No announcement yet.

Music Man RD 112 - Sound drops out


  • Time
  • Show
Clear All
new posts

  • Music Man RD 112 - Sound drops out

    Hi Everyone,

    I am hoping someone here can help me out with this issue: I've used a Music Man RD 112, hybrid amp, for about two years now. Since the last few months, when I play it, the sound occasionally drops out completely, only to randomly come back on again a few minutes later. It seems to happen in specific places, I've played it many places without any issues, but a few times it has failed me in the middle of a gig.

    I've taken it to an amp tech, he played it for a couple of hours but it seemed to work fine and he couldn't find a problem. Has anyone else experienced this issue? Any help would be greatly appreciated.

  • #2

    Those are noted for having bad op amps. Once they get hot they fail. You can use tech freeze spray to isolate the bad one. If its distorted before going down to no sound, check the reverb circuit op amp.

    Look for bad solder too. I have seen a couple come in with bad solder on the tube sockets. These have fairly high plate voltages so be sure to discharge the caps before servicing.


    • sytar
      sytar commented
      Editing a comment

      Thanks for your input. Also good to note perhaps that at times no sound would come out when I first started playing and I had to loudly strum my guitar a couple of times and it would suddenly come on.

  • #3

    Have you tested the Tubes?  It may be one of them is going bad. Also I'm a little disappointed in your Amp Tech, if he's any good he could have checked the preamp section and checked the OP's and other circuits, even I can do that and I'm not an Amp Tech. The SS part can be fixed easy enough if you can find the problem and the parts. 


    • HKSblade2
      HKSblade2 commented
      Editing a comment

      Many Many techs who get no fault founds and return them to the customer. After a 48 hr test typical assumption is bad cable, guitar jack, external pedals, etc. Intermittent problems are not so simple to track down when you run a business.

      I partner service with another tech. He hates SS and I do those for him. SS power amps, mixers, rack fx, SS guitar amps, Modeling amps, etc. He does the easier more forgiving work.. tube amps. He had to do a 32x8 mixer board whan I was on vacation. I came back and he told me gatt damn I never knew you have to take all those knobs, nuts, and crap off just to get to the damn boards. He thought mixer pcb's had a bottom panel for easy service. LOL

      Not much anything SS is built with service in mind.

  • #4
    I have the same amp that I bought new in 1981. It suffered the exact same problem. I replaced the op amps and capacitors. No longer have the problem. I am having a new problem with the amp switching from limiter channel to clean channel when I turn the volume up. Seems to be low voltage problem going to the IC switch.


    • vanistheman
      vanistheman commented
      Editing a comment

      I had a similar problem and if I remember right I think it was the pots. A simple fix, just spray some DeOxit or whatever...