[misterharrison]

Hi all

Just a quick question.
My RME soundcard has a choice in its output settings between -10dBV ("consumer" level) and +4dBu ("broadcast" or pro level).
The manual has the following table in it:

Reference          0 dBFS @           Headroom
+4 dBu              +13 dBu              9 dB
-10 dBV             +2 dBV               12 dB

Which would be more suitable if I'm connecting it up directly to the 2BSST's XLR inputs with balanced cables?

Many thanks

[brucek]

Since the 2BSST appears to have a 29dB voltage gain setting such that 1 volt will produce 100 watts, I would use the -10dBV setting on the sound card. It has a 0dBFS of 2dBV (1.26vRMS), so that is lots to drive the 29dB sensitivity setting on the power amp. The -10dBV setting will offer a lower noise floor from the sound card.

brucek

[misterharrison]

The -10dBV setting will offer a lower noise floor from the sound card.

Are you sure about that? It seems to me it would be the other way round, especially seeing as +4dBu is more commonly used in studio situations?

[brucek]

It's been my experience that when a soundcard offer the two levels of output, that the -10dbV setting will offer a better no-signal noise floor. Since the amp offers the ability to accept that setting I would try it and see if it is quieter when no signal is present.

Easy enough to test the higher output setting on the soundcard with the lower gain setting on the amp. The 13dBu (3.36vRMS) output is more than enough to drive it to full power, but you may notice a higher noise floor.

brucek

[misterharrison]

Thanks Bruce
So I won't damage the Bryston by putting a +4dBu signal into it?
If so, then I'll try both and see which one seems quiter, noise-wise.
I guess it's a choice between more gain from the soundcard and less from the Bryston, or less gain from the soundcard and more from the Bryston.

[brucek]

No, you won't damage anything by using the +4dBu setting.

If you used that setting with the Bryston set to 29dB voltage gain you would find the amp clipping with very little volume from the soundcard. It would be an inefficient 'gain structure', so when using the higher output setting on the soundcard you would use the lower sensitivity setting on the amp.

The +4dBu setting would offer a higher dynamic range, but only if it noise floor was consistent with the -10dBV setting, and I suspect it wouldn't be. Give it a try though, and see what sounds best with regards to noise and dynamic range.

brucek