Sonic Nivarna V's Reliability-class A Amps

[Critter]

Hey, being that my business actually IS "Sonic Nirvana" I'm up for this :)

First up, I have run high-Class A-bias amps and pure Class A amps over MANY years with only one failure. And that was a Hafler DH-220 where I'd cranked up the bias about 8 times over spec (as many people did because they sounded better that way).

I had a DBA Illusion 1 that ran very high-bias as part of the design. It was built in 1992 - a friend owns that amp today and it has never missed a beat. On a test bench a couple of years ago, it was absolutely to orginal spec and I had the ex-factory test numbers on that unit to compare.

Tubes are a little different as they have a particular life, they are practically organic things - well they seem that way even if they aren't :) You do get quite different reports about how long that is, regardless of the methodology.
With the Atma-Sphere things we have, they have a 2-stage turn on, which if you are a bit patient gives the tubes an easier life and they will last longer. Maybe 5000 hours-ish typically and you pull one out and stick another one in, easy-peasy.

IMO it is all about the approach you take. Meaning, do you want a Benz Sports or a Ferrari?
The Benz Sports is logically everything you need, and an immensely satisfying bit of kit. It is the analogue of a Class A/B transistor amp.
The Ferrari needs more attention and occasionally might let you down. But it is the ticket to ecstacy. It is the analogue of a Class A tube amp.

Music is so important to me that I will choose ecstacy over immensely satisfying every day.
The Atma has never let me down although I have replaced a $20 tube. It has given me absolutely breathtaking and memorable moments though. A transistor Class A/B amp never has.

[Rick]

Class A amplification doesn't have to be unreliable, and in fact the class A amps I have are very reliable.

It also isn't necessary to have excessively large amounts of class A bias, 20-30w is enough (and is BTW, very high).
Any more than this and it is usually at the expense of dynamics, reliability, and excessive heat.

I don't agree with the above posters about the tube/SS opinion, as my experience has shown the very best from both camps to be arguably audibly identical.

I feel that the 'emotion' often heard and discussed is due to the high distortion products of some tube amplification.

You will find that 95% of recordings go through many different processes before they arrive on your CD/LP, all these processes will be SS.

Rick.

[Tweaky]

This topic needs discussing.

I remember in about 1984-85 a discription of the "Absolute Sounds" yearly get to gether at Harry Pearson's place at "Sea Cliff' when all staff were present listening to the "MEGA" system .
Infinity IRS,Goldmund TT and Jadis J200 monoblock tube amps.

The Jadis amps blew up,with much fire,and took out the whole of one side of the IRS tweeter array.
Much Joy was lost,and hence Harry Pearson [in his infinate wisdom] decided to bring about the department of reliability.
Much was spoken
about this,not much forth came.

My question is.
Of those running Class A amps,or those that have run amps Biased far into class A for much of their operating power.
What is the failure rate component wise?
Is thermal drift ,again component wise an issue one should be wary of?
What would be considered a "GOOD' life for a Class A biased amp-IE" Longevity?
How far would the original parameters [Spec's] drift out of say a 3 year period?

I think these are questions that have not been answered ,let alone asked. :)

Anybody?

[Daemon]

I would compare class A tube to a Bugatti; it's a bugger to keep it running properly, and loves to have its bits tickled, but damned when it runs at all, it runs everything else off the road. In reality there's such a variety of A tube that it's all a bit general. Low power SET has good reliability, high spec drift in the tubes is common with time and temp. The various high power power tube amps are more the Bugatti type, they can let go in 2000 hours, 200 hours, or 20 hours and it's a lottery. Modern designs tend not to take the rest of your sysem down too, but the more essoteric simple is better implementations can crash everything around them still.

Class A solid state is definitely a Benz; a bit of care with polishing and it'll outlast most things on the road but there's no real romance (excepting some of the super cheap class A or high bias AB that can often use under spec components; these are like fiats, they come from the same parts of the world as Benz, Audi and Volks, they look as good, but they're made with bent tin and spit). Spec drift in transistors is minimal and MOSFET are extremely reliable inside their power rating, and cheap enough to gang so that they usually are well within. Component spec drift tends to be in the realms of the usual suspects; capacitor sometimes with time and temp, coils with time and abuse, but in general, it's more or less eternal as electronics go.

Hybrids strongly depend on implementation. If the valves are chosen and implemented well, they're as reliable as SET but less prone to spec drift by at least an order of magnitude. If chosen and implemented poorly, they can be as dodgy as high power valve gear. Good ones have the power, performance and reliability of a Benz, with a bit of the romance of a Buge; they're the audio Ferraris. For power amps in class A, this would be my choice when looking for the thing with it all (though I chose class D, because I've come to believe that the thing that makes anything with valves so tasty is the lovely filtering through the valve, and I've more or less decided that I want to keep a tight reign on this by keeping it in the pre area. Still, as I explained to my wife when she raised her eyebrows at the protruding valves on my CD, every valve has a little bit of god inside.)

Objective measurement is slim on the ground in either case.

[Critter]

Fair comments Rick.

My comparison involving the transistor A/B and tube Class A were simply as a means of comparison though.
Making a point I guess that I'll take a little "potential" maintenance etc to get what that might bring to the musical table, as it were.

Personally, I am still waiting to hear a transistor amp produce music that gets to the level of the best tubes, despite having heard plenty that were supposed to.....haven't heard them all though.

As the Yanks say, Your Mileage May Vary.

In the end, you go with what best communicates the musical message to YOU, in your system, regardless of whatever is in play technically.

A Krell will murder a tube amp if you measure it, but they generally make me want to leave the room :(

[Rick]

In the end, you go with what best communicates the musical message to YOU, in your system, regardless of whatever is in play technically.[/b]
Of course, I would never say otherwise, if you happy with what you hear, don't change because some else says so.


A Krell will murder a tube amp if you measure it, but they generally make me want to leave the room :(
[/b]
That may be the case, however there must be a reason for this, and I like to find out why.
IME, there is usually something else going on in the system which is at fault, I can't say I've ever heard a Krell (which is to blame) make me want to leave the room, though I have heard some which aren't so great.

I have heard countless systems using tube product which have sounded utterly disgusting, only to see the owner/operator in awe of how great they feel it sounds. This is why I feel many people prefer the many distortions which come from these systems.

As I said above, I'm not a tube knocker, as I've heard some utterly superb ones, however there are also some seriously flawed units around, and interestingly, they quite often are the ones which are said to have 'emotion'.

Rick.

[Daemon]

When you put it like that Rick, in terms of sound, "the best of both camps are argueably audibly identicale", I'd agree. Though on those terms, the "best" tube stuff isn't usually the ones considered by the officionados to be the "best" tubes. My taste in amps may be aweful, but I like the Van Alstine style tube amp; hyper accurate, rather than the mushy warm and fuzzy style (which is probably why I don't mind the new class D sound).

Still, if one of you wants to give me a pair of audiopax monoblocks, I promise to tell you what I really think of them.

In terms of reliability though, I think most solid state beats most tube gear, though it's my subjective opinion only. Perhaps it would be fairer to say, I think you have more chance of having a long trouble free run from any of a wide variety of brands of high quality solid state, than from any similarly wide selection of high quality valve amps, but that hybrids sit in the middle and can be as good as solids, within their valve life.

Critter, I've never heard a Krell that made me want to leave the room, yet, but I've sure heard a few that I thought might have been designed with a view towards playing alot of rap, house and hip hop :wacko:

[Critter]

:)
Perhaps "leave the room" is overstating things....however they leave me cold and disinterested. Not wanting to pick on Krell, it was just an example.

As for "tube sound", I'm much like you Daemon, I think.
The warm, euphonic sound that people most often think of with tubes is not my cup of tea either.
The Atma's are far from that - fast, incisive, transparent and grainless. They are not the "emotional" style of thing.

I'm yet to hear a transistor amp that produces the palapable, holographic sound they produce. There-ness.

Which is not to say they don't exist, I just haven't heard them. A Levinson Reference of a customer's came closest, fantastic staging, I'd be happy enough with that :)

I also haven't heard an Audiopax and would like to as well.

Without doubt there is no point in suggesting that tubes are inherently better than transistors - or vice versa.

To get back to Tweaky's thread, the cutting edge in either form is special and worth the trouble. I guess it's a case of what floats your boat. For me that's the best tubes.

There is also the fact that there is a particular technical case in favour of a current-source amplifier when driving full-range speakers like the Zu's I have here.

[Tax]

Best of both worlds approach Pathos Hybrid Integated Twin Towers is what I have, 2 12AUX7 (5751) valves in the input stage and solid state output stage runs in Pure Class A.

Lives somewhere in between 'emotional tubes'and "cold solid states" and works very well with a certain speaker owned by Critter :-)

I have heard Critters Atma-spheres and they are a very good match with his Sonata's.

Re the original question of reliability, so far so good. I take the same approach to valves as I do to my car and home always keep a spare light bulb handy. Same goes for tube amps as long as it isn't a complicated layout, replacement valves not too expensive, no biaising issues..well then have a spare handy.

It luck of the draw as with anything else in the Universe, Last year I bought a Panasonic DVD Player/VCR Recorder (two in one job) took it home, played a DVD..all was OK, Played a VHS tape and it kept spitting it out after about 10 -15 mins.

Took it back to Bing Lee who kindly pointed me to the Panasonic Service contractor in my area, who kept it for a couple of days and sent it back saying there was nothing wrong. Brought it back home tried it again same thing happens, take it back again told nothing wrong, brought it back tried again and same thing happens.. I just gave up even though it was still under warranty..it was just too hard emotionally, mentally and physically to battle it out over a $500 - $600 item.

Only think that came of it is that I vowed after many years as a user never to buy PANASONIC stuff again.

I would rather give the Koreans and Chinese firms a go and save some money in the process..

Again re the reliability debate/discussion..go figure

[Daemon]

The Pathos stuff has a reputation for good build and reliability. I looked at that twin towers amp myself; quite a nice thing.

As for you Pana' combo: Pana' stuff isn't usually bad. I've had similar complaints regarding them from customers though (I don't sell any electronics, but I do database my customers problems with theirs), and as far as I can figure, the motors in the combo tape drive are nowhere near as gutsy as they should be. A tight tape, or any tape that's been run off a twin capstain player with wear, may cause them to stop and spit the tape, because they think the tape is jammed. The cure so far has been to bash the tapes on their spines with a fair to middlin' degree of force, against something solid, which loosens the spool pretty well all the way through. All in all I usually suggest to my customers that a combo isn't necessarily a good deal, as the chances of both parts giving up the ghost at the same time, aren't high.

With regards to your warranty: Many mass market stores like to pretend that they don't deal with your claim (Harvey Norman is an offender), but only refer you to the manufacturer. This is not strictly true. Under Aus' consumer law, the store is obliged to accept the return and handle the warranty claim on your behalf, which saves you the hassle and the postage / transport costs and gives you someone to scream at when what happened to you, happens.

[Tax]

Thanks Daemon,

Will keep the advice in mind for the future.

cheers
Tax

[davidsss]

Don't wish to continue off topic but I've had a similar problem with my LG combo - the VHS section just won't track the tapes properly - and I've heard of at least 3 other people with the same problem with the same model - I had mine fixed twice and then it went again after the warranty. I'm beginning to be put off the combo thing totally.

Back to the topic - I have found hifi gear to be the most reliable stuff I've ever owned. My Rectilinear 12 speakers are 30yo and work fine although I do want better (next year, hopefully). My Luxman amp ran for 20 years before it died and I replaced it with a second hand Rotel. My Rotel CD player, RCD 865BX, is 15 now without a hitch and my Micro TT is over 30 without a hitch. I would be very disappointed if my stereo gear broke down as I am used to reliability. I would be doubly disappointed if it was a really expensive component. Some of those hi end amps which cost a fortune should last at least 15 years in my opinion (replacing valves doesn't count, they go, everyone knows that, and you replace them - bit like a clutch on a car). I understand some are esoteric, but they should at least last, which, going by the above, most of them do.

DS

[Daemon]

When you get to esoteric valve power amps and monoblocks, they can drop valves very unpredictably (power valves are a dodgy thing, especially when driven hard). Many of the more esoteric offerings eschew things like protection circuitry, on the premise that they colour the signal or affect transient behaviour and similar (which can often be true). Often these super esoterics are super expensive, though super simple, and when they drop a valve they can damage everything they're plugged in to, bar the power point. It's most common in models with dodgy oscillation prone designs or attempts to DC couple, as far as I can gather, though serious offenders are getting rarer it seems. More normal high end hi fi is pretty reliable stuff as far as electronics go, though old gear can often take on a new lease of life with an overhaul of dying caps and such like. You don't see most of the dodgiest boutique esoterica in Oz anyway.