If to look at the Melquiades schematic in the channel “A” you will see 78H first order low pass filter.
The low-pass filter in Milq and the low-pass filters generally is great subject of interest for me as I do not have final judgment about them. Let me to explain. I did not use e coil – based filter in LF chain of Milq because it would be a very large coil with relatively large DCR. The RC filter is small, the quality of the little cap is very high and the filtration is made by shunting the signal, so the signal does not flow via the cap. Everything is fine, right?
Well, yes and no. I learned long time ago that shunted caps are OK with DC but they are dangers in AC. If you have a more or less LF capable playbacks then make an experiment: run your playback from dedicated, bare and non-adulterated mains and then shunt the mains with an appropriate capacitor of 2-3uF. It will act as a low pass filter but also, no matter how good the cap would be then sound will be changing it the LF characteristic in band pass. In other words the bass will be getting screwed. So, we the Cats fight with any capacitors in primary…even if it is the capacitors in my neighbor house.
OK, but how about the .068uF cap in the Melquiades channel “A” – it is the same shunted cap in AC line? What I was building the Milq I was planning to experiment with it but I never did. Now to do it would be to r-arrange the Milq biasing and frankly I do not want to make any experiment any more. Still, I have some purely extrapolative proposal that the line filtration by RC method for the channels that handle the lower frequency might be not the most advanced way to go. If someone would make some experiment with it and come to some observation regarding the L vs. RC and their relation to lower bass then please let me know and I will put that 15-20H coke in play as a low-pass filter if I need to.
Rgs, Romy the Cat
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche