Results 1 to 19 of 19

Thread: 5F2A rustling noise

  1. #1
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    5F2A rustling noise

    I have a rustling type noise when the amp first fires up and then periodically thereafter. Not really affected by the guitar, cable, or volume or tone controls so I am assuming the output stage.

    Any ideas on what to try and/or look at?

    I replaced the copper cap with a NOS Tung-Sol 5Y3 and replaced both pre-amp and power tubes so I don't think its tubes.

    thanks!



    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  2. #2
    Forum Member NTBluesGuitar's Avatar
    Join Date
    Apr 2006
    Location
    North Texas
    Posts
    5,820

    Re: 5F2A rustling noise

    Static or some other external interference, perhaps?

    Does it matter if the guitar is plugged in or not?
    "...pray do not imagine that those who make the noise are the only inhabitants of the field;
    that, of course, they are many in number; or that, after all, they are other than the little,
    shriveled, meagre, hopping, though loud and troublesome, insects of the hour."

    -Edmund Burke

  3. #3
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    It does it even with the cable unplugged.


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  4. #4
    Forum Member
    Join Date
    May 2008
    Posts
    616

    Re: 5F2A rustling noise

    preamp tube noise, replace it.

  5. #5
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    Quote Originally Posted by steve25 View Post
    preamp tube noise, replace it.
    I have had 3 different new tubes in there and same thing (1 new EH and 2 new JJ)...

    maybe one of the socket pins or solder joints?


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  6. #6
    Forum Member
    Join Date
    May 2008
    Posts
    608

    Re: 5F2A rustling noise

    Pull v1 and fire up the amp. Is the noise there? If it is Pull v2. Is the noise there?

    It could be cold solder joint or a tube socket isn't tight enough, or just a bad preamp tube.

  7. #7
    Forum Member Toneseeker's Avatar
    Join Date
    Oct 2007
    Location
    Bo'ness, Scotland
    Posts
    496

    Re: 5F2A rustling noise

    I had something similar with my 5F6A. Kinda like a crackly cable. I Resoldered all the joints around the Smoothing Caps. That fixed it.
    Might be worth a try.

    Pete
    Failure is simply the opportunity to begin again, this time more intelligently.

    Henry Ford

  8. #8
    Forum Member
    Join Date
    May 2008
    Posts
    616

    Re: 5F2A rustling noise

    Change out all the preamp tube plate load resistors then.

  9. #9
    Forum Member
    Join Date
    May 2008
    Posts
    608

    Re: 5F2A rustling noise

    That's a good call too. Are they carbon comps? Don't believe the hype, carbon film (or better yet metal films) for this purpose are just fine.

  10. #10
    Forum Member Gris's Avatar
    Join Date
    Dec 2005
    Location
    Tourin the southland in a travelin minstrel show...
    Posts
    2,916

    Re: 5F2A rustling noise

    Don't sweat it. That is just the sound of Tone-rangers rustling up tone-doggies on their way to the tone-down. It will still sound great after a few minutes when they get to the tone-rodeo and everything gets cranked up.

    Yup, it's Friday night already, hic ... :-)

  11. #11
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    Quote Originally Posted by CJ Neel View Post
    That's a good call too. Are they carbon comps? Don't believe the hype, carbon film (or better yet metal films) for this purpose are just fine.
    All Xicon metal film.

    I am going to open her up today and start tapping with my chopstick.

    Its defintely not a tube - I have had a dozen in there now. And there is only a V1 on a Princeton - no V2. Just one pre-amp, one power and one rectifier.


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  12. #12
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    Quote Originally Posted by Toneseeker View Post
    I had something similar with my 5F6A. Kinda like a crackly cable. I Resoldered all the joints around the Smoothing Caps. That fixed it.
    Might be worth a try.

    Pete
    Thanks. Which capacitors are the"smoothing caps" ?


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  13. #13
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    you mean filter caps right?


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  14. #14
    Forum Member Cygnus X1's Avatar
    Join Date
    Aug 2007
    Location
    Sunny South Carolina
    Posts
    2,949

    Re: 5F2A rustling noise

    Wouldn't tone and coupling caps be a suspect also?

  15. #15
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    OK - so this was weird.

    I took off the rear cover and plugged in the amp. I used my chopstick probe to start tapping things, and all of the wiring was VERY microphonic. A tap on any of the pre-amp wiring, tone control, volume control wiring etc. was clearly heard through the speaker as if I was touching the windscreen on a mic.

    So I started looking at the inner input jack and the resistor there.

    As I moved my hand closer to that area - the hum got CRAZY loud (this is with the amp cranked up and no cable connected).

    I then moved the resistor slightly and the amp went silent.

    I thought maybe it was dead - but I plugged in a cable and the amp is now just DEAD silent. I have never had a tube amp this quiet before.

    Crazy.

    I am going to reflow the solder in the input area after draining the caps and then hope that it stays this way.

    I assume I had some sort of incidental contact and a ground issue as the hum induced by the proximity of my hand also went away if I touched the chassis.

    Any ideas?


    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

  16. #16
    Forum Member NTBluesGuitar's Avatar
    Join Date
    Apr 2006
    Location
    North Texas
    Posts
    5,820

    Re: 5F2A rustling noise

    Could have been a cold joint on that resistor, and it could be some static from your hand or something that grounded when you touched the chassis.

    But hey, it's healthy now, right?
    "...pray do not imagine that those who make the noise are the only inhabitants of the field;
    that, of course, they are many in number; or that, after all, they are other than the little,
    shriveled, meagre, hopping, though loud and troublesome, insects of the hour."

    -Edmund Burke

  17. #17
    Forum Member
    Join Date
    May 2008
    Posts
    616

    Re: 5F2A rustling noise

    Pull the first preamp tube out, if the problem is still going on then its not in the preamp stages, but maybe the PI.
    Also those 68k resistors on the input jack could be noisy, so short the tube side of the input to ground and see if the noise stops.

  18. #18
    Forum Member
    Join Date
    May 2008
    Posts
    616

    Re: 5F2A rustling noise

    Sorry, you only have one preamp tube, so shorting across the 100k plate load resistors one at a time will let you kill the gain of that stage and pin down if its from one or the others componets.

  19. #19
    Forum Member sting7777's Avatar
    Join Date
    Jul 2007
    Posts
    695

    Re: 5F2A rustling noise

    Yep - having just one pre-amp tube makes troubleshooting a bit easier.

    I ended up just reflowing and touching up any solder joint I could get to as well as re-wiring the input jacks just to make sure. Its amazing what you can "fix" when you revisit a project. When I originally built this amp I thought I did a great job, but every time I open it up I see an opportunity to make something neater, cleaner, etc.

    Noise is gone so far. Keeping my fingers crossed.



    "Oh, Mister D.J.,
    I keep wondering why you don't play much blues anymore
    I don't know what you got against me
    Whatever it is, I sure would like to know"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •