Tube Amp. Power ratings

Wake me when it is over. So much has been written. Should we have to suffer???

Porziob, the fact that there are OTLs that can handle four ohms is not a matter of debate. Some 20 years ago, your assertion was common knowledge, but the succeeding decades have produced amplifiers that fly in the face of that. Also, that tubes are more revealing is a demonstration issue, but one so apparent that it is easily settled in 5 seconds flat- its not subtle. If you've not been exposed to such technology yet, perhaps its time?

I should point out that if you are considering a tube amplifier, it really is a matter of the right tool for the job- you wouldn't use a hex wrench to tighten a pipe, you use a pipe wrench for that. In the case of tubes- *any* tube amp, the investment dollar in the amplifier will be best served by speakers that are at least 8 ohms rather than 4, all other things being equal, regardless of the technology of the tube amplifier.

IOW the point here is not the ability to arc-weld, as that has nothing to do with hearing- its all about delicacy and authority manifesting in the same system at the same time. This is the pervue of tubes, which is lost on 4 ohm speakers ( which really did not appear until transistors came in). 16 ohm speakers are starting to appear again, now that there are more tube equipment manufacturers in the US now than there was in 1956...

I would be interested in some commentary regarding how the fairly recent breed of solid state amps known as "chip amps" or "gainclones" fit into this discussion. As I understand it, chip amps perform best with a "friendly" load (i.e., efficient speakers with a benign impedance curve, no impedance dips below four ohms, and no difficult phase angles to negotiate). So I understand that, despite the fact that these little amplifiers are solid state circuits using semiconductor chips in lieu of transistors, the amps are generally best paired with speakers that were designed to pair with tube amps. I should note that I have minimal understanding of the more technical aspects of circuit design and amp/speaker interface. (I probably already made that clear with some gaffe in my narrative above.) I am interested in some perspective from the technical set on how best to choose speakers to pair with this new breed of amplifier.

Cincy_bob, 'chip amps' have been around in one form or another since the late 70's. The issue with them is that the form factor limits the amount of heat they can dissipate and the amount of current that they can pass. So you can damage them if you try to operate them on 4 ohm speakers. They require feedback for operation, a fundamental difference between them and tubes, which can be designed to operate without feedback.

Negative feedback enhances (slightly) high-order odd harmonic distortion, a form of distortion that the human ear can detect in levels of 100ths of a percent. This we hear as harshness or at best an unnatural sheen on top.

Thanks for the clarification, Mr. Karsten. One follow-up question: You mentioned in your post above that pairing a speaker intended for tubes with a transistor amplifier will result in tonal aberrations. Given that chip amps are generally not suited to driving difficult loads and seem best suited to pairing with speakers that were most likely designed around tube amplification, does this pose a quandary when trying to match these amps to speakers? In other words, does this leave you with one of two less than ideal choices: (1) You can pair the amps with speakers designed for solid state amplification (causing heat and reliability problems due to low impedances - not a very practical alternative) or, (2) You can pair the amps with speakers designed for tube amplification (causing tonal aberrations due to the solid state nature of the amplification).

Am I missing something here? Is there a type of speaker that is ideally suited to pairing with a chip amp?