Dave:

We have thought about repairing the Seiko and that's our fallback plan if nothing else works. It is a standard 1/4" jack which has a switch built into it which disables the internal microphone when something's plugged in to it. The reason it's the fallback plan is that we're pretty clumsy at soldering and could destroy the tuner in the process!

PP:

Stroboscopic tuners have been on the market and may still be. Our favorite was one we saw which slid under the strings. You set it to E for example and tune the E string until it appears to stand still. Works in noisy environments and even in the dark.

Bev and Jerry