One of the primary things that all class A amps seem to have in common is a sense of authority. They just seem to carry more weight or body in the music.
There are so many variables in amplifier design that going beyond that simple statement gets tricky :)
Not familiar with Clayton...but pure class a amps do not switch power classifications( such as a/b amps)...run hot...as they give you all they have all the time...and are much truer to retaining an original square wave signal...however...since most general low-level listening doesnt require gobs of power or head room...class a/b amps operate in class a more than one would think....or that is my very limited understanding...sure others will chime in...happy holidays....
Yes many A/B amps still operate in class A up to the first 1 to 3 watts, and if you've ever watched an amplifier with power meters while the music plays you are usually amazed at how much of the time the meter hangs around 1 to 5 or so watts. It's the 20 db peaks that get us...
Not all "class A" amps are PURE class A, also. I had a 50 watt per channel class A Forte model 1a which I think is a good amp and sort of has the classic class A sound, also had the original Music Fidelity A1 25 watts per channel, the sound was a bit on the rich, warm full sound, not at all harsh, strident, thin, or analytical. I believe that is the sort of thing most would agree is the "Class A experience". I would imagine an extremely expensive pure class A amp like the big old Thresholds, Levinsons, Benini, Krell, etc. would give a better representation than my Forte 1a.
"many A/B amps still operate in class A up to the first 1 to 3 watts"
Xiekitchen that's what I thought too. Then a recently read somewhere some blend class A with class B and it's not a pure switch over.
Not sure of the technicalities but it appears that some class A/B amps never operate in pure class A at all.
Stereophile said class A amps are not good for rock music. More classical, jazz, etc.
I have used several amps that were considered class A. I was a dealer for Krell and Musical Fidelity and had a pair of Stax DA 80s. The common feature was a lack of hardness in the top end. But I don't think being class A is a critical feature, it is just part of the overall design of the amp. I prefer the sound of other amps I have or have had to the sound of the above. Disclaimer, I used the earlier generation Krell , the current top end ones are much better , but at a very high cost. The current Musical Fidelity amp[M3] I use is much better than the 270 of years ago which was class A . The Meridian 605s I use are Mosfets , they sound considerably better than the KMA 100s which were their contemporaries. I think you have to review the overall performance of a given amp and how it will fit into your system rather than deciding on the basis of general design principals.
I would have to agree...an amp is either a good amp or its not...regardless of design...there are those that put a high value on specs, distortion,etc...but listening is the key...that being said...i used to have an early Musical fidelity a series as well...great amp...im an idiot for letting that go...but they did have some reliability issues due to heat...and the fact that some place other componets on top of them(bad idea)....Sugden is another famous class a company....
Own the Sugden A21SE integrated. I've owned very good SS/tube amps over the years, a myriad of English, Japanese and American built. The characteristic that most impresses me with the Sugden is the lightening quickness. I was convinced that I had owned fairly quick amps in the past with great attack, but this thing is in a class by itself. The vocals and acoustic piano are quite good, bass is remarkably solid and quick.
The midrange is not quite as sweet as say my VTLs were. Imaging seems very respectable although I wouldn't say it floats the instruments in an airy way. I'm running Coincident Triumphs with 93db efficiency, so it doesn't have much work for a 30wpc amp.
For some, Class A is an article of faith, for others just a myth.
Given the inconvenience of high heat and the added expense of building Class A, it's an awfully high maintenance myth, if it is one.
Cdc, just for the record, anytime you are 'mixing' class A with B, its called A/B. IOW that's the definition.
Also, Class A amplifiers are the best at rock- Class A should be the best at everything, FWIW. If Stereophile said otherwise it is only because they are completely dead wrong.
This is not to say that 'all class A amps sound better than all class A/B amps' or whatever, since there are so many design variables that exist. But class A, as a class of operation, is the best for all types of music.
Well, getting back to the question Ralph. I think Mr. Carsten is entirely correct . True class A amps have muscle if you can imagine that, Yes they great for Rock you must have read that wrong.
The signature is a tad of warmth Atmasphere amps aside, and are willing to play the bottom octave if need be they to. The amp will truly double their output
This happens whenever a split in resistance occurs let's say Clayton says it will generate 100wpc at 8 OHMs that's what they mean for a linear lab generated 8 ohm resistance. When in true life they double their out put to 200WPC at 4 ohms and so on, for every drop in resistance, if the amp is built to work at 1 ohm, like Krell.
That finally before burning the to amp to pieces at 1 ohm the amp generates an incredible 800Wpc.
Authority yes and finesse and sweetness, when called for. The early ML-20 monos had it 40 years ago and how wonderful they sounded on the Quads or later the Servo Statics. Anyone remember?
And Ralphs own now on my Sound Labs, which is a difficult load for the MA-2 Mk. III's 220 watts but it easily betters the Siegfrieds in triode mode at about 400 watts and only in pentode mode at 700 those beasts equal the "authority" of Ralph's OTLs and considerably more cost. Just go figure.
Thanks Atmasphere. Wish I could remember where I saw that article.
i have auditioned three class a amps. they sound different. my favorite was wonderful from 200hz and below, ok from 200 hz to the upper midrange and unsatisfactory from around 1000hz and higher.
i have owned and auditioned class d amps and other non class a solid state amps. i have a problem with ss amps in the upper mids/lower treble and with all but the most "well behaved" tube amps.
it is possible that some class a amps may be "kinder to the ear" in the mid range region, but too many are not.
i owned the ml 2s, i believe it was called, 25 watts of class a. i used them with a pair of quad 57s. they were not my amp of choice. the overall presentation was dry--no romance, no bloom. quads need tubes. while solid state may provide good bass response, i would not want to listen to violins, harsichords or cymbals.
Yes you are right, they were called ML-2s. I had forgotten and yes, they sounded a tad dry, you are right there too, but at that time I could live with that because of their finesse and speed and I stuck with them until I discovered Jadis. You should try to audition a pair of Jadis 30 watt monos for your Quads. You might like them.