Power Amplifier Longevity

I would certainly look at current Pass 250.8 etc as an old amp will need new caps. Pass is very reliable with great resale. Good luck.

Are you looking for an amp for the L/R speakers or for all 7 channels? Is the Marantz a pre/processor? 

The same length of time as stuff that isn't separates!

Caps 20 years.

Yes, I failed to mention that my Mozart Grands will most likely be powered separately by a Wyred4Sound ST-500 class D that I already have.  So the Lexicon CX or LX will power the Center and Surround Channels.  The LX-7 is attractive as it appears I could bridge channels for the center speaker for more power there and run the 4 surrounds from the remaining.

Yes, the Marantz is a Pre/Processor.  Model AV8802A.

Thank you

Also depends on how well the unit was tacked care of. People tend to confine their equipment to small closed in spaces with very little ventilation. Heat will greatly reduce a component life span.

So it seems the caps are the main concern.  Are these serviceable and if so, does the investment make sense to service or buy new at that point?

It depends on the quality of the original - how good are the parts? How conservatively are they used/specified?  I have 100s of products out there and the basic answer is "30 years and counting".
The limiting factor in a good product is electrolytic capacitors.  20-30 years, iff they are very good and run well below their rating, is typically life.  But i've pulled 30 year old caps that are leak-free and working well.
You *can* have it re-capped but that is labor intensive and costly. I've recently done or had done for folks, about a dozen.
Or, of course you can play some roulette and let stuff fal and then fix it. The concern with unfused speakers is that you could do some downstream damage.
All my main gear is 25+ years old (of my own design, mostly prototypes that I keep) and works a treat. Of course i have friends in low places.
G

My advice would be to go much much simpler and newer.

Get an Anthem MRX 720. Add a stereo amp if and only if required.

Trade in your Marantz, and avoid the amp jungle.

It's all about the cap's . The cap's will dry-out, in older equipment 20 -25 years old you can bet they cap's are dried-out. Find and old school repair guy in your area - recapping the amp and you will be in-great shape. 

If you look at what is inside each component you will see a few things that stand out. Circuit boards, power supply capacitors, transformer, etc. Power supply caps are not that expensive like Nichicon, resistors and capacitors vary in cost depending on the brand and what you are trying to accomplish in sound. The circuit boards can go bad over time depending on the heat. All that being said, almost all components can be repaired/modified/upgraded. So IMO servicing is available and it can be reasonable.

I would not trade in the Marantz if you like the sound. I would only trade it in if you find something else that you like significantly better. If you think that it is not up to today's standards, send it to me for upgrades.

Trading it in for a newer amp does not mean that you will get better sound, just maybe different and that will not mean longer life either. Most components are similar in build so there are a few common upgrades that can make a significant difference for very little money. A recent example was a DeHavilland preamp I just worked on. I had already changed the transformer, volume control, added V-Capacitors, etc. The owner loved the sound but it was slightly warmish sounding and lacked a little dynamics. Changing out two resistors from the Allen Bradley to Audio Note gave it the snap he was looking for, quieter, more dynamics, more details and ore open sounding. You won't get that from any cable change that is for sure.  Less that $50 with parts.

Most of the comments here are from people who don’t really know that upgrades can be more effective and not that expensive and the component can be taken to another level of much higher priced components. Most components are built to a specific price point and not an all out build with the best parts, etc.

Happy Listening

I do like the sound of the Marantz and one of my intentions for picking up this unit is for the Atmos capability that I may implement down the road. 

Thank you all for your advice and information.  Much appreciated.

any thoughts on 'mcintosh' amps??

Buy a sugden class A and it can double as a space heater in winter! 😁 seriously though, there is nothing wrong with Marantz. I own the pm14s1 reference made in Japan and it is a terrific sounding integrated that I will never part with. The Sugden I have just sounds different, not necessarily better than my Marantz. 

Hello,
I can tell you from experience that having a really nice multichannel amp for home theater is awesome, but also very expensive. It sounds like you are trying to get two channel music an surround out of the same system. Marantz is my favorite Pre/pro. You have to realize that it is a processor. Even in pure mode it wants to color the sound in two channel. For now if you want higher end I would look at NAD class D for the center and surrounds. The processor can manipulate the sound to make the speakers blend together. Personally I would go with an Emotiva 5/4. Call them or look at the website and you will get it. You can have 5 high powered channels for the center and surrounds and use two of the slots for the 4 heights/ atmos. No risk because you can return it if you hate it. 

Now for the two channel. Now or later you would get a two channel preamp with home theater bypass. On the lower end you can go with an Emotiva USP - 1 ver 2 for $1100 retail and $750 eBay. Or on the high end Hegel for $4000. I have the Emotiva. I like that it lets you add the subs to your two channel setup and uses balanced input/ outputs if you want. 
Here is how it works: 
To listen to your system in stereo for music or TV you turn on your two channel preamp and stereo amp. High power great sound and pure as silk. When you want surround sound you turn on you Marantz Pre/pro and your multichannel amp which can be turned on using your 12v triggers along with your two channel setup if you choose. Push the HT bypass button on the two channel preamp and the Marantz controls the volume and sound of your two channel system. You can even program some of the two channel buttons on your Marantz remote so you do not need the 2 channel remote all the time. I love separates. It gives you control of your system. Later you can add a DAC to your two channel system for more better digital sound. That is a whole different thread. If your not into the music or two channel stick to my first response. Also everyone in this chat is correct about the caps on the older amps. Your speakers are very nice and I would be careful about older stuff. If you do by used please have it checked out by a professional before you hook it up. If the caps are bad or the gain or bias is set wrong you can do a lot of harm to your system. $50 can save you thousands. 

One last thing Brian339. You mentioned you might get height speaker for Atmos later. If you do not want to add the expense for the Atmos amps right now you can upgrade and add them to the Emotiva box later, You do have to send it back for them to add the amps. The amp box has seven amp bays. You can buy a five channel amp in a seven bay box for expansion later. The last two bays would have lower powered stereo amps for the heights/Atmos. Due to shipping cost just have them installed now so you are ready. Worst comes to worst you can power a second room or some out door speakers for now until you decide what to do about Atmos. The Marantz receiver can do all of this without breaking a sweat. 

  iv'e bought a used 1990's arcam delta power amp, sounds great and looks mint  .if i   h e a r   a bad sound than i might worry about caps. it has no moving parts and if it's a quality piece usually it's been well taken care of,if not than after 30 years you will see signs of abuse or humidity.if it looks good and mainly sounds good don't worry about it. lexicon's are a great  choice and sounds way nicer than most of today's amps and will pair well with modern dac's preamps and speakers.go for it.

I'm with Erik. No AV piece made more than a couple years ago is a good bet for longevity (excepting Theta Digital).  The Anthem would be a nice upgrade in sound quality over the Marantz, as well.`One of the most disastrous adventures upon which I ever embarked, as far as my marriage is concerned, was me trying to repair my aging Conrad Johnson PV 5. I didn't think to fully test the transformer until after I'd replaced all the caps and several other components. I personally, will never buy used again. The risk is much higher than people think and the opportunity cost is huge as well.

Great information to consider everyone.  Thank you.

ditto others, it is said that caps last ~20 y, but that is average, of course....initial quality of caps, how hot the amp runs(ventilation), and amount used, of course, all play a role....certainly they can last longer, but when the amp starts having a hum, they are going......also, humidity can play a role, as restistors, as they heat and cool can crack with age, and if humidity gets in there, I think that also contributes to shortening lives....

I have owned about 50 amps .In my experience things start to go south after 15 years but as the decline
is slow your ears adjust to the decline till about 20 years .

With quality gear well worth rebuilding 
the capacitors dry out ,
and while rebuilding improve  the design ,most all amplifiers or preamps 
use good reliable average parts ,coupling capacitors many good brands ,for the power supply  there to buy the best electro Lytics , get all1% resistors 
and signal path small values Vishay naked, Non magnetic Tantalum resistors brings natural character in the right areas. And for sure rewire 
Neotech makes excellent Teflon -0 Crystal copper wiring,as well as silver.
your connectors for sure make a difference ,for not much money 
WBT makes a less expensive all Gold Copper text gen for speaker terminals 
and rca, Furutech makes the best gold
or rhodium over copper IEC inputs 
from there there are many tweaks .

No AV piece made more than a couple years ago is a good bet for longevity (excepting Theta Digital)

I am a big fan of Theta, lived very happily with a Casanova for years. Really should not have sold it. Anyway...

Sadly, since HDMI came out, Theta has usually lagged the industry by years. I always worry it’s on the brink of financial collapse. It took what, like 3 years for them to introduce an HDMI ready processor?

I wish this was not true. I was really ready to buy the new Casanova. Supernova? Something like that. << sigh >>

At least relatively, the MRX 720 will be cheaper to replace than a Casablanca will be to upgrade. :)

My Classe DR3 is 40 years old of Pure 25w in Class A and works real good ;)

These are typically the factors that reduce any electronic device’s life:

1) Inrush current at turn on.
2) Temperature.
3) AC voltage spikes which causes the maximum allowable voltages to exceed for various components.

Sooooo.. pick an amp which:

1) Has an inrush current limiter (lights do not dim when you switch your device on).
2) Runs cool.
3) Components in it are rated at twice the maximum rated operating voltages.

Pass labs seems to be one of the the few exceptions where most run pretty hot (class A) and yet still are very reliable. I can only guess that they must be using absolutely superb components inside (like 105 degree C capacitors) , which may also explain their prices.

You people are a bit confused. Full of hyperbole, misinformation and bad advice. And I swear a few of you have as well, bad intentions. 
 I am sure at least a few of you will disagree. But your arguments are devoid of ANY, "actual", facts. It is "Heresey", at best, and even that's a stretch!
    Caps? What? Are they suddenly evil? Has ANYONE commenting here ever replaced a capacitor in ANYTHING? Doing it themselves OR even paying to have it done?
 Brian, Do not listen to all the Malarky, Please.
How long is an quality capacitor designed to last for? Why oh why, does everyone that has simply owned more than one decent amp think they understand electronics?

 For instance....The comment above? See #1, 2 and 3 on his "Amp check off list". He has not the foggiest notion of what he is saying. 
1, You CANNOT purchase any electrical device in the USA that does not have either an IR limiter, "The common BUS, Fuse is one type". OR IR limiting is designed into it! .It would be otherwise illegal to sell! "Per any version of the NEC"!
2, Runs cool???? Please feel free to email Nelson Pass that please. "He could use the laugh". That's about the funniest thing I have heard from someone claiming to understand rudimentary modern amplification.
3, Um......Ha ha ha ha ha, Yeah, "We tend to do better than one,  automatically"!. "That would be during the design phase of a product".
     Get my point Brain?
I currently own more Nelson Pass, designed amps than will even fit in a 12' x 12' room in my home. And I am about to put a bunch up for sale.
 I guess no one here talking about Pass amps has ever noticed that nearly ALL of them have "NO", ext. heat venting whatsoever. Heat is your friend in that type of amp architecture. The largest 2-channel he ever designed? I JUST sold mine. An orig. "X-350". It NEVER ran hot. "Surface's never above 118 degree's F."...And if it is ever re-capped? It will sound like crap and probably "begin", to run hot.
 My "Aleph 0", mono-blocks from Pass Lab's did run hot. Maybe because they were attached to the worlds largest transducers playing down, down, down to "Who knows where". But those, "Theoretically". Will double down the ohm load into infinity anyways. OR at least until they melt. "Did that once".
Caps dry out because they have burst. They leak when that happens. They burst because of misuse. Not really from age. "The capacitors built in Mason Jars, and over 100years old from the workshop of Mr. Tesla are still, NOT dry". We are still using his basic design for caps. "Except for the new super caps", "Another story"..
 There is no need to replace nearly any, modern made "Electrolytic" Capacitor manufactured in the last 30-35 years, unless the amp has failed.  Why would one fail, "cap"? Usually either a bad design of cap OR amp. And nearly always they have also been abused. "Like doubling or even quadrupling the Ohm load against the intended design. By NOT hooking it up correctly! By hooking every single component you have, "Plus a few lamps, a fan and a clock". To a single residential 15 amp circuit in which the service breaker that was past it's prime a quarter century ago.....doth reside.
  If you have good gear. Especially amplifiers. Have it fully serviced AT LEAST every five years. Every two if you smoke. Good gear will last you a lifetime IF you take care of it. I have tube amps from the early '50s with the orig. tubes that still sound and run great!
 And If you would like to try one or three of the amps I mentioned above? Let me know and we will work something out. And ALL are recently serviced, guaranteed and warrantied. BY ME! and most are in your price rage I believe. "I should tell you though, I am not a dealer. I am a collector", And a small manufacturer.
You will get out of this hobby what you put into it......Good service is not cheap and depending,. May be impossible to find locally. But there are a "Plethora", Of good shops. Most small, That will do this through Mail-Order. And plan to spend a minimum of $250 having it done. Not counting shipping if you go that route.
 Finally,  "IF, someone say's they will fully service an amp for $50? And it's not a blood relative you trust? Run....."
     Still with me Brian?

Capacitors start drying out after 10-15 years especially if used a lot .
ifprice is good buy and have all power caps,and coupling caps upgraded
I allways hav3 it optimized ,you end up witha better amp then new for less then 1/2 replace toowiring and connectors with decent gold copper ,not brass and Neotech Teflon copper wire   

The quality of the capacitors used can have a big effect on the longevity. Cheaper caps are maybe 20 years or so (I call it a 'half life' but what I mean by that is half of them that old have failed by that time). Better quality means that your half life is more like 30 years. So it is prudent to consider filter cap replacement in any electronics if they are older than 30 years! 

I know nothing about electronics, but a couple of months ago I gave the Sony AV receiver I bought new in 1991 to my nephew to use, along with similar vintage Jensen speakers rated at 8 ohms.  Before I gave it to him, I looked inside and cleaned it up a bit, and the filter capacitors looked fine (not swollen or leaky), as did the circuit boards (not dark or burnt-looking).  I found the sound to be pretty good, for what it is.  But from reading here, it sounds like a receiver that old likely has capacitors (and perhaps other parts) on the way out, and when that happens the speakers are probably going to be damaged too.  Unless one does their own repairs, does it make sense to repair something like that when it does go out?  So, use it at your own risk and throw it away when it blows?

@jollygreenaudiophile...

I guess you did not read the last part of my comment mentioning Pass Labs amps. Please read it again :-)

As for inrush current limiters, MOST devices sold today do **NOT** have such current limiters. Also, I am not quite sure how you got "fuses" lumped into the same category as a current limiting device but there is absolutely no correlation between them.

Any device which uses transformers (especially toroidals over a few hundred VAs), and electrolytic capacitors (such as the large filters on most power amps) present an almost SHORT CIRCUIT to the mains within the first cycle of the AC voltage, which lasts about 1/120th of a second. This is a very long time in the electronics world. Until the magnetic field is established on the transformer, the ONLY limit is the simple PURE wire resistance of the transformer. This can be in the very low ohms for large transformers (1 or 2 ohms max). We are talking in excess of 80 - 100 amps of inrush for 1/60th of a second. That is why lights dim for a second when some amps are switched on. In addition, on the transformer secondary side, the filter caps are a also virtual SHORT CIRCUIT as soon as power is applied. This means your rectifier is presented with a short circuit as soon as power is switched on. Again we are talking 100s of amps instantaneously until the caps start charging. Those currents, despite being on only about tenths of a second present a tremendous overload to the components, especially the rectifier and the capacitor itself.

Check out the circuit here from Nelson himself:
https://www.diyaudio.com/forums/diyaudio-com-articles/154777-burning-amplifier-ba-1-a.html

The items marked as THx (resistors with arrows thru them) are called Thermistors or NTCs (Negative temperature coefficient) meaning their resistance DROPS as temp INCREASES. Their purpose is to limit the inrush current.

Few commercial amps employ them as of today.

The point about doubling the voltage on components is simply for over-engineering. There is NEVER any harm in doing it except simply their expense. In addition, higher voltage capacitors have MUCH HIGHER ripple current ratings (check out digikey and search for them, look for low frequency ripple current ratings and ESR) which in the long run always make the components more reliable and less prone to spikes.

These things ALL add up, bit by bit, and increase the lifetime of an amp to 30 years from maybe 15....

Theta the only good maker of AV equipment? Really? Trinnov? Hello?

Doubling the voltage will NOT halve the capacitance.  Where did you get that from ?

Show me ONE graph that shows this.

Show me one piece of information in the following that indicates reduction of capacitance with its voltage rating:

https://content.kemet.com/datasheets/KEM_A4075_ALS70_71.pdf

Remember I am talking max voltage RATING not the voltage APPLIED.

As for inrush current limiters, MOST devices sold today do **NOT** have such current limiters.

All of our equipment has had current inrush limiters installed, going back 45 years. We did this to protect the AC power switches and over the years its worked out pretty well.

Hey atmasphere, good to hear your equipment has them.  Almost all transformers rated above about 300 VAs should have them but most do not.  Expensive gear is obviously better designed and it does.
Thanks

heaudio, I am sorry but you are not making any sense in your capacitance stuff.  Noone is APPLYING the higher voltage.  The voltage is FIXED at the rails.  The ONLY time it moves UP is when there is a surge.  The overvoltage RATING of the capacitor simply is able to absorb the extra max voltage which spikes so it does not blow the cap.  That is why I prefer the voltage rating to be high so that it indeed CAN absorb spikes.

There will be NO change whatsoever in the capacitance of a cap becoz of its voltage rating or by changing the applied voltage to it (unless temperature becomes an issue).

And the thermistors are NTC btw: 
https://www.newark.com/amphenol-advanced-sensors/cl-60/ntc-inrush-current-limiter-10/dp/81F3390

They have to be since they must settle to a LOW value with HIGHER temps otherwise you would never be able get more than quarter of the power of the amp since the current would be limited ALL the time.
A better (but more expensive) way of doing this would be using relays with a timer of course.

I have 40+ years old amps from Yamaha, Victor, Sony, in original condition that still rock. That said, it is risky business to use them in this condition without restoration service.

For your Vienna speakers and almost whatever else you might want to replace them with for moderate size room, there is Gryphon Diablo 120 integrated for sale here. Get it and forget about the age of an amp. Gryphons are built for 40 years of reliable operation under normal conditions. Sure, some break from time to time. Everything breaks from time to time. You don't need separates. Gryphon is higher level than Pass.

@cakyol  , @heaudio123 is correct about the can size of capacitors.


It is also prudent to follow military derating curves when selecting a filter capacitor for a power supply. This puts the voltage at which the power supply is operating to be about 70-80% of the voltage rating of the capacitor. This insures the longest life of the part. Its also worth noting that the capacitor will run longer if it is charged up fairly frequently; putting the device in storage for extended periods isn't good for electrolytic capacitors. 

Quoted from United Chemicon:

(a) Operating Voltage

When in service at voltages equal to or below the rated value, the life of electrolytic capacitors is affected less by applied voltage than by operating temperature. Figures 7, 8 and 9 show life test results with various reduced voltages applied. The curves show that the life of the capacitor has not been significantly increased by a reduction in voltage. This is due to the use of proper forming voltages to minimize gas generation and leakage current. From this we can say that when capacitors are used at or below their rated voltage, the acceleration factor AV is equal to 1.

My point in choosing a capacitor to have a max voltage higher than normal is so that it handles the voltage spikes that are likely to happen.  If the AC mains was perfect, it would not be a problem.  But if any AC machinery or any kind of inductive load is running near the outlet to which your device is connected, if the devices do not have excellent filters, they will cause spikes on the AC line when powered off.  So, a cap with a higher voltage rating will favor better than one which does not.

I am not trying to increase the life of the capacitor by choosing a higher rating.  I am making it more resilient to possible spikes over the long term.  That is the essence of my argument.

I can only speak for myself. I built a Hafler 500 in 1975-76--can't remember that far back!--and use it today.

It was in the shop recently as I was able to score an Audio Research preamp, finally!, and wanted to be sure the Hafler was OK.  

Tech said that the bias was WAY OFF for some reason, but once he adjusted it, everything measured within spec, and it sounds just fine (for a non-tube amp), old "caps" and all.

I do know that in my Sunn guitar amp they replaced the caps and possibly a few other parts, but these amps are used for playing instruments and taken on the road, so not surprised that some parts eventually fail or no longer perform in spec.

I am looking for an Audio Research tube amp to go with my preamp, and when I find one, it being tube and running much warmer than most solid state amps, I will have it checked out (can't afford a new one) for performance before putting it into the system.  Also need an EC2 or EC3 so I can keep the Hafler on the bottom end of my Maggies, so will have to have it checked as well.  

Old stuff is old; have it checked out before incorporating into your system and you should be fine.

Will something fail eventually?  Of course.  Back in the day, we got in a number of DOA items, so new is no guarantee either.

Cheers!