5am, can't sleep... let's draw up the concept of the Usagi-Yojimbo.

Yojimbo turned out to be a no-R no-C amp in the concept (in the signal part at least). Initially I wanted a 2:1 stepdown, if any, in the 26 preamp as it seemed like such a waste. I remember I had a set of Tribute amorphous 1:4 step-up transformers, so I could actually get back the gain of the 26 preamp which now sports a 4:1 stepdown in the output. Best of both worlds?

The supply PCBs arrived yesterday and I started soldering the parts on. Two of these will go towards the Prologue 2.0 build for the 12V and 6V heaters, the other two are for future use. I have some toroid transformers laying around that will be used for these supplies. The PCBs are $3.50 each on ebay, better than any breadboard I would cook up.

A nice package arrived today with the eTracer kit. Unpacked and started assembling.

Found a bunch of µA meters where I had rescaled a few to a more useful range and added my logo for the Assault & Battery preamp. Gotta try that again for my upcoming amps; I'll make a brief project page on rescaling them.

When you start sorting the next box and after the first 20 tubes notice that the entire box is filled with variants of the type 10. Guess what the output tube of my DHT amp will be...

So the excuse I used to convince myself to pull the trigger on this is that it is a birthday present to myself. Can't wait to try this thing out; it would eleviate the testing of all the  tubes I have here with no info for the used (or are they new) ones.

NB: This will allow me to publish accurate measurements on the different VT52 types as well.

Ordered a some bias regulator kits and DHT filament regulators from Rod Coleman. The bias regulators will go into the Prologue 2.0 output stage as well as the planned DHT amps at a later date. The filament regulators will be for those same DHT amps, giving me a total of six Coleman Regulators now, a set for each stage.

Sort all my tubes I said. It'll be fun I said.

Looking for that one tube I swear I had somewhere :)

On the bright side: I found out I have about 20 different type 26 tubes which might make for a nice photo gallery.

Dang... Just checked the registration for the vt52.com domain an noticed it was registered back in 1998, making this site just over 20 years old. Good timing for a revival :)

Ordered some of Pete Millett's high voltage regulator boards for the same amp so I can get everything quiet; a no hassle amp and I haven't really played with regulated B+ supplies all that much. This will also allow me to get away with using a single choke in the B+ and then branching off to the L/R channels. I don't feel like making complete mono supplies for this little amp, so I'm not going all-out and only using parts that I have on hand (which is a lot, so don't feel sorry for me).