Cab vibration vs amp electronics

Discussion in 'Amps and Cabs [BG]' started by Cazman, Jun 16, 2019.

  1. Cazman

    Cazman Motorboatin' Supporting Member

    May 9, 2003
    Coastal SoCal
    I posted in another thread but throwing it out to general population....
    Is there any data ( or long term study) on the effect of vibration from the cab to amp on the electronics longevity?
    Seeing most of us stack our heads on top of the cab, I was wondering what (if any) steps are taken in manufacturing to minimize vibration effects on the amp circuitry.
    Vibrations should eventually loosen solder joints, connections, and rattle components, so might we all be better off placing our amp heads separated from the cab, whether next to it or on a dampening pad?.... just thinking out loud.
    Ellery likes this.
  2. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    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.
    Maluku, Jesuguru, GrapeBass and 15 others like this.
  3. Mingo Sanders

    Mingo Sanders

    Mar 11, 2008
    Austin, TX
    The air around the amp head vibrates far more than the cabinet, especially if you have one of those "drummer" thingies.
    DrThumpenstein, Ekulati and TubeDood like this.
  4. TubeDood

    TubeDood Inactive

    May 31, 2019
    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 ;)
  5. Michedelic

    Michedelic MId-Century Modern

    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.
    Ekulati, MuttThud, Goatrope and 2 others like this.
  6. ctmullins

    ctmullins Dominated Gold Supporting Member

    Apr 18, 2008
    MS Gulf Coast
    I'm highly opinionated and extremely self-assured
    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. :mad:
    BrBss likes this.
  7. Arthur U. Poon

    Arthur U. Poon

    Jan 30, 2004
    SLC, Utah -USA-
    Endorsing Artist: Mike Lull Custom Basses
    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. :D
    Last edited: Jun 17, 2019
    eldorado2001 and fat4 like this.
  8. 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.
    Arthur U. Poon likes this.
  9. jlepre


    Nov 12, 2007
    Cedar Knolls, NJ
  10. Edword


    Jun 23, 2005
    If you are using one of these it might be advisable

    Last edited: Jun 17, 2019
  11. bucephylus

    bucephylus Supporting Member

    Aug 18, 2002
    Central Ohio
    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.
    Maluku and Arthur U. Poon like this.
  12. TubeDood

    TubeDood Inactive

    May 31, 2019
    Agedhorse did address this already. .
  13. micguy


    May 17, 2011
    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.
    Last edited: Jun 17, 2019
    Arthur U. Poon likes this.
  14. seilerbird


    Apr 12, 2012
    I think most electronics will long outlive the owner.
  15. sears

    sears Supporting Member

    Aug 7, 2005
    ec, md
    that sounds like the plot of a horror movie
    Epitaph04 and kobass like this.
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    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.
  17. Cazman

    Cazman Motorboatin' Supporting Member

    May 9, 2003
    Coastal SoCal
    Here is the response I got from Jeff Genzler, whose rig I currently run....

    ...”This is a good question and something you don't hear very often. AND it is something we feel we've addressed with a few different design elements within the Magellan 350 and 800 designs. I'll say going back many years, you can actually make an amp that is "too lite" which could create more vibrations as the amp sat on a high output cabinet. The issue of amps vibrating off the cabinet was an experience that many players had to address ---- thus the damping pads, etc. When developing our Magellan amps we addressed this with a solid alum chassis which helped to provide a little more "heft" to the amp's weight AND the all important soft rubber feet we use that work somewhat provide some shock-mount characteristics that dampen vibrations from the top of the speaker cabinet. Even though the MG-800 is lite (6 lbs) we feel it has enough weight and heft to hold it onto any cabinet and the rubber feet help in eliminating vibrations inside the chassis. Another point in how we address these concerns is internal in the chassis as it relates to wire harnesses. All harnesses are held in place with tie-down points so that no harness is "flopping around" where it could come loose in transit or vibration. As for components vibrating loose, I don't think it today's amp designs, you'd have that much of a concern. Certainly nothing we've seen in real world use.

    Overall I would say with the Magellan designs you would have no concerns with vibration related issues. Certainly if you feel more comfortable with some sort of a vibration mat between the amp and cabinet, it is not going to hurt anything for that peace of mind, for you. Hope this is helpful.”
    Al Kraft and agedhorse like this.
  18. 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. :eek:

    Just play, you are good.
    seamonkey likes this.
  19. Ellery


    Mar 25, 2015
    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!
    Arthur U. Poon and Marhmol like this.
  20. Wood and Wire

    Wood and Wire

    Jul 15, 2017
    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).