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What causes a solid state amp to deteriorate/fail over time?

Discussion in 'Amps and Cabs [BG]' started by Diesel Kilgore, Dec 29, 2012.

  1. Its a piece of low budget junk to begin with. And I bought it used. Drive 30w combo. But for the first 3 months I had it, it was fine, had nice volume, all the eq settings worked well. Its the reason I bought it, it was cheap and performed.

    Then one day it starts farting and seemingly in some cases gets muffled like it cant pickup the proper signal from the bass. If I turn up the bass and mid controls it will fart. If I keep them low its okay. But then the quality I want isnt there.

    I took it apart today to see if something was loose or corroded or dirty. No problems.

    Its probably going in the trash soon as soon as I get my other rig paired up with a head. But I am curious as to what factors cause an amp to start doing this? Maybe the tone and volume pots failing?
  2. john m

    john m Supporting Member

    Jan 15, 2006
    Speaker is shot
  3. TIME and use/non-use/abuse. Could be caps failing, controls dirty, jacks dirty, speaker failing, junctions in semi conductors failing. Why do lamp bulbs burn out? Why do I get older EVERY darn year :D
  4. tmdazed


    Sep 29, 2012
    Components have a finite duty cycle, Caps dry out (most common) Diodes pop, transistors give it up, nothing lasts forever, even worse now with indonesian and Vietnamese made caps and semiconductors, they are not making them with heat range tolerances like they once did.
  5. januchito


    Aug 15, 2009
    Santiago, Chile
    well, you have 3 posibilities


    The speaker faill. The speaker can fail one side for the coil, don have the resistance need (8 ohm) if have minus... the amp fail, over all is 3 or less ohm. Another fail is the cone is perfored, you can chek easey, visualy. in bouth caes, the better is replace


    The electrolitic capacitor of the power supply is in short circuit or lost acid. if is in short circuit the fusible is burn. If is the lost acid, the amp sound fine for some minutos, arround 5 or 10, and start to ear a noisse very bothersome. If you try, change the condenser, dont have repair.


    Te some potenciometer is faill, in any moment can star the noisse, and stop if you only touch the knob. Te solucion is change.

    The three opcion, happen for natural use amp. The capacitor (in any amp, included the top line in any desing and building) have a limited life, and is more long or not, if the electrical net is stable, the static, the temperature ambiental, etc etc...

    Te potenciometer have mechanical component, whit fisical touch, and whit use, this fail.

    that is natural.
  6. Thanks guys. I feel better now. I was bummed cause I only had the thing 6 months. The amp itself is what? 5 years old. Oh well. It was cheap to buy them new and there was a reason for it. The plus side is that it has some cool chicken head knobs that I am going to pull off and re-use before I trash it. :D
  7. f64


    Oct 31, 2009
    Everything that's been mentioned should be investigated. They are all good suggestions.
    Ever wonder why cell phones die unexpectedly? Amps are subject to the same problems due to age and thermal shocking. Here is something else to ponder:


    This lately is the main reason I steer towards tube amps.
  8. 1958Bassman


    Oct 20, 2007
    Can you try a different speaker? The pots shouldn't have failed so soon. I would suspect many other things before those.

    Electronic components fail mostly due to heat. A speaker that has a shorted voice coil winding makes the amp's output devices handle more current than they were designed for and that cooks them. If it has been "rode hard & put away wet", that will kill an amp, too. A loose jack or something causing a short at the jack(s) will do it.