Basics like really basic 1.0
There is a lot of nonsense on the internet. SURPRISE!
Usable reliable and truthful information is quite rare. You can filter out a lot of crap with some basic knowledge.
First and most important is there is no best anything. All sound systems distort and change the sound of the source. I have superb sounding CDs and LPs. The LP is not always better, but I may prefer it. It is taste, it is preference. It is hearing a difference that you like, but may not be technically correct.
Golden ears sit on the mountain tops and pronounce this and that. But the mountain may be something other than stone. I know of at least one very well magazine recommended speaker that was made from quite poor materials and components. It did not sound truthful. The guy made a lot of money off it.
So let's talk about amplifiers. A basic amplifier has a simple job to do. I therefore prefer simple solutions. Separate units instead of integrated ones or receivers. Example my 1970s HK Citation 12 amp. It is a dual mono class AB quasi-complementary 60 Watt per channel Stereo amplifier. What does that mean?
Amplifier Class means the type of circuit used. It is not in any way a quality measure. People that promote "pure class A" as a quality medallion are full of shit. Almost all small signal amplifiers are class A.
Class AB or A/B describes that for higher power levels, above say 5 Watts, the signal is shared between more than one output device. For the Citation 12 it is two transistors one for positive and one for the negative voltage rails. Complementary and quasi-complementary refer to using either transistors of opposite polarity or the same polarity respectively.
It is not just transistors. Tube power amps are also class AB but have an elegant solution by having transformers on the output. Both tubes have the same polarity, as well tubes cannot have opposite polarity. Electrons are electrons after all and are negative. They get the opposite voltages by circulation of the currents backwards through the primary windings of the output transformer. Both run off high negative voltage rails. One output device(s) goes one way the other the other way through the windings.
So the Citation 12 has two output devices per channel that are the same polarity hence the quasi.
Dual Mono means that past the power cord both channels are completely separate. There are two power supplies so cross talk between channels is impossible.
Compare that to my Carver M200 T amp. It is rated at 100 Watts per channel. It has a funky "magnetic field" power supply but that is shared between both stereo channels. Carver is a brilliant designer, but a better marketer. ALL power supplies for audio use magnetic fields in their power transformers. (Exception being digital switching types but they have lousy current capability)
The Carver has 100 Watts to the Citation's 60, but the little one is far more clear and has better stereo imaging BECAUSE it has no cross talk through the power supply.
In terms of db the difference is 2.2 db between 100 and 60. (10 times log of 100/60)
The Carver was never SOTA, but it was well received. The old HK sounds better because of the power supply. (it was almost SOTA for a brief heady time) That is not preference, but measured performance.
So What is a Watt? Straight power. A low efficiency speaker may deliver 85 dba from one Watt of power. 85 dba is actually quite loud. My invisible speakers are rated at 88 dba / Watt at one meter distance. Thing is music has a huge range of dynamics so you actually need far more power than one Watt. The one meter figure is important as sound intensity falls off rapidly with distance.
There is a trend for some people to use tiny simple very low power class A amplifiers based on the opinion they never need any more than the 5 to 10 Watts (optimists) these little (expensive) jewels provide. For chamber music and much jazz that is fine.
For Rock, Symphonic music and loud jazz you need more power. A lot more.
For myself I appreciate the power reserve and headroom of big amps. My black box 416 is 240 Watts per channel that is four times the power of the little Citation 12. That is 6 db more. I hear the difference as more clarity and ease. It is simply cleaner. These db are stingy aint they? You dump all those Watts and get only a few lousy db.
In a pinch the Citation is good enough. It is only 6 db shorter and will get pretty loud. It is a lot better than the Carver because it is dual mono. My black box 416 is dualish mono. One transformer but two completely separate power supply rectifiers and filter systems.
Several respected amplifiers adopt the dual mono or dualish mono approach. Bryston and Adcom come to mind. Those are good units. The benefit is you get much better clarity in the stereo image. Shared power supplies always cause a fuzzy center to well recorded stereo images.
Many people will have completely separate amplifiers for each channel for basically the same effect.
As far as the tube vs transistor vs FETs thing it really comes down to cost. The cheapest decent tube amp is more expensive than a much better transistor amp.
Right now there are several tube amps for sale on the audio-mart. For $1300 you can have 35 watts per channel in a Dynaco ST70. It is a decent little amp, but not close to SOTA. For a bit more $1500 you can have a pair of 60 Watt Quicksilver mono amps. Both will need new tubes soon. Those are not cheap!
At the same time there are a couple hundred fine transistor amps on the same market for less than $1500. There is even a 250 Watt per channel Bryston for only $1000 bucks.
All these are oldish. So the choice is bang for buck really. For any Tube amplifier you can get a significantly better solid state unit for the same money or MUCH less.
For that reason I stick to Solid state transistors to drive my speakers.
As you may recall my preamp is a tuber, but the cost of a good tube and transistor preamp are pretty close if similar in quality. Currently my preamp is worth about $1200 bucks. There are less expensive ones out there. Caveat emptor.
