Ok, not the movie, but rather the r-core power transformer that I got from Chung at vt4c. I wanted to try a r-core power transformer as I have not tried them in a tube amplifier before. Kinda regretting the decision though...

Chung said that the primary windings are not marked correctly, thus I have wired them out of phase, causing the hum. He suggested that I try to wire the black wires as 0 and 230v and connect the red and orange together to get 230vac on the primary winding.

I tried this out and the hum is lesser, however, the transformer heats up after 10 seconds or so.

I decided to wait for him to measure the transformer when he gets to his warehouse. I've stopped work on the amps for now. In the meantime, I'm expecting to pick up my Nixie Tube clock kit from the post office tomorrow. Yeah... Always wanted to build one of these.

Gonna look around for a nice enclosure to house this baby. ;)

now i'll have the opportunity to try the hybrid power supply. the good thing about a blog is the "diary"-like effect. I use it to write notes to myself... and in this case, is to remind myself that I need to use this topology for the Mighty Midget since my r-core power transformer (R0080-043) does not have a center tap.

according to the original author, there was no difference in measurements between a pure tube based power supply and this hybrid power supply. so, what then, is the advantage of implementing this? purely to cater for power transformers without a center tap... notably the Lundahls in this case. ;)

horror of horrors... the 6D10 compactron socket that I got are not the correct ones! I got the 9 pins instead of the 12 pins... argh...

guess i have to wire up the rest of the connections and the power supply sections first...

above is the work in progress janus shunt regulator, with 12w ohmite rheostats and kiwames in key locations. the power supply will be rectified by rca 6ax5gt, then 22.5uF GE oil capacitors, then the janus shunt regulator with mundorf m-lytics.

i reused the moskido chassis for the 6t10 mighty midget. had to drill new holes for mounting of the r-core power transformer (R0080-043) from vt4c.com and also additional holes for mounting of the james output transformer. the moskido chassis had 2 octal tube holes already drilled. i will have to use the front one for the rca 6ax5gt and the rear one for the ge 6t10 compactron. the janus regulator will be on a separate copper plate. i sawed it from my m10 preamp chassis (an early project that was decommissioned).

no matter how i planned, i will miss some parts... this time round, i missed the 200R cathode resistors for the mighty midget. all of the resistors to be used there are takman rex carbon film resistors. got to replace with kiwame...

some pics here.