What makes the 'frying bacon' sound...

Discussion in 'Amp Central Station' started by King Fan, May 22, 2019.

  1. King Fan

    King Fan Poster Extraordinaire

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    May to August? Sorry for the bump. But although my Vibro Champ seems to remain cured, I recently had this same sound only a good deal worse on a 1955 amp!! A *variable* static. Crackle fizz pause. Crackle crackle crackle fizz pause. Bacon frying!

    Chopsticks, tube swaps; nope. But the noise did lessen some after I had the chassis out of the amp, and it did seem worse with loud notes.

    I tightened the springs on the sockets. Badabing badaboom, the static was gone. So at least I have one first-person answer to my own question.
     
  2. magicfingers99

    magicfingers99 Friend of Leo's

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    bad caps usually give you a hiss, crackles can be bad connections, bad guitar cable. if it smells like bacon, check to see if your amp is kosher..
     
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  3. SecretSquirrel

    SecretSquirrel Friend of Leo's Ad Free Member

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    Very useful discovery!
     
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  4. Mike H.

    Mike H. Tele-Afflicted Silver Supporter

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    My problem with amp crackling turned out to be a speaker voice coil going bad.
    You might try disconnecting the internal speaker and sending the output through another cab.
    If it still crackles, the circuit is the culprit.
     
  5. Skydog1010

    Skydog1010 Tele-Afflicted Platinum Supporter

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    Holding phone or tablet over Strat pickups does get a nice crackle and sizzle going.

    I'm chicken to see if my pacemaker will do it to.

    Called ionization or radiation, bet a trip inside the cap at Chernobyl would really get things popping.
     
  6. charlie chitlin

    charlie chitlin Doctor of Teleocity Silver Supporter

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    I have a couple amps that crackle on start up and have no other symptoms.
    I've learned to ignore it.
     
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  7. peteb

    peteb Friend of Leo's

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    The frying bacon amp sound is meant to differentiate from the run of the mill crackle sound.



    Is this just crackle or is it frying bacon?



    I think the frying bacon sound of amps is noted for its sizzle. That and it is all of the time, not associated with the signal.





    The classic frying bacon sound is supposed to result from old carbon comp plate load resistors that have absorbed moisture over the course of their lives producing the sizzle sound.
     
  8. magicfingers99

    magicfingers99 Friend of Leo's

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    unless you've got a nuclear powered iphone, I doubt its ionizing radiation. its more likely rf interference, cause you got a radio transmitter in your cell phone always pinging cell phone towers to see where the best signal is. Also a wireless TCP/IP transmitter/receiver talking to your WAP, and you've got a bluetooth transmitter/receiver all these devices are blowing rf across different frequency and sometimes using adaptive techniques to change frequencies to increase signa and decrease noise/interference.

    plus whatever crap the nsa/cia and other assorted agencies have mandated to catch the bad guys and everybody else is just collateral damage in their eavesdropping.

    so no plutonium, but you are holding at least a tri-band radio transmitter up against your head every day beaming stuff through your brain and paying nicely for the priveldge of being an unreimbursed medical experiment.

    be sure to make lots of calls today and talk about this with your friends on your personal surviellance device aka cell phone.
     
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  9. Skydog1010

    Skydog1010 Tele-Afflicted Platinum Supporter

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    never hold up to my head.

    my 2.4 - 5Ghz WIFI router tower is in my little bedroom studio.

    My hand wound over wound Alnico 2, 3 and V pups go nutz when I hold them close to my WIFI broadcast tower. Reminds me, I need to move the slow cooker router up on top of my tall bookcase currently it's only about a meter away from my head.
     
  10. LudwigvonBirk

    LudwigvonBirk Tele-Holic

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    Enhancing your Faraday-cage-building expertise a worthy endeavor.
     
  11. Shuster

    Shuster Poster Extraordinaire

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    That would be ME!! When you di*k with my amp settings,,,;)
     
  12. 24 track

    24 track Doctor of Teleocity Silver Supporter

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    I notice some old blue spragues in there, I'd start with a new cap set , then clean and reset the tube contacts , de-Oxit the pots and exercise them and clean the jacks contacts, just maintenance
     
  13. King Fan

    King Fan Poster Extraordinaire

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    I think I've lost the thread in this thread. :)

    If anyone's still talking about my Vibro Champ, the problem has been gone since May. I just updated the thread to say I found a cause (that I don't recall being mentioned in the original thread) in another amp with *serious* 'frying bacon' static, and in *that* amp it was loose springs in the 1955 tube sockets. Hard to believe they'd loosen up in just 64 years, but there you go.

    At this point, let's cue Homer Simpson: "Mmmm, bacon..."
     
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  14. Luthier Vandros

    Luthier Vandros Tele-Holic

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    Plate resistors
     
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  15. King Fan

    King Fan Poster Extraordinaire

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    Hey, it's only been a year! But a weird thing happened after I 'fixed' this. Yes, there was a definite frying bacon sound when I started the thread, and yes, it was gone when I went back to record it.

    But over time, you guessed it, it came back. We all know this, right? Best way to fix a funny noise in your car (temporarily) is to try to demonstrate the noise to a mechanic.

    It wasn't loud, only heard when not playing, so I lived with it. But I thought about it. It was sizzle-y, not just crackle-y. You know how bacon sizzle varies a little from second to second, unlike typical old-radio static? For a long time, I kinda figured it might be the single-strand heater wiring. But does that crackle, or hum, or ???

    Several folks here had suggested old carbon comps, and yeah, this BF VibroChamp is old. But the specific suggestion of old *plate resistors* didn't seem likely here, since some prior mod-man had subbed in odd ?Marshall values for the plate loads, using MF, and thus I had subbed back Fender-value A-B CCs. Yeah, NOS A-Bs, so *old,* but from a biggish batch that have been really quiet everywhere I've used 'em as plate loads.

    But one thing he hadn't subbed, and I hadn't restored, was the 1M input resistor and 68K grid stoppers. And when I finally decided to swap 'em out, although the grid stoppers looked OK, the 1M looked distinctly burnt. Trying to unsolder it, the lead fell out of the burnt looking end.

    IMG_5788.jpeg

    And, FWIW, the tip of the grid lead where it was soldered to the grid stoppers was also dull and brittle and snapped as I got ready to unsolder it. Another possible suspect?

    Anyhow, replaced all three with metal films and trimmed the brittle lead back to clean wire. Result -- this is an insanely quiet amp. So now we know what caused *this* sizzling bacon sound. Hmm, do you smell bacon frying? Mmm, I can almost taste it... :)
     
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  16. BigDaddy23

    BigDaddy23 Tele-Holic

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    Wow. Do you reckon that 1m resistor was cooked in the original installation? You wouldn't expect it to cop destructive in the input. Maybe it was just a QC thing.
     
  17. King Fan

    King Fan Poster Extraordinaire

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    Good question, I wondered the same thing. In an amp that's more than 50 years old, I'm sure anything's possible. The amp had been heavily modded (and heavy-handedly for that matter) at some distant date, so I can't instantly finger the Fender constructor. But that resistor was set professionally down inside the prongs of the jack, with the tail that goes on to the switch bent around to be in front of it as you look -- a pro touch. And that's a possible clue -- you'll see in the pic that placement left almost zero lead length to the joined T/S lugs, which take a little extra heat to solder.

    The fact the noise was occasionally absent makes me wonder about a crack in either that lead or the grid lead that was soldered to the joined grid stoppers. As I say, both broke right off during unsoldering.
     
  18. LudwigvonBirk

    LudwigvonBirk Tele-Holic

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    KF, good sleuthing and commentary as always.

    Other than being “vintage correct”, I don’t think anything other than ultra-quiet (e.g., metal film) resistors should be used at the input jacks. As you know there’s arguably a place for hissy-with-heat carbon comps in specific spots if you really want that and can hear it, but putting anything hissy pre-V1...that’s like skiing deep powder with ‘69-‘72 Look bindings (sure you can, but why)
     
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  19. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    Cool to hear "the rest of the story!" Wonder if just inserting the plug jostled the resistor into making better contact sometimes...
     
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  20. King Fan

    King Fan Poster Extraordinaire

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    Thanks, LVB. Were those the famous 'Long Thongs"? They'd break your leg in a heartbeat, but they looked really cool with the entire boot and leg wrapped to the knee in thick red leather straps...

    You're so right. Cracked solder joints, leads, wires, even components seem to lie at the end of quite a few 'intermittent fault' stories. Sadly, this one was only intermittent when I tried to track it down...
     
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