so good with modern converters you'd rather trade the decrease in
SNR for a decrease in the likelihood of clipping the ADC.

You're happy being
the lone voice in the wilderness, refuting reality and claiming that
basic gain-staging techniques are wrong or at least unnecessary --
well, I guess that's your role. Why not make a real statement to the
world -- run your bass with the volume pots just barely off zero, keep
your pre-amp gain just barely off zero, keep all your effects and
processor levels just barely off zero, and then make up all your gain
at the power amp stage. Tell yourself that all that noise you're
hearing can't be helped, because there are such tremendous costs
involved in avoiding it.

Honestly, I don't get you guys.

If your active bass has a preamp that's noisy above unity gain - should you
run the bass wide open and adjust your volume at the amplifier, or should
you run the bass volume at it's lowest noise point?

No one is saying there is no effect of turning down your volume - a larger
effect with a passive system - but the effect of turning your volume from
100% to 75% is probably going to be less than the effect of going from a
10' to a 20' instrument cable.

Want to maximize SNR? You need to balance gain vs. noise.

If your device is less noisy (or equally noisy) at higher gains - run it as
hot as you can into the next device without overloading.

If your device is noisier off unity gain, then you need to choose a gain
large enough to provide a good signal for the second stage without
increasing noise enough that it swamps the gains you achieve from the
signal level boost.

--
Aaron
.

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