I have often wondered this myself, especially with my very efficient
speakers (Zu Druids 101 Db). I think that the preamp section of an amp
should be at the unity gain setting for it's best performance. That is
the point where the preamp section is purely letting the signal pass
through, with no
dlite;193212 Wrote:
I think that the preamp section of an amp should be at the unity gain
setting for it's best performance. That is the point where the preamp
section is purely letting the signal pass through, with no gain or
attenuation being applied.
The problem is that at a 'unity gain'
As Ben Diss said, if you do this you will be amplifying the signal more.
That could result in slightly better signal/noise if it's the noise
floor of the amp that's currently the dominant contribution (to the
noise). It might also change the amount of distortion introduced by
the amp - it could
If your amp has a volume control, then (generally speaking) you should
not use the attenuation jumpers in the transporter, but use that volume
control instead. This will give you the best signal to noise.
--
bludragon
bludragon;192187 Wrote:
If your amp has a volume control, then (generally speaking) you should
not use the attenuation jumpers in the transporter, but use that volume
control instead. This will give you the best signal to noise.
Why do you say that?
The jumpers on the TP are analogue
opaqueice;192188 Wrote:
Why do you say that?
The jumpers on the TP are analogue attenuators, right? It's not at all
obvious that not using them will give the best S/N
Well, if not obvious then it is at least likely ... Noise introduced
by the amplifier after its gain control is of
ceejay;192191 Wrote:
Well, if not obvious then it is at least likely ... Noise introduced
by the amplifier after its gain control is of course irrelevant here -
it is whatever it is and nothing we do with the TP will change it.
Similarly, noise introduced in the TP *before* the attenuators
opaqueice;192266 Wrote:
Suppose for simplicity there are only two types of noise - noise before
amplification N_B, and after amplification, N_A. Then the total signal
going to the speakers is something like
g*(S + N_B) + N_A,
where g is the gain, and S the original signal. The final
All that formula shows is that more gain helps when noise is introduced
after the amp, but does nothing if it's introduced before.
But you're absolutely right - for the question at hand it makes more
sense to ask what happens when the output level is fixed. In that case
gain and attentuation
thanks for the great discussion so far!
but now I'm still pretty doubtful of making the change has any positve
effect.
surely I should try.
but you all know this needs time.
had some changes in the system the last few days, so I need more time
to suck in all the new good sound first, then
using transporter directly through my redgum amp (incl. pre-amp) into
BW N 802D.
very very nice.
always listening to music within the magical TP volume setting of -30
to 0 dB to maintain full bit depth (as far as I have understood).
but the amps volume control is only set to 1/3 of its full
I think you have it right the way it is. If you changed it you would be
attenuating the signal at the TP and amplifying it more at the amp.
-Ben
--
Ben Diss
'SB3' (http://www.slimdevices.com/pi_squeezebox.html) - 'Lavry DA10'
(http://www.lavryengineering.com/productspage_da_10.html) - 'BAT
truckfighters;192082 Wrote:
in other words: will the -6 dB transporter jumper change affect sound
quality in any negative way if I adjust my amp +6 dB higher to maintain
the same heard volume?
The only way to know for sure is to try it. As long as you're
comfortable that you know what
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