I wanted to share my latest project with you guys. I call it the Orpus 24. If you spell Orpus backwards you get Supro.
It is a single channel interpretation of the original Model 6424. I didn't find a need for two channels and I also omitted the tremolo from the original.
http://el34world.com/charts/Schematics/files/supro/supro_s6424.pdfThis amp uses 6973 power tubes which is new for me. I see them as a 12ax7 on steroids or a 6V6 in a small package.
The colour theme I went with is blue. I purchased some carolina blue tolex several months back and planned to use it on this project. The faceplate was laser etched by a local business to me.
I am using two lamps, one for power on (violet) and another for standby (blue). I like this feature.
It is a pretty simple design, two 12ax7's, two 6973's and a 5Y3 rectifier. The first 12ax7 is paralleled and the 6973's are also individually ran in parallel.
I added a little eye candy with a blue LED strip inside the cage and then a DC voltmeter on the front of the cage that is monitoring the bias voltage. When you play the amp, it wiggles between 25 and 30+ volts. It adds a bit of fun.
I chose a greenback as the speaker compliment on this one. I must have tried 20 speakers before I found one I really liked. At first I was planning to use a 1x15" cabinet I have loaded with a warehouse G15C speaker but I did't like the pair.
Thanks for looking!
TG
…you can see in one of the pics my other Supro amp, the Thunderbolt I built last year. It's kind of a father and son Supro family!
Topic: Orpus 24 (Supro) Project (Read 1802 times)