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Gibson Falcon GA19RVT
Repair

Picture
Here is a super-cool Gibson Falcon GA19RVT in need of attention.  It has an unusual complement of valves, i, 3 x 6EU7, 1 x 7199, 2z 6V6GT in fixed bias and a 5Y3GT rectifier.

The amp was working but the owner thought it had become too hummy.  It needed a good fettling.  One of the valve bases was very loose, a couple of electrolytics needed changing (big cigar!) and it needed the reverb hum sorting out. It was also quite dirty and needed the usual service stuff doing.

The reverb in this model uses a 7199 valve, which is quite known to be quite hummy anyway.  I changed it for another but it was just the same.

After trying all sorts of tricks and inspecting the grounding system thoroughly I was stumped.  The amp sounded great with the reverb tube pulled and  was absolutely hum free.  It was noted thet the reverb effect was very strong and only needed to be set at around 1 or 2.  I had checked every component and replaced a couple of resitors and caps but nothing reduced the hum.  In the end, I removed one end of a cathode bipass cap to significantly reduce the gain of the offending reverb recovery valve.  It worked quite well and got rid of most of the background hum.  You could still get plenty of good "surf splash" and more subtle ambience at around 3.

The owner was chuffed to bits with his fresh sounding vintage Gibson. He decided in the end to just pull the valve and use his reverb pedal instead. These amps have a great tone and a lovely tremolo. But I hear that many suffer with the noisy reverb issue.
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  • Repairs & Servicing
    • Guitar Amp Service & Repair
    • Business Card
  • Filmosound
    • Filmosound Guitar Amps
    • Filmo New Style
    • Filmonator Prototype
    • Testimonials
  • Contact
  • Amps & Stuff
    • WEM / WATKINS >
      • Watkins Clubman
      • Watkins Westminster
      • Watkins Westminster Mk 9
      • WEM Control ER15 No. 1
      • WEM Control HR 30
      • WEM Dominator Mk3
      • Watkins Copicat Mark 2
      • Wem Watkins Copicat Mk 3
      • Wem ER100
      • Wem PA100
    • Baldwin Burns Amplifier
    • Carlsbro CS 60 PA
    • Elpico AC52
    • Leo Fender >
      • Fender Concert Repair
      • Fender Twin Reverb 1977 Silverface
      • Fender Twin Reverb 1972 Silverface
      • Fender Blues Deluxe
      • Fender Musicmaster Bass Amp
      • Musicman RP 112 Sixty-five
    • Gibson >
      • Gibson Mercury
      • Gibson Falcon GA19RVT
      • Lab Series >
        • Lab Series L2 Service and Repair
        • Lab Series L5 100W Combo (Gibson/Norlin)
    • Hiwatt Lead 50R Combo
    • Marshall >
      • Marshall Artiste
      • Marshall Superbass Mk2 100W Head and Cab Service Repair
    • Miscellaneous Amps >
      • Harmony H307x
      • Hotpup 5F1 Champ
      • Impact 60
      • Mystery Amp
      • RSC Bass Major
    • Orange >
      • Orange OR120 1970s Service and Repair
      • Orange TH 30 repair
    • Schaller KV 40
    • Selmer >
      • Selmer Constellation 20
      • Selmer Treble & Bass Mk 2
      • Selmer T&B 50R SV
    • Traynor YGL 3 Mark 3
    • Tripletone Amp Conversion
    • VOX >
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      • Vox AC 50 Repair and Overhaul
  • Blog
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  • Other
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