Please explain

By definition a watt is a watt. Some say tube power is more but I think it is because a tube amp generally clips more gracefully giving the idea it has more power than it does. I would like to see a 20 watt tube amp stand up to a 200 watt solid state at 20hz. Volume wise, you know as for loudness, there's not much difference in 20 and 200 watts. Generally, at reasonably sane levels, you don't use but a few watts anyway.

Watts are Watts period. The SOUND is what most vendors refer to. Normally tube amps have more distortion but distortion is in even ordered harmonics, which sounds more pleasant. SS has odd ordered harmonics, which tends to sound harsher. For some of us the tube can be played louder with less listener fatigue because of this.

SS amps usually have more HEADROOM for transient music demands, tube amps with low power have less headroom so overall demands cannot usually be met at a equal higher volume level for a low efficient speaker if comparing SS to Tubes. This is why we prefer efficient speakers and speakers with less electronics in the way. Efficient speakers do not require a lot of current to produce signals at the max sound output, which usually is somewhere between 100-107db. This way a 8 watt amp can put the same Decibels out as a 400 watt amp, as the speaker just cannot go beyond this without physical damage.

The tube amp is usually the least expensive part of the overall equation as higher efficiency speakers can be very expensive compared to a lower efficiency counterpart.

barone.

ive tried ss vs tube & measured both wattages & spl in both type amps,the theory of a tube watt being more powerfull than a solid state watt is nothing more than a myth, a watt is a watt.

the main differences are as bigtee pointed out that most tube amps will continue to produce power through a clip where a solid state amp will not, the other difference ive found is a weaker bass response from tube amps that i attribute to their extremely low damping factors.

bigtee.

the difference between 20 watts & 200 watts is actually pretty large, every time you double wattage you gain about 3db in spl, 10 times the wattage is approx twice the volume.

I think the point about 20 vs 200 is that if you have any hearing left you are usually only using 5-10 watts of power (even on inefficient speakers). At reasonable volume levels you should not be running at full tilt.

The more amperage that a given watt is composed of, the more powerful that watt sounds (IMO). Watts have both an ammperage component and a voltage component. Someone with a more technical background could give a more scientific reason why, but 125 Sony watts do not sound nearly as powerful (not to mention musical) as 75 parasound/pass/YBA/etc watts.

I think your question goes more toward impedance matching of the speaker to the amp, rather than "what is a watt?"

I am no expert, but I will copy the explanation that Coincident Speaker Technologies gives:

Loudspeaker Impedance And Amplifier Matching
06/29/01

Solid State Amplifiers:
With transistor amplifiers ,the amp's output impedance is never matched to the load it drives.The lower the load impedance ,the closer it comes to a true impedance match , because the output impedance of a solid state amp is very low - typically a fraction of an ohm.This helps explain why (all things being equal- and the amplifier has sufficient current capability)4 ohm speakers produce greater acoustical output than 8 ohm speakers.The lower impedance speaker offers less resistance to current from the amp.The transistor amp sees less resistance into 4 ohms , therefore its output stage delivers more current.

Tube Amplifiers:
A tube amplifier's output stage(s) are totally different. A true match between the load impedance and the plate impedance ( or plate - plate impedance of a push - pull tube output stage) is never absolutely possible.The tube's plate impedance is typically exceptionally high
( thousands of ohms.) Therefore ,even a tube output transformer ( which becomes necessary to lower the plate impedance so that a typical speaker can be driven) with a primary impedance of 3K - 8K ohms will not closely approach this match. Therefore, it can be seen that the operation of tube versus solid state outputs is reversed. In the case of transistors, impedances cannot be matched due to the ultra low output impedance of the amp ,while with tubes, the match cannot be achieved because of the very high output impedances.

The output transformer in a tube amp lowers its impedance to a level where speakers can be made to operate and extract power from the driving amplifier. The output transformer is designed with a given ratio between the number of turns of wire in the primary and a nominal secondary impedance. For example, if we connect an 8 ohm loudspeaker to an amplifier with a primary impedance of say, 5,000 ohms and a transformer tap of 8 ohms, the primary impedance remains at 5,000 ohms and the amplifier delivers a given amount of electrical power. But ,if a 4 ohm speaker is connected to this amplifier, the output volume will diminish because the 4 ohm load causes a reduction of the primary winding impedance. This reduction means the amp's output transformer presents a poorer match to the plates of the tube output stage than it previously did.

On the other hand, if a 14 ohm loudspeaker is connected to the same 8 ohm tap, the primary winding's impedance is increased. The transformer represents only a ratio of turns and its impedance is determined by the load connected to it. Because the transformer's impedance has increased, it comes closer to matching that of the plate circuit. The result is greater output volume from the speaker.

In conclusion, a tube amplifier will produce more output ( greater voltage delivery) into higher impedance loads. Therefore , a 14 ohm speaker will be much more efficiently driven by a tube amplifier than will a 8 or 4 ohm speaker. This becomes of critical importance when using OTL or single ended triode tube amplifiers when available output power is low and amplifier output impedance is very high.

To fully realize the inherent potential of al SE triode tube and OTL amps , a loudspeaker of 14 ohms or greater is mandatory. Anything less involves a huge compromise.

Now that you are likely totally confused, as I was when I first read this, I think the main point is that, based on impedance matching, if you are using a high impedance speaker, then a tube amp will produce greater volume with less power, and conversely, a solid state amp will require greater power to get the same volume from the same speaker. At least that's how I understand it.

If I am totally off base, I hope some electronics whizz will set us straight.

Watt= volts x amps If you increase the amperage then you must reduce the voltage. If a amp is driving a low impedance load, then amperage would be a factor you would want to look at. Most solid state amps double down into lower impedances. This would tend to increase the amperage because the power supply will only provide so much voltage---simply speaking. It's actually a little more complicated than that.

Bigjoe, That's correct but a double of the volume is not going to be worth much because the louder the average volume the more likely you are to clip peaks. To me, this would be the value of a powerful amp. Not so much volume but to have the sound cleanly reproduced. Suppose you're using a average level of 10 watts and a 20 db peak rolls through? This is why I say the true volume difference want be "That" big.
As to the last statement by Coffee nudge, watts are watts and power is represented by watts. I never have figured where the myths come from. Solid state amps(well designed) will usually double down into lower impedances. Tube amps have a tendency that what you get at 16 ohms is pretty much what you get at 4 ohms. Tube amps are not stable sometimes and lengths must be taken to allow operation into different impedances---hence, multiple taps.

bigtee,i agree 100% on not using all that much wattage under normal listening sessions,i also agree about dynamic peaks thats why i suscribe to the you cant have too much power camp:)

nothing