Power amplifier longevity… thoughts?


Since I’ve bought a pair of Magnepan LRS+ speakers, I am searching for a used power amp with enough power and current to drive them as they deserve.

Some candidates come to mind and searching the used market (Hifi Shark) some are available for sale, for example:

- Classé CA-201

- Rotel RHB-10

- Acurus A200

- Muse 160

- Parasound HCA-1200 MkII

- Ayre V-1X
 

The possibility of buying a top quality amp at a friendly price is very appealing, especially comparing with todays new gear prices.

But the majority have way more the 20 years and one never knows the amp history, so there always the probability of a costly repair, and even the impossibility of restoration to the original specs when no parts or the service manual are available.

I wonder, in a general way, if an quality amp (and all parts) maintain the sound quality after all those years, needed only a check and bias adjustment.

Of course, in most hi-fi gear the capacitors and resistors are usually the first to need attention (change) but can those large caps (the size of a can of beer) last longer?

 

audiofilo123

@cdorval1 at the dealer, I have listened the 1.7i with an EAM integrated (made in Italy) and they sounded ok - it was my first real Magnepan experience - but now, after living with the LRS+ for a month, listening daily, I must say that amp lacked some grip on the speakers, evident in some hardness on the voices on some recordings. Also the room was a bit small for them.


Looks like power and current aren’t necessarily for the Maggies to play loud, but to control the frequencies at both extremes… just what I have concluded so far, am I right?

Surprisingly, on the other hand, I am currently using a Naim Nap 150X (around 75w / 4 Ohms) and it surpasses in control all the >250w / 4 Ohms high current amplifiers in my collection.

 

 

@audiofilo123

Yes, it’s interesting that amps that aren’t as powerful can sound better. I think it’s roughly correlated with damping factor.  The Bryston, with 100w into 4 ohms, sounded very good indeed.   Its damping factor into 4 ohms is about 250.  Always best to listen first, of course.  If you can’t hear an amp with the Magnepans, the best bet would probably be amps with very low output impedance/high damping factor.  Enjoy!

@audiofilo123 As a general rule of thumb, the cooler the amp runs the longer it will last. Electrolytic capacitors, which are used in the power supplies of most electronics, don't like heat and so last longer in a cooler environment.

To give you an idea of this, in tube equipment the filter capacitors might go about 20-25 years; in a solid state amp they might go 30-35 years.

Since class D runs the coolest of any amplifiers, it follows that they will also last the longest. Some class D amps easily rival the best of class A amps (whether tube or solid state) as well.

@atmasphere that makes sense, Class A amps probably will require maintenance before  other types. That said, my interest lays on 5 to 15 year old amps, after that I consider them to risky.

What are the Class D you have as a reference?

@audiofilo123 I'm using my own (Atma-Sphere). There are others that are getting similar comments, such as the AGD Audion.