So tube amps have more current on tap than ss?
Not as a general rule; more often than not the opposite would be true. It goes without saying that generalizations are not likely to be meaningful if drawn based on a comparison between a $349 amplifier and amplifiers that are in a VASTLY different league in terms of performance, quality, and price.
... what about musical dynamic peaks? That's what I'm, mistakenly(?) trying to get at. If you play a song at 90 dB with 110dB musical peaks like rim shots, don't you need the current to give that dynamic range for the 10 milliseconds?
Good response by Bombaywalla, of course, to which I'll add some further specifics.
I took a look at the
specs of the Zamp, and it appears that what Ralph (Atmasphere) surmised about the 12 amp current spec is correct -- it most likely represents how much current the amplifier can supply into a short circuit (zero ohms) for a miniscule amount of time. Also, I would infer that the reference to 12 amps "peak" probably means "peak" not only in the sense of maximum, but also in the sense of being distinguished from
RMS, which is the form in which the voltages and currents corresponding to maximum continuous power ratings are defined. For the sinusoidal waveforms upon which these numbers are based, RMS current equals peak current divided by the square root of 2, so on an RMS basis the maximum current rating is only about 8.5 amps.
In any event, what is important to realize is that the specified peak current is unlikely to ever be available to a real world speaker load, because for a reasonable load impedance the amplifier will not be able to supply the voltage corresponding to that current times that impedance, and it will not be able to supply the power corresponding to that current squared times that impedance.
What I think you are really asking about in this question is what is referred to as dynamic headroom, meaning the ability of the amplifier to deliver greater amounts of power to a speaker for brief amounts of time than its specified continuous maximum rating.
Dynamic headroom is often unspecified, and when it is specified there is often no indication of the amount of time the power increase can be sustained for, so comparing that spec for different amplifiers is usually not very meaningful. Also, having more dynamic headroom is not necessarily a positive attribute. It can be looked at in two ways: The amplifier is ABLE to deliver more power for a short time than it can deliver continuously, or it is UNABLE to continuously deliver an amount of power that is close to what it can deliver for a short period of time. Some of the world's best amplifiers have essentially zero dynamic headroom.
My impression is that typical dynamic headroom numbers range from zero to a few db, and rarely if ever exceed or even reach perhaps 6 db. 6 db corresponds to a four-fold increase in power, and would raise the sound pressure level heard by the listener by no more than 6 db, and perhaps somewhat less due to "thermal compression" in the speaker.
A number that generally says more about the robustness of a solid state (but not tube) amplifier than all of the foregoing is how closely its 4 ohm continuous power rating approaches being double its 8 ohm rating. The two ratings for the Zamp are 45 and 60 watts, which may be a better ratio than most other amplifiers in its price class have (many of which do not even have a 4 ohm rating), but does not approach the factor of 2 that many multi-kilobuck solid state amplifiers can achieve.
Regards,
-- Al
