Follow us on...
Follow us on Twitter Follow us on Facebook Watch us on YouTube
Register
Results 1 to 7 of 7

Thread: 5150 ii problem

  1. #1
    Top Of The World
    Join Date
    10.22.07
    Posts
    214
    Last Online

    12.14.09 @ 03:10 PM
    Likes
    0
    Liked 0 Times in 0 Posts

    Default 5150 ii problem

    Ok, so I had a show on friday and the amp sounded great. I got it home and set it up, and I turned it on. I let the tubes warm up for a couple minuets and I turned it on. For some reason it wouldn't get louder and it sounded extremly thin. I then took off the tube covers and I made sure they were all in correctly. Now the amp works and gets louder but it seems my tone has suffered. I want to know if I should focus on the power tubes or the preamp tubes for this problem. I tapped on them to see if one was more microphonic then the other but they seemed fine. I am going to replace V1 with my sylvania 12ax7 and see if it does anything. If anybody has advice or help I would greatly appriciate it.

  2. #2
    Good Enough nobozos's Avatar
    Join Date
    02.16.00
    Location
    Pekin, Il U.S.A.
    Posts
    1,745
    Last Online

    12.12.17 @ 03:16 PM
    Likes
    22
    Liked 724 Times in 341 Posts

    Default

    Here's a couple things I would recommend:

    First off, pull each tube from the socket and re-plug it in. Somtimes a simple re-seat of the pins is all that is needed. The pins on the tubes are small, and can be jostled loose during transportation. Also, you can get minor corrosion on the pins that will interfere with the free flow of electrons from the socket to the tube. Re-seating the tube will "scrub" off the corrosion and give you a clean mating surface if that is the case.

    Secondly, it was my experience with my 5150 combo that the amp eats pre-amp tubes for breakfast. I was replacing them every 6 months when I was gigging regularly. The biggest problems I experienced were a loss of gain, and microphonic tubes. JJ's were the best overall for tone and reliability. Ei's were great for tone, but failed more quickly.

    If you re-seat your tubes, and still have a problem, I would recommend replacing the pre-amp tubes, and see if that corrects the problem. They are relatively inexpensive, and do not require biasing. If that doesn't fix it, take your amp into a reputable repair shop and have them change the power tubes. Don't get Groove Tubes, and don't let anyone talk you into them. They may work in other amps, but sound like crap in a 5150.

    Hope this helps.
    "Having an opinion that people disagree with doesn't make you a Douche, arguing with the people who disagree with your opinion and calling them stupid does!" -Me.

  3. #3
    Top Of The World
    Join Date
    10.22.07
    Posts
    214
    Last Online

    12.14.09 @ 03:10 PM
    Likes
    0
    Liked 0 Times in 0 Posts

    Default

    Quote Originally Posted by nobozos View Post
    Here's a couple things I would recommend:

    First off, pull each tube from the socket and re-plug it in. Somtimes a simple re-seat of the pins is all that is needed. The pins on the tubes are small, and can be jostled loose during transportation. Also, you can get minor corrosion on the pins that will interfere with the free flow of electrons from the socket to the tube. Re-seating the tube will "scrub" off the corrosion and give you a clean mating surface if that is the case.

    Secondly, it was my experience with my 5150 combo that the amp eats pre-amp tubes for breakfast. I was replacing them every 6 months when I was gigging regularly. The biggest problems I experienced were a loss of gain, and microphonic tubes. JJ's were the best overall for tone and reliability. Ei's were great for tone, but failed more quickly.

    If you re-seat your tubes, and still have a problem, I would recommend replacing the pre-amp tubes, and see if that corrects the problem. They are relatively inexpensive, and do not require biasing. If that doesn't fix it, take your amp into a reputable repair shop and have them change the power tubes. Don't get Groove Tubes, and don't let anyone talk you into them. They may work in other amps, but sound like crap in a 5150.

    Hope this helps.
    Thank you for the help! I have JJ's in there right now but I replaced V1 with a NOS sylvania. I think I will try to reseat all of the tubes. If that doesn't work I will retube it. It doesn't do the loudness problem anymore but the tone doesn't sound as good.

  4. #4
    Forum Frontman
    Join Date
    09.15.06
    Age
    42
    Location
    Minneapolis
    Posts
    6,568
    Last Online

    07.04.16 @ 08:03 PM
    Likes
    3
    Liked 6 Times in 5 Posts

    Default

    I'm sorry there hasn't been much more help posted here. I'm at a loss when it comes to amp repairs beyond just checking all the connections and keeping things clean.

    The only thing I can add to the above post would be to clean the tube sockets with a small amount of electrical contact cleaner. It shouldn't harm the electronics and will help clean out gunk. I think the idea is: If you were somewhere playing your amp and it sounded great, then you moved it and it sounded like crap, there's some "disconnect" in it now. Perhaps it's just one tube not making contact correctly.

  5. #5
    Top Of The World
    Join Date
    10.22.07
    Posts
    214
    Last Online

    12.14.09 @ 03:10 PM
    Likes
    0
    Liked 0 Times in 0 Posts

    Default

    Quote Originally Posted by AndrewThomas.net View Post
    I'm sorry there hasn't been much more help posted here. I'm at a loss when it comes to amp repairs beyond just checking all the connections and keeping things clean.

    The only thing I can add to the above post would be to clean the tube sockets with a small amount of electrical contact cleaner. It shouldn't harm the electronics and will help clean out gunk. I think the idea is: If you were somewhere playing your amp and it sounded great, then you moved it and it sounded like crap, there's some "disconnect" in it now. Perhaps it's just one tube not making contact correctly.
    No apology needed, this place is the best! I reseated the tubes and it does sound better, I threw my JJ back in V1 and it sounds like it used to on 1/2. My parents are sleeping so I can't really turn it up. I will do that tomarrow.

    Thanks again!

  6. #6
    Forum Frontman
    Join Date
    09.15.06
    Age
    42
    Location
    Minneapolis
    Posts
    6,568
    Last Online

    07.04.16 @ 08:03 PM
    Likes
    3
    Liked 6 Times in 5 Posts

    Default

    Quote Originally Posted by iplayguitaralot View Post
    No apology needed, this place is the best! I reseated the tubes and it does sound better, I threw my JJ back in V1 and it sounds like it used to on 1/2. My parents are sleeping so I can't really turn it up. I will do that tomarrow.

    Thanks again!
    Good deal. So hopefully it wasn't anything major.

  7. #7
    Forum Frontman fudd's Avatar
    Join Date
    02.22.08
    Age
    38
    Location
    Earth
    Posts
    14,260
    Favorite VH Album

    Fair warning, 5150
    Favorite VH Song

    HAIL, love walks in, 5150
    Last Online

    @
    Likes
    1,316
    Liked 6,303 Times in 3,170 Posts


    Premium Member

    Donor

    Default

    hes right about groove tubes. i have a 5150 1 and a II and the one has grooves in it and I replaced them after a week. i would minimize the tone and gain but it would still feedback.

 

 

Similar Threads

  1. 5150 Effects Loop Problem.
    By bangerang5150 in forum Guitar Room
    Replies: 2
    Last Post: 11.13.07, 08:16 PM
  2. 5150 combo problem.
    By bcgvh in forum Guitar Room
    Replies: 5
    Last Post: 02.22.07, 12:52 PM
  3. 5150 combo problem
    By Dave King in forum Guitar Room
    Replies: 2
    Last Post: 02.23.05, 04:15 PM
  4. 5150 Head Tube problem
    By tribb in forum Guitar Room
    Replies: 3
    Last Post: 02.02.03, 10:27 PM
  5. 5150 combo hiss problem
    By rolsguitars in forum Guitar Room
    Replies: 1
    Last Post: 10.15.02, 09:30 AM

Tags for this Thread

Posting Permissions

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