Been running the KX-100 a couple of times per week for about a year and was trying out a Miracord 46 TT with an R700e cart that I was refurbing and it just didn't sound right. It was a bit dull and lacking in dimensionality. I rotated in my Dual 1019 with M91ED and that didn't really sound much better. Well, I figured I'd been running it too long without checking the bias and guess what? Yep, it was a little off. Re-did the bias (its got an IBAM) and put it back in rotation and sounds better. It's amazing what a little bias adjustment will do for the SQ! The brightness is better and back to where I remembered it should be.
It was running about 39V across the small signal tube heater string. I thought I remember that I should be shooting for maybe 42V or a bit more. The output tubes were drawing about 41ma each. I bumped them up to about 42.5ma and the heater string ended up at 41V.
Question for the group. Is 42.5ma a lot for this bias/heater arrangement or is this expected? Should I be bumping up the voltage on the heater string to 42V or a bit more? (That would be more cathode current, but if it's necessary, I will do it.) I just hate straining the old stock output tubes in it.
Eventually, I'll circle back on it and do an EFB and separate the heater string with its' own PS. I've got the Radio Shack filament transformer that Dave uses in his threads to do that separation. Just so many units in the queue right now and not enough time. Gosh this is fun. I love this hobby.
