I am not qualified to judge but all I have read in the last 60 years or so tells me you are more in the Russ Andrew's camp than Ethan Winners.
I respectfully urge other readers to take this stuff carefully with a handful of salt and check other, reliable sources.
I'm in the camp of Rupert Neve, Ron Dolby, Jim Williams, Brian Calrstrom, and Rob Zombie.
Not only I hold a ISCET cert, I have a Bachelors in Electronics, plus other certifications along the way in the past 30 years (TV/VCR repair and various Telcom and FCC certifications)
So my electronics theory background is strong, and its not cluttered with the misconceptions that seem to get fed to the diy audio engineers.
I know who Ethan Winner is, and I rocked him before on a 40KW PA system
Ok, so I shall respect your qualifications. Maybe it is the way you put things over that causes me concern? For instance, your last sentence, were you applauding Ethan or knocking him? (there is another guy here that SEEMS ok but says weird things!)
I have to wonder what the guys at www.soundonsound forum would make of you?
I find the comment about SoS reviews insulting and if reproduced in their forum probably libellous.
i think i figured out whats broken on the 286S unit, and I've got the part on the way to fix it.
I'm pretty much done with my initial mods and repairs on the 286A unit.
Seriously someone at harman needs a good talking to. some of the implementation flaws are just horrendous.
and it isn't a cost thing.
Sadly some of those flaws carried over to the S model too.
once i get the S model fixed i'll do some initial side by side testing. hopefully mid week next week.
They are not resistors, from the schematic they are RF chokes and you remove* them at your peril.
Certainly a good mic transformer will have an inter-winding shield that will all but kill RF but I would keep the chokes then check the HF response at 20kHz. If it is within a dB or so, keep them. The transformer will likely need a 'Zobel' CR network to dampen the HF resonance so that could be tweaked to get a decently flat response.
Always be cautious throwing in traffs. HF and LF resonances can occur, hum induced and, unless driven from a very low (best zero) impedance source, distortion rises with level and inversely with frequency.
well I got it working really well with the jensen transformer, however, I still had to have one instance of a capacitor in the path to isolate the two bias paths of the differential pair.
So now I have decided to order a LL1530 because it has two separate windings on the secondary, and I should be able to get dc coupled operation with that transformer. As each secondary winding will be part of the dc bias and signal path.
really well? that is a bit ambiguous what difference did it make?
how did the LL1530 work out?
the A model does have a weird grounding scheme and both models are unbalanced stages.