Reverb Not Working On Only One Channel Of My Mesa?

Discussion in 'Gear & Equipment' started by ragnorok, Feb 14, 2017.

  1. ragnorok

    ragnorok SS.org Regular

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    Hey guys i wasn't sure where to post this at so i threw it in here and in the tech forum. I bought a second hand Road King 2 the other day, love the amp but it does need a couple new pre amp tubes (i hope) as my channel 4 suddenly starting running at very low volume. Around the same time this happened my reverb stopped working on my 1st channel. It works fine on all my other channels though :scratch:.


    Now this is my first serious all tube amplifier so I'm still a bit of a noob. i have some new mesa pre amp and power tubes coming in the mail today that I'm gonna swap out but i feel like that issue will probably not be fixed (maybe not even my channel 4 volume issue for that matter). There's pretty much zero shops around me that do amp tech, so if anything major is going on with it I'll have to drive pretty far out of town. But in the mean time, does any one have any suggestions on possible causes? I could really use all the help I can get guys
     
  2. tedtan

    tedtan SS.org Regular

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    If the channel is cutting out, the reverb issue could be associated with that. Change the tubes and see how it goes.

    If its still not working after you change the tubes, take it to a tech as it won't be an easy fix if its working on three channels but not the fourth.
     
  3. cGoEcYk

    cGoEcYk SS.org Regular

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    Sometimes the preamp tubes have multiple purposes. You'd need to look at a diagram but it's possible that the bad chan 4 tube also has chan 1 reverb running through it. Swapping the preamp tubes should help rule out a few issues either way.
     
  4. vick1000

    vick1000 SS.org Regular

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    Swap the tubes around, start with swaping V1 with each other spot in turn, you'll find the culprit.
     
  5. macgruber

    macgruber cat enthusiast

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    v4 in the preamp (4th closest to the input socket) is the reverb driver send/return tube. if i recall correctly it's the same one used for all channels. it seems odd that it would work on one channel and not the other. i reckon it might possibly be a switching issue with the relays. if swapping tubes doesn't work for you, send it to a good tech :)
     

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