Amp Maintenance DIY

[fdeck]

I'm qualified to do it, but have had remarkably few amp problems requiring service. And I wouldn't know where to begin with the modern stuff unless it's something easy like a broken switch. I've fixed basses, and recently re-glued a seam on my cello. I've also fixed home appliances.

I've repaired cables.

I think that the lighter, smaller gear tends to get less abuse because it doesn't get knocked around as much. For instance my amp head goes into a small backpack when I'm done with a gig, and doesn't come out until the next gig. I load and transport all of my gear myself. So it lives a pretty cushy life.

 

[BassNugget]

I drain and refill the transformer oil every 50,000 quarter-notes or so... more often if I'm playing a lot of heavy metal. I usually rotate the casters at the same time, whether they need it or not. Hope this helps.

Yes yes, but how do you drain, filter, and replace the magic smoke? Or is that a sealed chassis?

 

[larrysb]

Well, as a electronics engineer, who worked through high school and college as an electronics technician in a variety of industries, including musical equipment, yes, I maintain my own equipment.

Solid state bass amps need little care, other than cleaning the dust out and cleaning the controls and jacks every so often. Mostly, if it ain't broke, don't fix it.

Tube gear is a bit different and needs more ongoing care. But, be aware, they do have lethal voltages inside. An SVT or a 400-PS can deal you a deadly (not kidding) shock.

 

[BoogieZK]

Unless you know exactly what you are doing and have the tools to do this, leave it alone or learn how to do it right.

I see a fair amount of damage from folks trying to do this themselves following abysmal internet advice and even even worse YouTube videos, ending up with expensive repairs (and even unrepairable or uneconomical to repair amps)

For example, the guy who blew compressed air into the fan, spun it way up and damaged the fan control circuit. Or, the guy vacuuming dust off a PCB damaging a surface mount component cap he hit with the end of the hose.

Not only this, but the fan can fly apart and cause injury if spun up to too high a speed with compressed air.

Vacuum cleaners are great electrostatic generators and can damage solid state components on PC boards.

Common sense guys?
When you wash your sensitive areas, do you use a high pressure water cleaner or 60grit sandpaper?

Yes, do maintenance with caution and good sense.
Soft brushes, isolated screwdrivers, a working and good voltmeter, adapted size tools.... Common sense right?
Or is it this hard?

 

[agedhorse]

I have actually wondered why dust filters aren't a feature on the higher end amps, good computers have them and they can't be more than a few bucks to implement. Getting users to clean them would be a different story

The pressure drop across a filter requires a lot more fan power for a given CFM. This can greatly increase the noise level, especially for the smaller diameter fans.

Common sense guys?
When you wash your sensitive areas, do you use a high pressure water cleaner or 60grit sandpaper?

Yes, do maintenance with caution and good sense.
Soft brushes, isolated screwdrivers, a working and good voltmeter, adapted size tools.... Common sense right?
Or is it this hard?

Clearly, you don't know anyone who works in an ER. You might be surprised at how little common sense some folks have.

I see it sometimes in amps returned for service too, some scary looking stuff.

 

[JakobT]

Hello there,

Do you guys and gals, do your regular amplifier maintenance by yourself? If so, what do you do and how often?


Thank You!

Yes, I dust mine every week or so.

 

[BoogieZK]

The pressure drop across a filter requires a lot more fan power for a given CFM. This can greatly increase the noise level, especially for the smaller diameter fans.
Clearly, you don't know anyone who works in an ER. You might be surprised at how little common sense some folks have.
I see it sometimes in amps returned for service too, some scary looking stuff.

No I do, i work in many type of industries including customers service for car maintenance products... And yeah i've seen some eyes-ripping stuff.
Still I work in satellites and clearly gear is abused and raped every day....
I just have some rest of hope that people who bought expensive gear and who try take care by themself of this gear will not go BAAAAZOOOOOKKAAAAA inside of it, just because!
I mean come on.

 

[Sparky Mark]

Many, many years ago, for some reason I can't remember, I attempted to adjust the bias on my Hartke AH3500. A minute turn of a relevant trim pot resulted in a trip to the nearest amp tech and a not insignificant bill; lesson learnt.

 

[chris_b]

I switch my amps on and off. That's it. I'm a bass player not an amp guy.

In my life I've had 2 amps fail and they went back to the repair shop. I've had no issues/problems since switching to SS and D class amps. These things are as reliable as I could wish for.

 

[Sparky Mark]

I switch my amps on and off. That's it. I'm a bass player not an amp guy.

In my life I've had 2 amps fail and they went back to the repair shop. I've had no issues/problems since switching to SS and D class amps. These things are as reliable as I could wish for.

Strangely in 45 years of playing, the only amp that ever failed me was Class D. The failure was nothing to do with topology, it had a fractured solder joint on an output connection.

 

[dbase]

I change the pots and caps on a regular basis just for gigglies.

 

[40Hz]

Other than basic cosmetic care, I otherwise leave my amps alone. And I haven't experienced any issues other than a tube needing replacement.

With preamp tubes I just replace them with the same tube. If a power tube or something else looks iffy, I'll send it (along with any replacement tubes I want to use) over to my tech and let him check it out and/or handle the re-biasing should tubes need replacing. He appreciates the business. And I have more profitable uses of my time than ditzing around with circuitry I don't fully understand.

My background is in digital electronics and IT. If there's an electronic or other issue with a datalink, a server, or a network switch, I'm in my home element. And I and have the tools and the know how to troubleshoot and fix it. Anything else, beyond basic electrical wiring or data cabling, I leave to other professionals. And I've never regretted it.

 

[agedhorse]

Other than basic cosmetic care, I otherwise leave my amps alone. And I haven't experienced any issues other than a tube needing replacement.

With preamp tubes I just replace them with the same tube. If a power tube or something else looks iffy, I'll send it (along with any replacement tubes I want to use) over to my tech and let him check it out and/or handle the re-biasing should tubes need replacing. He appreciates the business. And I have more profitable uses of my time than ditzing around with circuitry I don't fully understand.

My background is in digital electronics and IT. If there's an electronic or other issue with a datalink, a server, or a network switch, I'm in my home element. And I and have the tools and the know how to troubleshoot and fix it. Anything else, beyond basic electrical wiring or data cabling, I leave to other professionals. And I've never regretted it.

Likewise, many folks create their own unique are creative problems messing with their computers and network settings, well beyond their pay grade…

 

[40Hz]

Likewise, many folks create their own unique are creative problems messing with their computers and network settings, well beyond their pay grade…

Occasionally. But due to the extreme modular construction of data systems which are, by design, fairly easy to troubleshoot and repair compared to many other systems since zero downtime is pretty much the industry standard for IT, there's considerably less risk for a moderately knowledgeable amateur to open the hood compared to more monolithic audio systems.

Software and operating systems are a different matter. But not most electronics found in data systems. You don't encounter the varying border states (good, suboptimal, less good, even less good…etc.) you see with analog electronics. I think that, when combined with the potentially lethal current and voltages found inside many guitar amps, makes troubleshooting and repairing a guitar amp far more challenging and demanding of experience and expertise. Piking around willy-nilly inside a network switch may fry the switch. But it's highly unlikely you'll ever be electrocuted. Worse thing that might happen to you is losing your job if you did something exceptionally stupid and irresponsible.

Besides, with digital there are only two states you need to deal with. On or Off. (Works or Doesn'tWork.) There's little "art" involved in IT triage. Once you identify the symptoms, that resolves to a few areas that could cause that symptom. After that you know exactly what needs to be fixed. It's pretty cut and dried. You can even flowchart it and walk someone with a little experience and training through it over the phone if necessary.

 

[Dave TB Killer]

I actually did open up an old Peavey head once and sprayed out the inside with Windex. Rinsed off with water in the bath tub, let dry in the sun for a day. Put it all back together and it worked fine, after the initial first few jolts of current arched across my strings. Just kidding about the shock.

 

[byacey]

Common sense guys?
When you wash your sensitive areas, do you use a high pressure water cleaner or 60grit sandpaper?

Yes, do maintenance with caution and good sense.
Soft brushes, isolated screwdrivers, a working and good voltmeter, adapted size tools.... Common sense right?
Or is it this hard?

For someone accredited with a degree in electronics and years of experience of working on gear it may be common sense and beyond any discussion, but this thread is directed towards those that don't have any formal training or understanding.

Before the cover is even removed, there is a potential for damage or injury to occur due to lack of knowledge and training, no matter how much care and attention is exercised. To encourage people to do so will potentially create more damage than good, compared to leaving it alone if it's working as it should.

 

[Redbrangus]

It been my experience that common sense isn't all that common.

 

[Andy Marshman]

As a qualified amp tech, I only do 'as required' maintenance. Cleaning dirty jacks and pots is the most common thing I have needed to do (for quite some time). If I pick up used gear, I do those steps right away. For tube amps, I check the bias (and usually set it a bit 'hot' for my tone tastes). My advice to anyone is to take your amp to a qualified tech if you have any problems.
My friend, a guitar player with many years of experience, plays through his PA system directly. His son gave him a nice Orange combo amp, about 25 Watts for at home practice and convenience. He asked me to check out an awful noise. It turned out that he had the gain and volume cranked to max. No fault, just turn those dials to sensible settings (even for distortions). Imagine if he decided to go into his own amp?

 

[Liko]

Hello there,

Do you guys and gals, do your regular amplifier maintenance by yourself? If so, what do you do and how often?


Thank You!

Only amp I've had that ever needed fixing was an old Lab Series L6. Plugged it straight into the wall, and a power surge blew a transistor. That was far beyond my ability to diagnose and fix at the time (these days the problem would be time and patience).

Beyond that, about the only thing I do in the amp maintenance vein is clean scratchy pots and dust off panels and speaker cones.

 

[BoogieZK]

For someone accredited with a degree in electronics and years of experience of working on gear it may be common sense and beyond any discussion, but this thread is directed towards those that don't have any formal training or understanding.

Before the cover is even removed, there is a potential for damage or injury to occur due to lack of knowledge and training, no matter how much care and attention is exercised. To encourage people to do so will potentially create more damage than good, compared to leaving it alone if it's working as it should.

I think if the question is asked we're talking about people without formal training or understanding of electronics but who throw some interest into keeping an amp working well.
I prefer encouraging curiosity, open-mind and pursuit of knowledge.

Phone or go to your local electronic shop, they will answer gladly what to do and what not to do.