Class A amplifiers


I was watching YouTube reviews on Hifi and one guy said if you like Class A amps you have to accept that every 3 or 4 years you have to send them in to get serviced Becasue the heat inevitably causes issues? Is this true? I have a friend with an older Maek Levinson Class A amp and he was looking to sell,it to me, and am just wondering if Class A amps are like a boat, always costing you more . Anyone?
bear1971
I have a Spectral DMA 200 that sounds wonderful driving a pair of Magnepan 1.6's. I have tinnitus so I can't hear the cooling fan. And yes, it helps keep the room warm in winter. Not bad for a 34 year old amplifier!
doesn’t spectral only work with spectral pre amps and cables? Isn’t spectral a closed end system or no
Who remembers the Threshold T200? Pure Class A. It was produced about ‘92. Jon Soderberg services all Threshold gear. And the Plinius SA MkIII was for my money the best Class A and Class AB money came buy. It was produced about 1999. 

The weakest link in any electronics is ALWAYS the electrolytic capacitors (also maybe mechanical relays too, but for this specific conversation, they do not quite matter).  One of the most important factors in their reliability is the temperature and the voltage they are exposed to.

In theory, since class A amplifiers run hotter, all else being equal, it is possible that such capacitors may degrade and eventually break down, sooner than they would compared to other class of amplifiers.

However, if the capacitors are chosen to be of a very hi quality (very long lifetimes & very high temperature & voltage capability), AND they are appropriately placed in the amplifier enclosure where they are not always exposed to high temperatures, they could in theory, last quite a long time.

So, a blanket statement cannot be made but it is something which depends on a lot of factors.

Take this capacitor for example, it is extremely well made, have a very long life and they can withstand high temperatures (37,000 hours at 105C).

https://www.digikey.com/en/products/detail/kemet/PEG130MH3900QL1/4918903

If similar good components are used throughout, your amplifier will indeed last a long time too.




mrmeaner13 posts06-13-2021 2:47amI have a glorious Class A Sugden A21SE and it never misses a beat, I contacted Sugden and asked them about having it serviced and he said it’s likely not to need looking at.
In my opinion class A can’t be bettered.

It is a fantastic amp! Mine is driving Tannoy Eatons with no issues. There are original a21’s still going strong 30 years later....Sugden, the very first commercially available solid state pure class A, since 1967. Some very ill informed people post here....notice the gigantic heat sinks that adorn both sides of the A21se...the amp is a brute! It is liquid, textured, detailed, holographic, and powerful...at only 30 watts/40 into 4 ohms....50% larger power supply than the previous A21 model, non se version. Built in the UK by one of only 12 employees...even comes with a tag indicating all who had their hands on it...worth every penny of the $3250 paid. When combined with Tannoy legacy, prestige, or gold series speakers, it is pure sonic bliss...end game combo. Add your own tubed phono preamp and it gets even better...Tavish Design makes some great phono preamps.