Hi all!
It's probably not the most gentle way to start in a forum with a post asking some questions in a six-month old discussion, but maybe this is stil interesting, also for other users..
First of all - I really appreciated reading this discussion and I'm very curious how the MCA will perform driving a three-way transmissionline I designed and build some month ago.
But let me start with some questions regarding the circuit.
1) In the power supply schematics of the ZCA, you start the C-part with a 'low'-capacitance low-ESR-cap, that I don't really understand at this position.
2) The supply ends with a 100nF cap, that I basically know from catching hf-spikes directly at a switching transistor. I don't know if this guy really makes sence. Somebody compared with and without this one? Partly, this discussion in the neighbour-forum (
http://www.diyaudio.com/forums/power-su ... -caps.html ) deals with this topic..
3) A general thing - is a symmetric pi-filter (CLC) usually prefered over an asymmetric one? More precise - is it preferable to set C1 = C2 or do you focus just on their separately seen low-pass-capability?
4) Next to the input-signal, there is a 100k resistor in parallel - does this guy defines the input-impedance? Should it be set relative to the used preamp-output-impedance to get best results? If I read correctly a user in this discussion left it away, so it's a non-crucial component? By leaving it away, one could design an Even-More-Minimal-Component-Amplifier (EMMCA) :-p
5) What is the idea behind the 100µF-cap attached to the 1M-resistor and the 100k-Poti?
6) As in point 4, a user in this discussion left away the 1Ohm resistor attached to the emitter. How would this influence the circuit? Would somebody recomment keeping or leaving this one away?
I'm looking forward to hear from somebody. Thank you guys!
Cheers,
Jannis