@microstrip
I am not sure where you get the specs on Burmester products and I unfortunately don't have the manuals handy, because I remember that the measurements for the 911 were very good to excellent.. (...) As for Signal to noise ratio anyone familiar with the 911 will tell you they are so silent as to make almost no noise even with high efficiency speakers : you put your ears to the speakers and there is NO noise ... and the rated signal ratio I remember from the 911 (on the earlier version of the manual circa 2003?) was quoted as 108 dB that is very healthy and I am not sure there are many tubes amps with these noise specs ...
Frantz,
Happy to confirm about your SNR findings. Real measurements from a review of the 909:
Rapport S/B à la puissance nominale : (full power)
109 dB lin - 117 dBA (pond)
- Rapport S/B pour 1 W en sortie : (1watt power)
85 dB lin - 93 dBA (pond)
I was wrongly referring to an old review that used non weighted values as weighted
But my tube Audio Research REF150 specs are :
HUM & NOISE: Less than 0.1mV RMS – 114dB below rated output (IHF weighted, input shorted)
You have to remember it has low noise JFETs at the input ...