Bassman(my wild guess is audio, not fishing), welcome. If you don't want to have the 43 repaired or put up with the inconveniences you now have, a replacement is certainly justifiable. No, the 771 or any other similar amplifier won't be sonically superior, since if your 43 is otherwise still in good condition it amplifies transparently. The advantage would be in features, not basic amplification.

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Enjoy the music, not the equipment.