Hybrid vs. Straight Tubes

Wattage still does relate to loudness, but you also get the same loudness with less power if you have more efficient speakers. The other issues is how an amp handles clipping (tubes do it well, SS not so good), and short dynamic output for handling transients - and you can't really tell that from wattage. Some 50 watt amps have tremendous dynamic power that is only needed for very short periods of time and can sound every bit as "loud" and a 200 watt amp that doesn't handle transient power delivery quite as well. I can tell you a Pass XA30.5 sounds like a lot more power than many other "30 watt" amps.

Have owned SS up until just a few days ago, when I had and took the opportunity to trade my Nuforce class D 160w mono's for a Cary Rocket 88R (30w triode/60 ultralinear). Despite the low power rating I notice no degradation in sound quality, even at fairly loud levels running in triode. I was afraid that my Usher 87db/8 ohm (dipping into 4 ohms) speakers wouldn't be a good match for tubes. The Cary is happily putting that notion to bed. Quite happy with the sound.

I'll add that I had 3 different tubed preamps in front of my SS amps over the time I owned them, none of the combinations have come close to the character of the tube amp/passive pre combo I'm running now. The magic IME lies in tubed amplification.

Mechans' comment re: "tube output stage is critical, period" is probably fair enough, overall. In the case of the RS6, it's even more applicable. Speakers which have a spike in impedence in the presence range (IIRC, the RS6 qualifies - as does the Merlin VSM, another speaker that "flatters" tube output stages) sound more dynamic and alive with the right tubed ouput stage. You might get a taste with tubed drivers and SS output, but you won't get the whole deal.

Good Luck.

Marty

It's Monday! and I was back at work after 3 weeks off. But the good news is... I did bring a sound level meter home (TES 1350A).

I measured the level in my sweet-spot at the volume levels described below. Each level was measured while listening to various pieces of music (Take 5 Dave Brubeck, and Pergolesi's Stabat Mater - "Quando corpus morietur"). The distance from the speaker to the sweet spot is 3m.

1 - Normal Listening (WAF 10)-> 55 to 65 peak to 70 dB
2 - My Optimal (WAF 6) -> 70 to 82 peaks to 86 dB
3 - Loudest setting "Nick Turn the music down!" (WAF 0) -> 80 to 88 peak at 96

I then took more measurements for the first two settings playing a 1kHz tone and measuring the level at 1m.

Level 1 - 75 dB
Level 2 - 90 dB

So to conclude, Tvad if I understand you correctly with 1wpc I would have just enough power to listen at my optimal level. But since I do not want to be driving my amp at full power constantly a 10wpc would be preferable. 30wpc would provide more power than required.

But the above conclusion is strictly considering the rated wattage and not the dynamic power (point raised by Pubul57). Is there anyway to determine an amps dynamic power from it's specs?