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Class A Power Amp Degredation

Dear Forum Members,

I've read in several places that because class A amplifiers run hard all the time and most people don't cut them off, they wear our faster. Plus, because they remain on all the time they burn much more electricity and generate lots of heat, some more than others, at least that's what I'm told. I wonder what happens if I have to go away for a day or two?

I can't afford to purchase a brand new class A amp so I wonder if I should even consider the purchase of a used Mark Levinson, Pass Labs or other class A amp? The only amplifier I know of that can be switched between class A and A/B is the Plnius. I am told that this amp only run very hot when it's running in class A.

Here are my questions:

1. What should I look for in a used amplifier?
2. Do class A amps wear out faster than other amps?
3. Are there amplifiers that can match the musicality, sound staging, bass and sweet sounds of a class A amp? In other words are there any class A/B amps that have all of the quailities of the class A amps?
4. If I do decide to buy a class A amp how far back in years should I venture? Right now I am considering the Mark Levinson 27 or 27.5 or Pass Labs X150/250 and X150.5 and X250.5 amplifiers. It's been suggested that the Mark Levinson is more musical????? I just want to get the best amplifier to run my audio system.

I will be driving Magnapan 1.6 speakers which does require a fair amount of amps/power to drive them. Also I mostly listen to classical music, large/small scale choral works, contemporary and gospel music and all modern jazz. I love the human voice. I also love a huge sound stage with lots of depth perspective.

Any assistance and suggestions you can provide will be very welcomed. Thank you so much for taking of your time to respond to this plea for help.
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atmasphere's avatar
atmasphere
11,760 posts
 
Hi Warren, The Zu Definition is available in a 30-ohm version. All the reports I have is that this version of the speaker is really something to hear, and it can be easily driven by smaller tube amplifiers, which will sound a lot better driving 30 ohms than they will 3.3 ohms.

If you are set on going solid state, I would consider one of the First Watt amplifiers, rather than something that makes 300 watts. The First Watt amps need more efficient speakers, but they also sound better- and will be very happy with a 30 ohm load, should you decide to go in that direction.
warrenh's avatar
warrenh
2,299 posts
 
I am currently driving my Definitions with 35 glorious Bel Canto SET wpc with NOS tubes, and am very happy, indeed. Every now and then, though, I would love to know [even though my 35 SET wpc get me some serious dbs] what 122db sounds like with some particular music I love to listen to. Original question? thanks again.
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edwyun
244 posts
 
If you do plan on buying a used amp that is around 15 years old, I'd replace the capacitors. Other than that, most SS amps (like the Levinsons, Krells, Pass Labs, etc.) are built conservatively such that they should last decades without fault.
guidocorona
4,298 posts
 
Edwyun is correct, in that my Rowland 7Ms came out of the factory in the late '80s and are still going strong after 2 decades. . . except for the monthly power bill.
elevick
2,636 posts
 
Warren, you don't want to experience 122db. It hurts. I had Cornwalls, 102db/1watt, running from a Threshold 400A and a Yamaha M-80. I never made it past 1/2 volume. This could get well over 128db if you do the math. If 110db is THX, 112db is Ultra THX, what is 128db, nuclear THX or New Years fireworks?
Personally, I liked running my 20 watt SET better.
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