QQ: what level Furmann conditioner do you consider good? I find their product literature nearly useless; seems to me nearly the same marketing speak is applied to their $200 units up to their $3600 units—I can barely discern a functional difference.
-- nickgreenberg
Until you get into the EXTREMELY high end of Furman's power conditioner line, most everything gets handled by MOVs, which are there to filter voltage spikes...which are the REAL problem here. One good high voltage transient can do loads of damage, but lots of not-so-high voltage spikes will have the same cumulative effect as a rule. In here, I use a bunch of PL-8 and PL-8plus Furmans, in addition to some recently-added M-8Lx units.
And they can even protect against Stupid User Tricks...f'rinstance, I once had to plug in my Korg MS-20 (which normally has a 2-conductor power cord) "blind", as seeing the connector in that case would've required some physically-impossible contortions. Sure enough, one prong went into the "hot" leg, but the other was against the grounded Furman case. Switch on the Furman...and POP!!!
Did that fry the MS-20 (it should've)? Nope. Instead, one of the Furman's MOV's had popped and the MS-20 blew its P/S fuse due to the improper connection. That's what you WANT to happen! One annoying fuse change (which turned into a mod of putting the fuse receptacle on the back, next to the power cord) and replaced MOV later, and all was well once more. I should also note that the mods also included changing the power cord to a more sensible 3-prong, with the cord ground going to the chassis. This not only made the unit QUIETER (definitely a big deal in original AC-powered MS-20s) but it prevented the same cord insertion problem from happening again.