Hello! New user, so can't post pix of my st-70 for another week, but I do have a question about these amps and applying a two-channel bridged matrix for center channel. Is it worth playing around with? The method I'm looking at is from a Dope From Hope article by Paul Klipsch where the L and R speakers are wired normal at 4 ohm terminals, and the 8 ohm taps are combined with 8 ohm 10W resistors, with a common ground. My ST-70 currently drives a set of '65 Klipschorns and I had a Cornwall as a center from my previous setup, but it's too big for the current space; now employing an Acoustic Research AR1 for experimentation.
I've seen other more complex matrices applied with some really oddball wiring (other than Klipsch) but has anyone here played around with pulling a center channel (technically three-channel stereo) with this amp?
Also: I will need help identifying my driver board. It's been upgraded but it seems to be a very early version of something that resembles nothing else currently available. Tube complements are 2-Mullard EF86 and 1 JAN 6189W (12AU7). No trim pads, and the board traces are really fragile and looks home-etched, no mfg markings. I upgraded the caps and tube sockets when I first got the amp some 10 years ago. I'll post pix in a week.
Thanks!
Edit: pretty sure it's an early Ned Carlson/Triode board.
I've seen other more complex matrices applied with some really oddball wiring (other than Klipsch) but has anyone here played around with pulling a center channel (technically three-channel stereo) with this amp?
Also: I will need help identifying my driver board. It's been upgraded but it seems to be a very early version of something that resembles nothing else currently available. Tube complements are 2-Mullard EF86 and 1 JAN 6189W (12AU7). No trim pads, and the board traces are really fragile and looks home-etched, no mfg markings. I upgraded the caps and tube sockets when I first got the amp some 10 years ago. I'll post pix in a week.
Thanks!
Edit: pretty sure it's an early Ned Carlson/Triode board.
Last edited by jehovaswettness on Mon Mar 05, 2018 12:06 am; edited 1 time in total (Reason for editing : further research provided more information)