Volume setting for Naim pre-amplifier


#1

Hi guys,

First let me apologize if this info. is already somewhere (a link would be awesome) but I’m having a problem with the output setting on my DS.

It seems my Naim amps expect 2.1Vrms at its input. Apparently my DS does 1.41 or 2.82Vrms (through rca outputs on the low and hi settings respectively). So I’m assuming I should set it to “high” but what level (out of 100) should I set it to? Can I assume 2.1/2.82 * 100 = 74.468 = setting of 74?

Am I missing something? Thank you for all your help in advance :slight_smile:

C


#2

Hi, I believe the voltages you quoted are incorrect. See the Stereophile review measurements:

“The maximum output voltage at 1kHz was 2.85V balanced and 1.44V unbalanced. Switching in the output attenuator with the touchscreen reduced these levels by just over 20dB, to 273 and 106mV, respectively.”

http://www.stereophile.com/content/ps-audio-perfectwave-directstream-da-processor-measurements

So, I would put the DS output setting on high and crank it to 100.


#3
Bootzilla said Hi, I believe the voltages you quoted are incorrect. See the Stereophile review measurements:

“The maximum output voltage at 1kHz was 2.85V balanced and 1.44V unbalanced. Switching in the output attenuator with the touchscreen reduced these levels by just over 20dB, to 273 and 106mV, respectively.”

http://www.stereophile.com/content/ps-audio-perfectwave-directstream-da-processor-measurements

So, I would put the DS output setting on high and crank it to 100.


Hi Bootzilla,

I’m quoting this: https://www.dropbox.com/s/3yigk2revwu17v4/DS%20specs.png?dl=0

It’s a shot from the PS website saying:

Output level, low 1.41 Vrms(+5BV)/3.15

Output level high, maximum 2.81 Vrms (+8dBV)/5.3 Vrms (+12dBV)

My point is that I’m not entirely concerned wit the whole dB values, just would like a suitable level I can set things to.

Currently the “low” setting sounds worse than the “high” but when I have it on “high” at 100, I’m barely operating the volume knob at all…


#4

I don’t know when the web site got corrupted, it used to be correct. The Stereophile numbers are correct.

Anyway each tick of the volume control is 1/2 dB. So using the RCA output of the DS at volume setting 100 won’t overload your amp. If your amp doesn’t then have the output volume range you need and it’s balanced input sensitivity is the same as it’s unbalanced input sensitivity you can consider using the balanced outputs of the DS and not going over a volume setting of 94 (20*log(2.85/2.1) is 2.65 dB which is about 5 or 6 ticks.)

You may have the opposite problem: if you always find that you are using a DS volume setting below, say 66, you might want to use the 20 dB attenuator in the DS and then use the volume set closer to 100. Your choice depending on which you like better.


#5
Ted Smith said I don't know when the web site got corrupted, it used to be correct. The Stereophile numbers are correct.

Anyway each tick of the volume control is 1/2 dB. So using the RCA output of the DS at volume setting 100 won’t overload your amp. If your amp doesn’t then have the output volume range you need and it’s balanced input sensitivity is the same as it’s unbalanced input sensitivity you can consider using the balanced outputs of the DS and not going over a volume setting of 94 (20*log(2.85/2.1) is 2.65 dB which is about 5 or 6 ticks.)

You may have the opposite problem: if you always find that you are using a DS volume setting below, say 66, you might want to use the 20 dB attenuator in the DS and then use the volume set closer to 100. Your choice depending on which you like better.

Thank you Ted - my amp is by Naim Audio and has only unbalanced inputs so from your post, I think I should set the DS to "high" and turn to full?

If this means anything, the pre amp’s “input sensitivities” is 75mV at 47kOhms with a 40dB overload margin. Its output is 0.775V at <50kOhms. The power amp’s voltage gain is +29dB.

Thank you so much, everyone. Totally appreciate your time.

btw. my figure of 2.1Vrms is with reference to the sources Naim make which output 2.1-2.2Vrms so I figure they’d referenced their amps to that sort of level.