One of my KIVed project would be the Mighty Midget. I only got it working on one channel. The B+ was not enough when using the 6X5 rectifiers. Just a tad short for regulation. It was at around 290vdc. I need 300vdc for the Mighty Midget, and more if I want to use the Janus Shunt regulator. Out went the tube rectifier and in came some CREE CSD10120 babies. I'm using these  1200v 5A Schottky diodes from my parts bin.

I've also redid the Shunt Regulator onto a board and these are tested working.

The 6T10 really need a muting circuit, otherwise the amp will make some very nasty squealing noises upon power off. Tony recommended Rod Elliot's Soft-start circuit. Will have to order parts for this.

The time consuming portion is the need for a new chassis since the previous one had a hole cut for the tube rectifier already... Shucks... wonder if I should make this an all aluminium chassis... or stick with MDF and aluminium for quicker chassis construction.

Some pics here.

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.

The moskido schematics have changed since the last time I looked at it. Now they are Direct Coupled, using a DC servo to get rid of the large output capacitor. Apparently this new version is much better than the original version.

But this requires another pair of mosfet per channel and the heatsinks that I got are not enough to dissipate the additional heat... Guess I'll have to KIV this project.

In the meantime, I am going to convert the chassis that I did previously for the 6D10 Mighty Midget. Gonna go grab some parts later.

There are not enough audio DIY related posts... hopefully I'll update with some progress tomorrow. I need to work out the tube rectifier and also Janus Shunt regulator stages for my Mighty Midget.

Progress is rather slow on the UcD. Took some time to put in the shield as it will not fit. The aluminum piece is a little too large. Had to round the corners off. Then, with the screw below, it is a little too high. Had to file off the top portion where the wiring is supposed to connect to the UcD modules. Then, one of the psu harness is too short. Had to route by the side... so much for consistency.

I hope to be able to start on the signal wiring when I have time. Now currently finding out more of Steve Millett's 6T10 Mighty Midget. Heard Tony's version of this 3 watter at NoiSing08 and was very impressed by it.

Just over the weekend, I heard it at William's place with the actual 300v PSU on his 9" field coil Feastrex. First up was the driver-tormenting Sheffield Lab Drum and Track Disc.

Silence(from me)... Wow(from me)... it was just incredible...

Field coil drivers aside, I've already ordered the Takman resistors for the 6T10. The GE tube and sockets for this baby will be arriving soon as well. Will be mono blocks and using 6X4 rectifier tubes and probably my stock of Mundorf M-lytic HV cap or a combination of a GE oil cap plus the Nippon Chemi-con cap that I got from HK.

Hmm... question is, with my backlog of projects, should I start on this first? Perhaps so... it satisfies my requirements of low wattage, and esoteric (I did consider building something like the Fi 421A).