The Topaz is probably my least favorite board in the Soundtracs range due to its reliability and ruggedness, but provided you treat them with care they will last you a lifetime. At least they sound good, close to the larger PC Midi and Megas desks.
Tim, from Studio Systems in the UK is probably the last major Soundtracs repairman in the world...
His Topaz page is
here in case you need more info.
I've just got a Soundtracs MRX modular split/in-line desk after three years of being mixerless (in the analog way
) since my Tascam M3700 bit the dust, and I chose it over a couple of Solo Logics (Which are good, but not modular) and a Quartz (Which was unfortunately in VERY bad shape and would've cost me a fortune to bring back to spec). What you'll find with these desks is lots of headroom and solid EQ, they are quiet, maybe not as quiet as current desks, but quiet enough for studio work... the pres and the EQ are indeed the highlights of the desk and worth the money.
Make sure you get spares for buttons, faders and knobs... they are getting hard to come by.