Reliable amps

[Astrofly]

Think of all the products sold in the 1970s that came with a full schematic on a separate sheet of paper, a tool to adjust the knobs, a cloth to wipe the panel and several spare fuses in a little bag. Full service manuals were available to anyone who wanted to buy one. They weren't cheap, usually around $30-$50, but they printed, high quality, multipage technical documents sent from Japan on request.

Parts came in beautiful little Japanese boxes- anything you needed. I'll bet @Doodski can tell you what colour the Sony ones were... And what the Pioneer ones looked like. Parts deliveries were like christmas- lots of cute boxes with stuff you'd been waiting for carefully wrapped inside each one.

Companies were proud to be of service in the true sense. They wanted the reputation that their products were known for reliability.

I miss that, but I keep my corner of the HiFi world alive and try to help others where I can.

Yeah, it's sad to me that people have mostly lost a sense of this type of culture and commitment to quality. Younger generations can only read and wonder about it.

 

[GXAlan]

Not that I am remotely religious, but I figure it's been spreading the word of god all those years...

I was talking with a small sole proprietor in my area who used to deal exclusively with used gear/eBay/audiogon and is now a retailer of new gear earlier this year. He said it was incredibly hard to sell his Rotel and Parasound gear despite it sounding great and being affordable, but it was surprisingly easy to move Gryphon gear.

Make your amp clean/industrial, price it at $100 a watt, and you might still get takers with world class reliability.

“You never actually own this amplifier. You merely look after it for the next generation.”

 

[JSmith]

the amps that we usually consider that have a very good record track for reliability?

I'd suggest ATI are quite well built and would last;

Class AB AT1820 Series - Amplifier Technologies Inc.

ati-amp.com

... and possibly their NCore models, if the modules hold up over time;

AT52X Series - Amplifier Technologies Inc.

ati-amp.com

JSmith

 

[dualazmak]

I do wish he, restorer-john, has immortality.
And I also strongly hope that excellent maintenance/service policies not to belong to individuals, but to be maintained by very-long-surviving companies.

 

[ta240]

Not that I am remotely religious, but I figure it's been spreading the word of god all those years...

No harm in balancing things out... just in case...

 

[ta240]

Well I'd likely just electrocute myself trying to build my own amp and end up looking like a non-humorous version of your avatar. However, if you ever set up shop for such amps, let me know.

Start with tube amps then.
I only made my chest feel 'funny' once with 400 volts off a tube amp...

 

[restorer-john]

I believe one reason it's lasted so long is that it has temperature controlled fans to maintain cooling. They are very quiet.

They would likely be sealed ball bearing fans too. That amp is a beast.

 

[restorer-john]

No harm in balancing things out... just in case...

That's what I figured.

 

[dfuller]

The first brand that comes to mind for reliability for me is Bryston. These are amps that get punished in studio use and just keep going, and for decades.

 

[mhardy6647]

Well -- my EICO HF-81 is as old as I, and has had one semi-major rehab since the late 1950s (which I performed). It sounds great.
s/n isn't quite up to ASR standards, though, in full disclosure.

 

[restorer-john]

Well -- my EICO HF-81 is as old as I

It must steam powered...

 

[dlaloum]

its Impossible to predict the reliability of current offerings. We could find class D lasts forever if properly built. I think the Yamaha AS series amps are going to be classics one day and look like a pretty good value if I were betting man. Mc and Luxman are certainly the Rolex of amps if you have the money.

My concern with many current designs, is that they are inherently complex, whereas classic designs of the 1970's/80's are often relatively simple...

If something goes wrong, replacing caps, resitors or transistors, is relatively simple/easy and therefore they are easily maintainable over the long term - they are both reliably, and easy to fix if something goes wrong.

With designs like the Benchmark AHB1, or any of the Class D amps really, they are complex designs, with a multitude of very small and surface mounted components... In many cases, maintenance if something goes wrong is cost prohibitive, so the repairs basically involve replacing an entire board module - no actual component level repairs are done. (both diagnosis and repair are complex, and cost time.... making them more expensive than a replacement complete ClassD module!)

As the ClassD modules age, they will ultimately get replaced with more recent modules - which won't be the same as the original modules, which will have reached "end of life"....

So a repaired Quad 405 or 606 will be pretty much the same as the original, same performance etc... where a repaired "complex" amp - there's no knowing how it will perform - if the same module/board is still available - then it will have the same performance, if it is too old, and no longer available, then it will effectively mean replacing the amp (either completely or replacing the modules within the amp, which amounts to much the same thing).

These are disposable, commoditised forms of technology ...

 

[restorer-john]

Check out Bryston's back to the future program:

Index of /downloads/refurbished/bttf

 

[Galliardist]

My concern with many current designs, is that they are inherently complex, whereas classic designs of the 1970's/80's are often relatively simple...

If something goes wrong, replacing caps, resitors or transistors, is relatively simple/easy and therefore they are easily maintainable over the long term - they are both reliably, and easy to fix if something goes wrong.

With designs like the Benchmark AHB1, or any of the Class D amps really, they are complex designs, with a multitude of very small and surface mounted components... In many cases, maintenance if something goes wrong is cost prohibitive, so the repairs basically involve replacing an entire board module - no actual component level repairs are done. (both diagnosis and repair are complex, and cost time.... making them more expensive than a replacement complete ClassD module!)

As the ClassD modules age, they will ultimately get replaced with more recent modules - which won't be the same as the original modules, which will have reached "end of life"....

So a repaired Quad 405 or 606 will be pretty much the same as the original, same performance etc... where a repaired "complex" amp - there's no knowing how it will perform - if the same module/board is still available - then it will have the same performance, if it is too old, and no longer available, then it will effectively mean replacing the amp (either completely or replacing the modules within the amp, which amounts to much the same thing).

These are disposable, commoditised forms of technology ...

Questions:
Why is replacing a class D module different to replacing, say, a tube - especially if that tube is expensive, or indeed with a more modern equivalent that sounds different?
When people talk about their class A or AB amp lasting for years, does it count for our purpose here if that amp has had multiple repairs or services including part replacement? The thing about throwing away certain brands or designs is in part self-fulfilling, isn't it?
And how many class AB amps these days are also "complex" by your definition?

I do wonder if we are defining products out of longevity as much as we are designing it out. Repairs of surface mount components happen in other fields often enough, for example.

 

[dfuller]

Why is replacing a class D module different to replacing, say, a tube - especially if that tube is expensive, or indeed with a more modern equivalent that sounds different?

because replacing a tube is more akin to replacing a single transistor or op-amp.

When people talk about their class A or AB amp lasting for years, does it count for our purpose here if that amp has had multiple repairs or services including part replacement?

Replacing electrolytic caps every few years is something that just has to happen if electronics are used heavily.

Repairs of surface mount components happen in other fields often enough, for example.

Yes, the issue is that in power amps, they often need to be able to dissipate quite a bit of heat. through holes generally tend to be larger (ie, able to dissipate more heat), and less likely to damage the board in an irreparable way if they fail.

 

[waynel]

It seems very clear that some wonderfully sounding amps (I had the chance to try some of them) have a big reliability issue. I do not want to start an argument, but it is very clear that some amps of some brands have a failure rate that is very far from average.

Let’s ignore them and discuss about the good ones: what are the amps that we usually consider that have a very good record track for reliability?

Benchmark amps are super reliable , they don’t measure bad either

 

[ta240]

Questions:
Why is replacing a class D module different to replacing, say, a tube - especially if that tube is expensive, or indeed with a more modern equivalent that sounds different?
When people talk about their class A or AB amp lasting for years, does it count for our purpose here if that amp has had multiple repairs or services including part replacement? The thing about throwing away certain brands or designs is in part self-fulfilling, isn't it?
And how many class AB amps these days are also "complex" by your definition?

I do wonder if we are defining products out of longevity as much as we are designing it out. Repairs of surface mount components happen in other fields often enough, for example.

While repairs for surface mount components happen in other fields the cost of them turns an amp into a disposable item. 5 years from now will there be the correct class D module that will fit and match other other channel? Let alone 50 years like tubes.
Replacing an entire 'module' requires treating an entire part of an amp as just a single component. It really embraces the 'throw it away and ship another one half way around the world' reality that we all know now. But enjoy the 'efficiency' of the cheap amp....
Do SS AB amps typically need components replaced rather than just checked and adjust the bias?

Based on Restorer-John's earlier comment I'm half tempted to put a tiny schematic and biasing instructions in my amps, along with spare transistors with the hope that maybe someday someone would give them more decades of life.

 

[dlaloum]

The classic Quad amps are sufficiently simple, that a competent amateur with a soldering Iron can replace the core components if and when required...

And yes they are reliable - I have had no issues with mine in 30 years... (Quad 405, 606, 707)

And the fact that they run quite cool, while having substantial heatsinks, probably is part of the reason they last so well!

 

[Galliardist]

While repairs for surface mount components happen in other fields the cost of them turns an amp into a disposable item. 5 years from now will there be the correct class D module that will fit and match other other channel? Let alone 50 years like tubes.
Replacing an entire 'module' requires treating an entire part of an amp as just a single component. It really embraces the 'throw it away and ship another one half way around the world' reality that we all know now. But enjoy the 'efficiency' of the cheap amp....
Do SS AB amps typically need components replaced rather than just checked and adjust the bias?

Based on Restorer-John's earlier comment I'm half tempted to put a tiny schematic and biasing instructions in my amps, along with spare transistors with the hope that maybe someday someone would give them more decades of life.

OK. So what’s the most expensive part to replace I an amp: any Hypex module, or the genuine WE 300B tube?
Which of the two is most likely to be repairable? Which is most likely to be recyclable?
Which has the longest MTBF?
Which amp containing one of the two is most likely to have a different sound after replacement?

How does those questions work against any class A amp of equivalent or even lower power? It’s not like components used in class AB amps have never gone out of production, or been replaced with lower quality equivalents.

And can you name any.class D module that has gone out of production in ten years after introduction? Twenty? Come on. Some chip amps, maybe, but how many of them don't have equivalents, either?

The answers to some of these questions obviously can change over time. That class D module with surface mount components is obviously only viable for repair by a trained person with surface mount equipment, and that may not be the average hifi repairer today. Most surface mount equipment has a shorter life because it is technology like TVs and computers that are replaced as outdated equipment often before they fail, so there's a question of viability of a business doing those kinds of repairs. If in five years' time more stuff is worth having surface mount repairs done to them, why should we not see more qualified repairers and businesses? Car maintenance has changed massively in recent years, but the industry changed to match, didn't it?

But to say that one technology is more reliable than the other, as a general case, I'd say is wrong. Looking at the question today from a historical viewpoint (my fifty year old amp is fine) puts blinkers on the requirements and infrastructure needed for an amp bought today to be reliable or worth keeping into the future. That module may be fully recyclable and still cheaper than maintaining a high power class AB amp built today, with today's components. What we need maybe are the standards of fifty years ago, not necessarily the same products.

A point relevant here is self repair of products, which will demand module replacement as the repair. I do see this as a problem for people used to maintaining their own equipment, which is part of the hobby here after all.

Finally, my point of view here may be different to others because my amp is a Marantz PM-10, where the modules are part of the amp, but hardly the percentage of the product that a reference build based Hypex or Purify power amp would be.

 

[Klonatans]

I used Naim Nait 5i and Exposure 2010S integrated amps for 13 years without any issues. If I hadn't sold them most likely they would still be in a perfect working order.