T-Rex Reborn 08/06/2018, Sold 01/23/19


The T-Rex Reborn project is complete, and it looks and sounds amazing!


The amplifier shown here was built with Iron and other misc. parts re-claimed from another project. Scroll down for info on the original T-Rex amplifier.

This is the most powerful 300B SE amplifier I have ever made. In order to take full advantage of the Plitron OPT’s, I decided to run the 300B’s at a higher current than the original amplifier.

This amp’s 300B’s run slightly on the hot side…. 350V at 80mA, the result is 9.24 Watts into 8 ohms.


Input: 2 volts for full power

Power: 9.24 Watts into 8 ohms

Frequency (Measured at 2.2 Watts):

20Hz-20Khz at -.29 dB

12Hz-77KHz at -3dB

DC Heaters for all valves

Rectifier: GZ34 (Slow warm up rectifier)

Input/Driver: 6SH7’s wired as triodes 

The Original T-Rex

The Original T-Rex Amplifier Show Here

Several years ago I found an article by Dick Olsher and John Broskie called

“The T-Rex SET Amplifier: A DIY Project”

What a name for an amplifier, T-Rex!

T-Rex was a high end 300B stereo amplifier used as a test bed to evaluate different OPT’s and to test different input/driver stages. Here’s the link to the original article:


Over the years, T-Rex had been beat up pretty badly, broken bones, missing teeth and lots of scars. When Dick Olsher contacted me to repair the beast I jumped at the opportunity! Well it turned out the repairing T-Rex was not cost effective. I kept T-Rex for parts and Dick purchased one of my 300B amps.

This page will showcase the re building, which I started on 5/25/18.

T-Rex Reborn uses the GZ34 rectifier and Plitron Iron from the original amp. That’s about all the DNA they share. The new amp will follow the “Less is more” philosophy and use the same circuit as my other 300B amps.

The size of the new amp is about 60% of the original and it will be a few pounds lighter.

T-Rex had a 2 choke power supply with a tube voltage regulator.

T-Rex Reborn will  use one choke and loose the voltage regulator.

-Stay tuned


6/11/18 Update

The New Amp


Looking better with the iron painted and 3 coats of satin varnish on the new walnut chassis! I wanted the same general look as my standard line of 300B amplifiers... This is what we came up with.

Started the wiring


I hate having to splice wires, so the layout is based on the length of wires I had to work with. At this point all that's completed is the rectifier wiring.

6/14/2018 Update, Wiring almost done.

High Voltage Power Supply


Low Voltage Power Supply


300B Cathode Resistors


Almost Done with the Wiring


300B Cathode Bypass Caps