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Peavey Bandit Transtube 112 80w with issues

Discussion in 'Amp Central Station' started by Brendo, Nov 5, 2020.

  1. Brendo

    Brendo Tele-Holic

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    Hi everyone.

    I've managed to become the owner of a Bandit Transtube 80w amp with some issues. It's the one with the Vintage / Classic / Warm toggle on the clean channel, and the Classic / Modern / Hi Gain toggle on the lead channel. Master section has Reverb and Boost pots only. On the back is a Simulated Direct Output with a level pot, the 25% / 50% / 100% toggle, Loose / Medium / Tight damping toggle etc. (I can't find a model number, so hopefully this info dials in the actual Bandit series clearly)

    The amp powers up fine, and when placed near an electrical circuit there is a hum from the speaker. That leads me to believe that both power and speaker work.

    When a lead is plugged into either of the hi / lo gain inputs, touching the lead tips makes no sound. When a cable is plugged into the return socket in the effects loop, touching the lead tips makes a noticeable increase in the buzz.

    So...

    1 - Is this a common fault, something simple to fix?
    2 - Is it worthwhile on a $300 second hand amp (market price)?
    3 - Should I cut my losses (which were minimal), convert it to a 112 open back cabinet with the original Blue Marvel?
    4 - Any other worthwhile outcome to be suggested by you good folk?
     
  2. Pasta Player

    Pasta Player Tele-Meister

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    Jumper in and out on the effects loop then try front inputs. If it's anything like the earlier Peaveys, sometime this works. Has happened here on a couple of the earlier Peaveys... which ultimately lead to cleaning all of the input jacks - which solved the problem.
     
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  3. Timmay

    Timmay Tele-Meister

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    Cleaning the jacks with electronics cleaner/deoxidizer might well fix the issue.
     
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  4. MrCairo46

    MrCairo46 Friend of Leo's Gold Supporter

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    Common issues
    Check the input jacks where they are soldered to the board inside the amp. These joints develop micro cracks. jumper the effects loops works too
     
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  5. Peegoo

    Peegoo Poster Extraordinaire

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    This.

    Look very closely (use magnification and a bright light) at the solder pads on the back of the board where the jack connections poke through. Sometimes fractured solder joints are really hard to detect. Apply a little dab of flux and reflow each joint if any of them look suspect.

    The reason it can be one of the effects loop jacks is because each is a switching jack. With no cable plugged in, the switch in each jack is closed, allowing signal through the amp. If the switch contacts are dirty, it can cut off the signal. Jumpering the jacks with a short instrument cable opens the switches and the cable carries the signal.
     
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  6. Brendo

    Brendo Tele-Holic

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    Jumpered the effects loop, and there's still nothing from the hi / lo gain inputs.

    I'll pull the chassis and have a look when I've got more time on my hands.
     
  7. Pasta Player

    Pasta Player Tele-Meister

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    Transtube models may have different jacks - but these are the input jacks out of an early Bandit 75.

    Bandit75.png

    Likely that someone stepped on a cord and damaged the High input jack here, as it was pulled “up” from the board. Also, compare the blue-arrowed contact of the Low, to that (red arrow) of the High input. Bottom leg had also been damaged. Replaced both jacks.
     
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  8. MrCairo46

    MrCairo46 Friend of Leo's Gold Supporter

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    Those are the ones in later models too. Both my Silver Stripe and Teal had these issues. I LOVED the OD on the Silver stripe. But even after soldering, it would sometimes lose sound. Not good on a gig. Sold both and got a brand new Bandit. It should last 25 years.
     
  9. codamedia

    codamedia Poster Extraordinaire

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    Make sure you jump the "pre amp out/power amp in" on the back as well. Just to be sure.
     
  10. Brendo

    Brendo Tele-Holic

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    So, I pulled the chassis today and I can't find any solder cracks, or anything obvious that would give a reason for this preamp to not be working.

    Plugged an instrument onto the effects return, and the Poweramp worked fine.

    So query 2. I've got a cheap 5w tube head coming. Could I simply plug the speaker out on the head to the effects return on the bandit? Or should I just scrap the amp in the chassis and wire up the speaker with a jack and go direct from the head to the speaker.
     
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