I think I spotted an error on the schematics regarding all instances of the 100uF DC feedback electrolytics. On the Elicit schematics these seem reverse polarized with respect to ground (see C61 on left image). The power amp sections are of the same topology as the second gain stage of the phono section pictured here, they have the same 100uF DC feedback electrolytics there and they are reversed too.
What makes me believe it is an error is that I also have shematics for the amplifier's smaller brother in those series the Elex, which is essentially the same design with less power and somewhat lesser quality components, but it's so close it uses the same circuit board. Its DC feedback electrolytics are in the seemingly more correct orientation (see right image).
Furthermore, the simulation shows that the node between the 820R resistor (R157) and the cap is 15mV positive, no matter in which orientation that cap is placed, but obviously one is wrong. Perhaps an electrolytic can tolerate a few millivolts reverse poalrization I don't know, but the discrepancy between schematics hints that the Elicit one in erroneous. Plus even if it's only a few mV, it will always operate in reverse polarity, which can't be good, no?
What makes me believe it is an error is that I also have shematics for the amplifier's smaller brother in those series the Elex, which is essentially the same design with less power and somewhat lesser quality components, but it's so close it uses the same circuit board. Its DC feedback electrolytics are in the seemingly more correct orientation (see right image).
Furthermore, the simulation shows that the node between the 820R resistor (R157) and the cap is 15mV positive, no matter in which orientation that cap is placed, but obviously one is wrong. Perhaps an electrolytic can tolerate a few millivolts reverse poalrization I don't know, but the discrepancy between schematics hints that the Elicit one in erroneous. Plus even if it's only a few mV, it will always operate in reverse polarity, which can't be good, no?
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Reading on the subject in one of my books, the bipolar electrolytic capacitors being basically two caps in series each has to be twice the intended final size of course, so "defects are multiplied by a factor of four over a normal bipolar capacitor, so their performance is poor". (Morgan Jones, Valve Amplifiers 3rd Ed.)
So no bipolars for me. I'll check the proper orientation on the actual board.
So no bipolars for me. I'll check the proper orientation on the actual board.