The Superbe is our recreation of the 1955 5E3 Deluxe - possibly the best blues amp ever made. It has a thick, spongy tone with the more compression or "sag" than any other tube amp.
It is a cathode biased Class AB amp with a 5Y3GT rectifier, 6V6GT power tubes, 12AX7 phase splitter and a 12AY7 preamp. The crazy amount of compression is caused by the fact that the power supply is really inadequate for the task - the 5Y3GT doesn't provide enough current and the filter capacitors are too small.

This was partly a cost saving decision (larger value capacitors were very expensive and physically very large in the 1950's) but also part of Leo Fender's design philosophy - to increase sales he developed a large family of amps and to save money he would use the greatest number of parts shared between the different models - he would stretch some amps up in power and scale others down to create a range from 5 to 80 Watts.
This resulted in some underpowered and some overpowered designs - the 5E3 was one whose output power was stretched beyond the capabilities of it's power supply.
When played at low volumes this has no effect but when the amp is pushed past half volume the magic happens - when you play a loud note or chord, the current is drawn from the reserve stored in the filter capacitors. This small reserve is quickly exhausted and more current is drawn from the rectifier tube. As the chord decays, it's volume falls within the range the power supply can provide and the volume builds back up, creating a very musical sustain. It's like a studio compressor with a slow attack and a one to two second release. To an extent all vintage tube amps do this but the 5E3 does it the most!
This was certainly an accidental "feature" - the 5E3 was simply a low (third to bottom) range, affordable small amp that wasn't really meant to be turned up too loud.
Blues players however loved the price and the sustain - it gives individual notes a great authority which is well suited to blues guitar's vocal qualities.
Our reproduction is identical to the original except we've added a three pronged power cord, standby switch and center tapped heater winding for less hum. Like all our amps we use Mercury Magnetics transformers and chokes, Sprague and Mallory capacitors, Switchcraft jacks, Carling switches and your choice of Weber, Celestion or Jensen speakers.