I installed the shunt regulator board a couple days ago, and the DC filament board today. The shunt regulator impacted high frequency performance the most obviously, introduced a touch of sparkle and high end clarity. To me, sonically similar to adding a Speedball to a Crack. Sounds even more awesome!
The DC board completely silenced a pretty loud heater hum, which prior to, could be heard from 10 feet away, so very nice!
Like a dunce, I was bending the lead of the very last 0.13 ohm 3W resistor needed to complete the DC filament install, and suddenly the lead snapped off, WTF ?!?! Because, as I discovered, I was "bending" it with my side cutters, doh. F it! Decided to voltage test the amp anyway even though it was missing that one resistor. After staring at the circuit for a couple minutes I realized the added resistors increase the voltage feeding the heater, being paralleled with the existing 0.15 ohm resistors, dropping the resistance to about 0.07 ohms. So, testing without one should be safe.
Turns out in my case my heater voltages are already running a bit hot, the socket with both of the new 0.13's installed was running too high (2.71 VDC), vs almost too high on the socket where I'd only installed one of them (2.62 VDC). I ended up removing all of the new 0.13 ohm resistors to get the correct target 2.5 VDC on both sockets. So accidentally cutting off that lead was the accidentally right thing to do. Hah.
And with that, my stripped-down pimped-out Stereomour II is officially finished. The Stereomour/Moreplay is an absolutely delicious sonic combination, thanks to the awesome crew at Bottlehead for creating them! And thanks to all who have offered encouragement and advice. Much appreciated!
