Amplifier servicing

[andyjm]

I get the feeling you're overreacting or you've got money to burn, buying another amp for spares seems a bit OTT. Most of the parts inside would be surface mounted therefore not easily if at all repairable, meaning a Yamaha supplied module swapout. Discrete components will be high quality easily replaceable so no problems there, and IMO it is these that will cause most issues not modules laden with SMC's. I know where you're coming from as I love my amp too but if it dies it dies, as one day it will which is when I get the next model up

it wasn’t for that purpose i was think of a second one as a stand in amplifier while my main one was sent of for a service so I would not be without music for ages that’s all I had no intention of using one to rob parts for .

As mentioned above, the amp will 'wear out' even when it isn't being used. In the good old days, you could use a witches brew in electrolytic caps that seemed to last forever. These days, the clean and green electrolytes seem to leak or corrode after a few years. Some of these effects depend on temp, so a hot always-on amp will fry the caps faster than an amp switched off in the cupboard, but they all seem to end up the same way eventually.

 

[drummerman]

If it works doesn't mean it's not broken, as has been demonstrated with recent Cyrus kit.

The achilles heel of amplifiers like all electronics are the electrolytic caps. Good quality Japanese caps should soldier through 10+ years in a Class AB amp with no problem. More heat means less longevity. After 10 years of regular daily use, one should consider general checkup of state of electrolytic caps, cracked solder joints, heat spots and other possible ills. 

Maintanance every 5 years should be simple cleaning dust, cleaning open type switches, relays and potentiometers (closed type not as frequent). Bias and DC offset should be checked and reset if its off. Such process doesn't take more than 1 hour.

Speaker cable and interconnects should be plugged/unplugged once a year to clean oxidation. Cleaning with isopropyl alcohol or specialty sprays is also a good idea. If the speaker cables are bare wire, it's good idea to cut and strip fresh ends say every 2 years. Shouldn't take you more than 5-10 mins. 

Western culture has moved to disposable goods. Cars are bought, abused for 10 years and ditched, typically with no maintanance inbetween. Electronics flood garbage disposal sites. The profession of electronics repair tech has essentially dissapeared. In economies of scale everything is made to survive the warranty period and no more.

Due to this new way of thinking about material goods, I see how my suggestion about maintanance might sound waste of time and pedantic OCD rituals of no benefit. But since the OP asked I thought I'd share my practice.

Ah, the difinitive guide to amplifier servicing

 

[Andrewjvt]

If it works doesn't mean it's not broken, as has been demonstrated with recent Cyrus kit.

The achilles heel of amplifiers like all electronics are the electrolytic caps. Good quality Japanese caps should soldier through 10+ years in a Class AB amp with no problem. More heat means less longevity. After 10 years of regular daily use, one should consider general checkup of state of electrolytic caps, cracked solder joints, heat spots and other possible ills. 

Maintanance every 5 years should be simple cleaning dust, cleaning open type switches, relays and potentiometers (closed type not as frequent). Bias and DC offset should be checked and reset if its off. Such process doesn't take more than 1 hour.

Speaker cable and interconnects should be plugged/unplugged once a year to clean oxidation. Cleaning with isopropyl alcohol or specialty sprays is also a good idea. If the speaker cables are bare wire, it's good idea to cut and strip fresh ends say every 2 years. Shouldn't take you more than 5-10 mins. 

Western culture has moved to disposable goods. Cars are bought, abused for 10 years and ditched, typically with no maintanance inbetween. Electronics flood garbage disposal sites. The profession of electronics repair tech has essentially dissapeared. In economies of scale everything is made to survive the warranty period and no more.

Due to this new way of thinking about material goods, I see how my suggestion about maintanance might sound waste of time and pedantic OCD rituals of no benefit. But since the OP asked I thought I'd share my practice.

When I was a mechanic
I used to repair alternates, starter motors, gearboxes, burnt valves etc

Now days mechanics are fitters of exchanged parts
No more repairs.
I think it's a similar thing what you described regards amps

 

[Gaz37]

But the guy who wrote the quote below has 45 years experience in audio equipment repair

"

[font="Times New Roman, Times, serif"]A particular area of concern covers capacitor replacement. For reasons that defy logic, it is fashionable to replace all of the capacitors in older units. Years ago, there was an equally bizarre fad for changing all of the resistors. This followed on from the routine replacement of valves. We do not replace components for reasons of fashion, (that is all it is). If a capacitor is faulty, then we replace, but if it is not faulty it is better not to disturb the circuit. In some extreme cases, I have found noticeable deterioration resulting from replacing large numbers of capacitors with "better" new ones, with one particular tuner completely ceasing to operate after its owner "replaced all the caps", (that was a very expensive and frustrating repair!).[/font]

 

[andyjm]

If it works doesn't mean it's not broken, as has been demonstrated with recent Cyrus kit.

The achilles heel of amplifiers like all electronics are the electrolytic caps. Good quality Japanese caps should soldier through 10+ years in a Class AB amp with no problem. More heat means less longevity. After 10 years of regular daily use, one should consider general checkup of state of electrolytic caps, cracked solder joints, heat spots and other possible ills.

Maintanance every 5 years should be simple cleaning dust, cleaning open type switches, relays and potentiometers (closed type not as frequent). Bias and DC offset should be checked and reset if its off. Such process doesn't take more than 1 hour.

Speaker cable and interconnects should be plugged/unplugged once a year to clean oxidation. Cleaning with isopropyl alcohol or specialty sprays is also a good idea. If the speaker cables are bare wire, it's good idea to cut and strip fresh ends say every 2 years. Shouldn't take you more than 5-10 mins.

Western culture has moved to disposable goods. Cars are bought, abused for 10 years and ditched, typically with no maintanance inbetween. Electronics flood garbage disposal sites. The profession of electronics repair tech has essentially dissapeared. In economies of scale everything is made to survive the warranty period and no more.

Due to this new way of thinking about material goods, I see how my suggestion about maintanance might sound waste of time and pedantic OCD rituals of no benefit. But since the OP asked I thought I'd share my practice.

Ah, the difinitive guide to amplifier servicing

As anyone who has had a go at repairing electronics will attest, it is extremely difficult to work on modern circuit boards. Surface mount devices are tiny, and component densities on the boards are such that removing and replacing a single component without collateral damage is very difficult indeed. The boards are not designed or built with repair in mind, and frankly throwing a dud board away and replacing it with a new one is by far the best option. If boards aren't available, then I am afraid the device is a toast.

 

[nopiano]

I have never seen a satisfactory answer to this original question. One extreme example is Naim, who routinely and happily replace bits in their amps. But they may be for the generation of amps before the streamers, where they might well have been hand-made along traditional lines, and hence quite easy to ‘service’.

I replaced my almost twenty year old Krell integrated amp earlier this year for fear that something would surely expire soon, or be sub optimal. But it still was quiet and aberration free. It runs quite warm too, being designed long before stand by was an eco thing. This was about keeping circuits warm, to the tune of 30watts of mains plus.

I suspect the few engineers who really know the answer in fact specialise in a few brands, and each will have its quirks. I’m sure your Yamaha will cruise through its first decade, and probably rather longer without a hitch.

 

[Rethep]

When and how often do you service a amplifier and when it’s time for a service where do you send your amplifier for a service in the UK that services probably with good parts if needed .

does Yamaha have a service centre in the UK ?

Are you sure that the uncertainty is in your amp? Maybe you are just not satisfied with your sound anymore.

 

[Blacksabbath25]

I just wondered where you guys take your amplifiers when there is a issue or when you want the amplifier serviced after 10 years or so if any of you keep a amplifier that long .

i am not worried about my amplifier I just wanted to no where’s the best place to take it if there was an issue or for a service after 10 years as I’ve never kept a amplifier as long as I’ve kept my Yamaha before which has only been 16 months so still a baby .

i wasn’t sure if Yamaha had a service centre where I knew it would have the correct parts fitted if needed and the same quality parts that came out of the amplifier put back with the same quality .

but I understand nothing will go wrong yet but you never no and when that time comes I know where to take it in the future .

 

[drummerman]

If it works doesn't mean it's not broken, as has been demonstrated with recent Cyrus kit.

The achilles heel of amplifiers like all electronics are the electrolytic caps. Good quality Japanese caps should soldier through 10+ years in a Class AB amp with no problem. More heat means less longevity. After 10 years of regular daily use, one should consider general checkup of state of electrolytic caps, cracked solder joints, heat spots and other possible ills. 

Maintanance every 5 years should be simple cleaning dust, cleaning open type switches, relays and potentiometers (closed type not as frequent). Bias and DC offset should be checked and reset if its off. Such process doesn't take more than 1 hour.

Speaker cable and interconnects should be plugged/unplugged once a year to clean oxidation. Cleaning with isopropyl alcohol or specialty sprays is also a good idea. If the speaker cables are bare wire, it's good idea to cut and strip fresh ends say every 2 years. Shouldn't take you more than 5-10 mins. 

Western culture has moved to disposable goods. Cars are bought, abused for 10 years and ditched, typically with no maintanance inbetween. Electronics flood garbage disposal sites. The profession of electronics repair tech has essentially dissapeared. In economies of scale everything is made to survive the warranty period and no more.

Due to this new way of thinking about material goods, I see how my suggestion about maintanance might sound waste of time and pedantic OCD rituals of no benefit. But since the OP asked I thought I'd share my practice.

Ah, the difinitive guide to amplifier servicing

As anyone who has had a go at repairing electronics will attest, it is extremely difficult to work on modern circuit boards. Surface mount devices are tiny, and component densities on the boards are such that removing and replacing a single component without collateral damage is very difficult indeed.  The boards are not designed or built with repair in mind, and frankly throwing a dud board away and replacing it with a new one is by far the best option.  If boards aren't available, then I am afraid the device is a toast.

Probably agree. Perhaps also the reason why the likes of Cyrus charge £300 flat fee.

Mind, I managed to repair my SMT Cyrus CD player ... just.

As to servicing, I will repair or have something repaired when there is an audible fault. Why do anything earlier?

Once it reaches that stage I would expect a competent/responsible engineer or company to test all associated components in line and replace them if needed (or, as has been mentioned, replace the board). They will all have original spec repair info. The amp should emerge within reasonably tight tolerance of when it was sold.

Life's to short worrying about something that hasn't happened.

As to Vladimirs suggestion of checking and setting bias ... that may be reasonably straight forward to competent engineer or DIY expert but not so for the average user. Readings have to be taken at intervals, adjustments made several times and things can go badly wrong if not done properly. Much more so than having a gradual tiny and usually inconsequental drift due a slight slide over time.

Best have that done when/if something else goes wrong (likely not because of bias drift)

Imho

 

[Blacksabbath25]

When and how often do you service a amplifier and when it’s time for a service where do you send your amplifier for a service in the UK that services probably with good parts if needed .

does Yamaha have a service centre in the UK ?

Are you sure that the uncertainty is in your amp? Maybe you are just not satisfied with your sound anymore.

I am definitely happy with my sound and amplifier I wouldn’t say no to some Dali epicon 6s but they are £7000 and my wife would kill me I think if I spent that kind of money on speakers I just have to plant the seed in her head so hopefully one day I would have some Dali epicon 6s sitting in my living room..... cross fingers

 

[Vladimir]

I never said after 10 years you should replace all caps and have the amp refurbished. I said a checkup and repairs if needed.

Why is checking the bias current and general inspection important. If the bias has drifted, or a component has failed, or a solder lead is intermittent, it could lead to a transistor or resistor getting overheated. Increased heat kills electrolytic caps sooner than their expected life span. If you catch an issue like this early in the 5 or 10 year checkup, you may prolongue the life of your amp with the need to replace caps much further down the line.

Simple math.

A hypothetical capacitor in the amp is rated 470uF at 35V, 2000 hours at 105C. This means the cap will work for 2000 hours at 105 degree celsius temp. If the ambient temperature in your amp is say 50C, the life span is doubled at 4000h. If you play the amp for 3 hours daily on avg. you will have that cap last 3.65 years every day use. If the ambient temp is lower, the cap is expected to last longer. Good quality Japanese caps will do 10 years easy, 30 even, but its good to make sure they are operating in adequate conditions.

Needless to say, Class A amps will need checkup and service sooner than Class AB and D simply because of the constant heat baking all components inside the amp.

 

[Rethep]

Ok, i understand this is just the beginning ;-) Nice tactics!

I would say there are cheaper speakers which do a good job too! But that requires a new forum subject.

My longest lasting amp was a Harman Kardon, but since 2005 i'm into tubes. Except for the Harman, which went broke after some 15 years of use, and a Cayin with one broken tube which was quickly replaced by the seller, i never had serious issues with my amps. Mostly i sold them to buy something better instead. But the current set still surprises me often with it's beauty, as if it was the 1st time i listened to it. The speakers, some 3500 euro's.

 

[iceman16]

I recommend John Sampson of JS audio repairs. A really nice guy to deal with and he knows his stuff.