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View Full Version : Suggestion: Volumen control bigger dB span



finnbrodersen
2008-11-03, 12:04
Hi

Running SBR (firmware 48), SBC (7.2 r3191), SC (7.2.1 r?)


Would like the lowest volumen to be lower, the jump
from "0=mute" to "1=lowest volumen setting" is to big for
my taste.

I do not know the dB span of the volumen control now.
Would like an increse the volumen span to some more dB.

The problem: I'm playing with my amp turned up high, to
be able to play loud, but then playing low is not possible
due to the volumen span of the SBR.

ps I use the analog output from the SBR


Finn
Denmark

Landhoff
2008-12-10, 06:03
Hi
I have exactly the same experiense - hence problem with my SB3 Classic. I bought a second hand Mission Cyrus XPA to drive my speakers with the feed from the SB's anlogue output. This move was to keep it simple and get rid of my NAD surround receiver with a number of analoque "ports" I basically don't need. So, big was my surprise and regret to discover that playing low-volume music is not an option...?!??? :o(

Regardless of the (appearently) many volume-steps on the SB it seems to start the first step at what I would asume is about 15% of fuld volume. From there the volume control seems to be reasonable linear.
That is not usefull - since it is impossible to play low back ground music!

Anybody (Slim Devices people!!!) any suggestions for a solution or comments for that matter...that does not imply additional equipment like e.g. a pre-amp. That undermines the fact that the SB is equipped with volume control.

Btw changing the nice name and logo of "Slim Devices" was IMHO a biiig mistake. I found a very nice second hand SB3 with the new remote and the old logo and name...me like! ;o)


/Landhoff

peterw
2008-12-10, 09:09
See this thread: http://forums.slimdevices.com/showthread.php?t=55863

Volume is set by Squeezecenter, and you can change the range by editing Slim/Player/Squeezebox2.pm (if you're running the .PL version as on Mac/Linux, rather than the Windows .EXE). The current range is ~50 dB, and it looks like you can go to about 80 dB and still have differences between each volume step -- below ~-80 dB you hit player firmware limitations with regard to precise gain control.

The Boom source code is a good read if you really want to do this -- it uses a dual-slope volume curve to provide a broad range while retaining a large number of steps in the "normal" volume range.

DaveWr
2008-12-10, 10:22
Hi,

Just to let you know if you start using very low volume levels on the analogue out of SB then it won't be very hifi. The volume is reduced by shifting bits in the digital domain. Whilst the SB3 has a 24 bit DAC - it should be OK til you get to 16 bits left, volumes lower than that will be throwing data away. The further reduction the more lost data. For HiFi there is no easy replacement for analogue volume fed by full range signal.

Dave

Mnyb
2008-12-10, 22:15
Most elegant solution is to use analog attenuators before the amp.

Then you can use most of the volume range in the SB and get lower noise floor to.

A resonable level of attentuation is so that full volume on the SB is as loud as you reasonable want to go (just a tad under clipping the power amp ;) )

http://wiki.slimdevices.com/index.php/Connect_To_PowerAmp

Personally i use Rothwell -10dB attenuators in my HT to level out differences between amps and use the full output of HT preamp (who also employs 24bit digital volume)

mooblie
2008-12-11, 05:25
Make sure you're using SC 7.3 - it has a different volume characteristic from SC 7.2.1 - with finer steps at the lower end for the analogue output from SB2/3.

finnbrodersen
2008-12-11, 07:14
Make sure you're using SC 7.3 - it has a different volume characteristic from SC 7.2.1 - with finer steps at the lower end for the analogue output from SB2/3.

Hi

Thanks for answers, I use Duet 7.2.1 on Windows.

I will wait for SC 7.3.x (when it is released) before "complaining" again

But I have the problem due to amp turned up high (about 1 o'clock)

Landhoff
2008-12-17, 07:58
Hmm - this is above my knowldge i'm afraid. For instance I don't understand how the SC - i.e. 7.3 - can influence the characteristics of the physical interfaces on the feeder (my SB3) and the power amp?!

As said I'm using the SB3 together with a Mission Cyrus XPA power amp with the following data...
Input sensitivity (50W/8Ohm) 380 mV
Input impedance 10 KOhm

Can anyone please help calculate "x" for a set of Rothwell -xdB attenautors?

Many thanks... ;o)

Landhoff
2008-12-17, 08:39
I guess I was just en lighted by reading the info-text for the various settings in SC.
I run SC 7.2 - 2244 and in "Settings/Player/Sound/Sound level for pre-amp" (or something like that, my text is in Danish - not sure exactly how it is translated) you can actually specify an attenuation level in dB.
The info-text says that this is a secondary sound volume control only affecting the analogue output on the SB3.

Not sure how great this is in terms of wanting hi-fi sound, but it works. Anybody who has more experience with this and can tell about pros and cons?