Basics 1.2 two brands.
Sometimes a brand is pretty good for what it is, but not really in comparison to better stuff. It all depends on what you consider good. Sometimes a brand gets a bad reputation it does not deserve.
If you like motorcycles there is a huge divide in the culture of owners. One one side is Harley Davidson and a few imitators. On the other side is everyone else. Harleys are expensive and loud and are a statement by the owner. They are not by any measure high performance. (Do not shout at me truth can hurt).
Japanese and European bikes have up to 200 hp from 1 liter and can turn 14,000 rpm. A big Harley can turn up to 6000 rpm and 67 hp.
But those owners are not after ultimate speed. They are after something else. Modifications usually impair handling, but are to look "good." All style and attitude. I am a handling type of guy.
McIntosh is a remarkably robust and enduring brand of electronics. They are famous for many things. There is the story of a roady for the Greatful Dead needing to replace some amps at Woodstock. He jumped in a helicopter and flew to the nearby McIntosh factory with wads of cash to buy new units right off the line. Tough and bullet proof and decent sounding. The famous WALL OF SOUND.
McIntosh has a sound. They are good, but I never saw it at the top of any golden eared lists. They are the Harley Davidson of Electronics. They have some unique attributes. One is the use of output transformers for transistor power amps. There are advantages to moderating the stress on components, but they do modify the sound and create a voice. In usual listening there is nothing actually wrong.
They have a lock on looking cool. Those blue lights. Walk into a dark room with music blasting and you know there are Macs in the there from the glow.
They make both transistor and tube equipment. Strangely some of the transistor stuff is made to look like the classic tube stuff.
It is expensive, but holds its value. You may have to spend two or ten times what other brands charge for equal performance, but depreciation is far less. Buy used and sell it later for the same or more.
I have never owned McIntosh. Came close once.
On several websites I often see the comment that this person or that person never liked Dynaco products. They will say they do like HK or SAE or Carver in comparison.
My first good amp was a Dynaco 400 from a kit. I built it. Big and heavy and gold. It was well regarded as second tier in the early Absolute Sound magazine. Better than Phase Linears, but not quite as good as Crowns. I got it as it was affordable as a kit and I figured I could read instructions.
If anything was wrong with it there were protection circuits that monitored power output and would limit it to protect speakers from what was then crazy levels of power. You could hear them even when they were not actuating. Very slight veil. Also the shared power supply caused a bit of cross talk when things got going.
A fairly experienced Audiophile heard this system and thought it sounded pretty good. Though not as good as his all tube set up.
A good friend had a Dynaco 120 for some time. No less an authority as J G Holt of Stereophile crowned that as the first solid state amp to beat a tube amp. Shortly after that is was surpassed by the HK Citation 12 by a hair. My friend went from his Dynaco to a Citation 12.
The next good system I had used a pair of Dynaco Mk III tube amps. Several people swore by Dynaco Stereo 70 tube amps. I also got a Citation 12. I know what these sound like.
The Citation 12 has a good reputation as a solid little unit and works really well. Its shortcomings if any are it does not add the nice even harmonic distortion of good tube amps. I have had both and have heard this so I am not speculating.
So when I see people saying the Dynaco amps are not good all I can say they never heard healthy examples. Come hear mine and prepare to eat crow.
To be fair my current beast is a bit hotrodded and tweaked. There is no protection circuit. The power supply is twinned to kill cross talk. The output is from a 416. The filter capacitor bank is HUGE. It aint the standard 400, but it is only an improvement on the standard which was pretty damn good.
The upshot of this is if you can find a Dynaco 400 it will be relatively cheap. There are 2 on the Audio Mart right now for $1000 bucks the pair.
The only "cheap" McIntosh amps you may see are bare chassis for parts. There are better available at less cost.