tube Watts vs solid state Watts

Not all ss amps clip harshly, if at all. My CarverPro ZR1600 have clip detection and automatic gain reduction if clipping occurs. I have never seen the CLIP LED illuminate. However, in home audio application this is probably the usual case as the darned thing is rated at 600 watts into 4 ohms.

Other than the tubes vs. solid-state argument and the class A vs. class B argument, an amp with a larger power supply will often sound louder and more dynamic due to its ability to drive more current, i.e. dynamic headroom. When I was in school I learned this and was amazed at a demo at my local Circuit City. The salesman there was comparing a 26 wpc Harmon Kardon receiver versus a 90 watt Pioneer integrated amp. I and others there expected the more powerful Pioneed to blow away the HK, right? So we were all amazed to hear not only that the HK had much better sonics, it played much louder. The sales guy then asked someone to stand on a scale he brought in and the HK was twice as heavy, hence a much bigger power supply.

I suspect that part of the perception that tube watts sound louder than solid state has to do with people being deceived into thinking they need WAY more power than they actually do need.

Solid state can deliver a lot of power cheaply. So, makers of a lot of solid state gear push the benefits/need for a lot of power. Power is much harder to supply from tubes, and personally, I find most high powered tube gear sounds pretty bad.

So, when one hears a demonstration where a tube amp sounds really good while being rated at 20 watts and a 200 watt solid state amp sounds less impressive, one tends to conclude that the 20 watts of tube power sounds stronger. Actually, it is more likely to be the case that the speakers really only need a few watts, when played at normal levels, so the extra power of the solid state amp was wasted. Oversized solid state amps are particularly cheated in such demonstrations because a lot of solid state gear does not sound its best when idling along while tube gear is at its best at low output.

I see so many people argue about how much power is needed to achieve "realistic" levels, based on measurement of SPL at concerts and factoring how much power is needed to achieve peak levels. But, the simple fact is that NO commercial recordings ever deliver that full dynamic range so one never needs what "theory" supposedly dictates. I'll take great performance over the first watt of power any day over ability to deliver a lot of power for peaks that may never actually be in a recording. One watt on most speakers, even inefficient ones, is surprisingly loud.

Ok folks, so the point is here not that the tube Watts are more "powerful" than solid state Watts in absolute terms (when measured) but they are more powerful in terms of psycho acoustics. It's the subjective finding that not all Watts are the same. So when someone is saying that a 20W tube amp is more powerful than a 100W solid state amplifier you have to correct that somewhat by using abovementioned explanation.

Chris

I took the trouble to actually measure the voltage being applied to my 4 ohm MG 1.6 speakers by my 600 watt amps during peak volume intervals of VERY loudly played music. I wanted to know if a lower powered amp would be OK. Most of the time the maximum rms voltage over a brief (1 second) interval was 10 volts or less, which correspionds to 25 watts. (At times when the music was quiet the voltage was only a couple of volts, which is one watt). However, there were a few moments when I saw about 40 volts and this would correspond to 400 watts. A 40 volt rms sine wave would have instantaneous voltage peaks of 56 volts. Since the CLIP LEDs did not illuminate I guess that my amp was able to follow a 56 volt peak waveform,

So, I concluded that 600 watts is not as much of an overkill as you might suppose. Nevertheless, because this test was done with music much louder than I would actually use I bought some new amps which are only(!) 350 watts into 4 ohms, and they are OK. (I did not buy some 60 watt tube amps which I had been considering). In general, my experience has been that every time my amp power has been increased the speakers sounded better. I think that high powered amps have characteristics other than their maximum power capability which are helpful.