Cab vibration vs amp electronics

Those of us who design quality amplifiers have put a lot of thought and effort into the mechanical aspects of our respective products, and vibration is generally not an issue over decades of use.

 

The air around the amp head vibrates far more than the cabinet, especially if you have one of those "drummer" thingies.

 

Just have your old lady ( or your date) sit on top of your cab and hold the amp. .
That way , she gets ready for the show after the show and your amp stays safe

 

Yes, one time the female keyboard player in my band sat on my cabinet, I hit the third fret on my E string, and you could say we found the ‘G’ spot.

 

Cabs shouldn’t vibrate to that degree. If yours does, then you can add additional bracing, which may have been omitted at the factory for cost reasons.

 

My Dad was a Ham Operator, and at the suggestion of one of his fellow Hams, who was also a knowledgeable linear tube amp tech, I started placing a sheet of thick foam between my amp and the cabinet it's on top of.

It became a habit, so I continued doing this when I started running solid state power about 15 years ago.

My guess is most quality amps are built to handle the rigors of transport and vibration, but to satisfy my OCD, - or being the worrywart type, I'll keep doing it anyway.

 

If you're talking Solid-State amp/head there is no problems.
Amp module makers actually shake test the modules. The modules are often built into powered cabinets.

 

This

 

If you are using one of these it might be advisable

 

Your general question regarding long term reliability effects of cabinet vibrations on amplifier electronic integrity is not an entirely simple question to answer. The simple, but probably somewhat misleading answer would be no; at least I am not aware of any MI amplifier manufacturer doing any significant reliability tests with the finished amplifier on a system such as this one:
Labworks Inc.- dLW140.153-CTS CubeSat Test Station

@agedhorse can correct me if I am wrong; but I don’t believe any MI amp manufacturers put their amps through exhaustive long term testing on a controlled test bed like that referenced above.

What does happen is that the board level assembly plants which perform solder reflow on the surface mount components do perform that kind of work as required to obtain various certification levels. To what extent such certified processes are or are not contracted explicitly in Bass amp board level sourcing is unknown. But, most likely, whether the boards themselves have such qualification or not, they are likely to benefit as ancillary products in the more general spectrum of the technology. Hope that makes sense.

My $0.019 experience over the years where I’ve seen issues with cab vibration getting to the head include the power tubes in the several Bassman amp heads I gigged way back when; and then mostly stuff tending to fall off the amp during the set; picks, tuners, beers etc. Preamp tubes have never seemed to be an issue, which is kind of interesting. I did have several A/B hybrids fail back in the 90’s, including a favored Eden VT.25; but, I didn’t really do any failure analysis at the time. Solder wave and surface mount technology has most definitely made the boards more reliable, again IME.

All that said, each of us needs to decide what we are comfortable with. I’m not comfortable just putting a $1k amp head directly on a driven cab night after night; and though I wouldn’t call it OCD, I’ve put some kind of pad beneath my amps for the past 10 years or so. I mean, you can go spend $20 down at the hardware store to protect a $1k amp. Tool drawer liner (double it up) or garden kneeling pads both work, and are readily available. Plus, putting a pad beneath your amp may just keep it from rattling off the top surface of the amp, depending on how prone the amp may be to sliding. Pretty minimal investment with a lot of upside and not much downside; but, YMMV.

Oh, and cabinets do vibrate. Even the well braced ones.

 

Agedhorse did address this already. .

 

Well made circuitry should last for a while. However, a bass player I know had a Peavey combo amp (this is a few decades ago) that I replaced 2 power electrolytics, an inductor and a high power resistor after they all vibrated themselves to the point of breaking a lead - after a few of these failures, I RTV'd everything I could in place, and it helped. I myself had a Yamaha solid state amp where a driver transistor broke a lead - I managed to shorten the leads, reinsert the transistor, glue it down, and it worked for years afterwards. A lot of folks used to take apart electronics and RTV in place anything that looked like it might vibrate before going on tours. That may have been mostly to protect against truck vibrations, but the principle is the same. Vibration can cause failures - I've seen a few.

I used to carry some foam blocks that I used to "float" my amplifier head on top of the speaker cabinets I had. That amp never had vibration issues. Nowadays, the one gig I play with an amp, the amp is not on top of the speaker - it's on the floor in front of me, tipped back as a monitor - just part of how that gig layout is.

 

I think most electronics will long outlive the owner.

 

that sounds like the plot of a horror movie

 

The only surface mount technology we use is within the IcePower module and is designed, tested and fully qualified with respect to vibration and impact.

Otherwise just about everything I design uses through-hole technology, the PCB holes are plated, the axial/radial leads are clenched and the heavy components also glued to the board. This type of construction has well documented reliability metrics over decades of use in our industry.

 

Your head will feel worse vibrations from the car ride to and fro, the walking thumping impact of your feet while carrying it in and out than from setting it on top of a cab playing it.

Unless you pull it off that cab with a cable.

Just play, you are good.

 

Here's my hard earned data... for a long time I was running a GK1001RB into a Mesa 6x10. It BLASTED. And it shook more than just the room. One day my robust ol' GK suddenly craps out on me. Bring it to a shop, turns out the vibrations had loosened a screw and dropped it right in the middle of the circuit board!

 

I've got a stack that's about 35 years old (it was getting on for a decade old when I bought it).

Some years it's been gigged ridiculously hard.

Some years it hasn't been gigged at all.

Some years it's been gigged regularly.

It's never once had any issues.

So long as it's quality equipment to begin with, I wouldn't worry about it (but no harm in placing the head away from the cabinets - it's just not very convenient, when you need to make on the fly adjustments, and the preamp isn't at eye level, with you in direct earshot of the speakers).