You can hear my MSA Legend Pedal Steel guitar and a Fender Classic Vibe telecaster played through a Gibson
BR-9 all tube amp. This amp was originally packaged as a set with a companion Gibson BR-9 lap steel guitar
and was sold around the year 1949..
There's no tone control and only a volume control. It's a bit more powerful sounding than a fender Vibro-Champ.
The tone is a bit weaker in the midrange but still pleasing enough to sit and play for hours at home with a straight tele
plugged into it.
For the steel parts I used a Boss RV-5 reverb set on hall and a Guyatone MD-3 delay unit in line with my Goodrich model 120 pot pedal. The guitar parts used only the Boss RV-5.
Looking at the schematic you can see that this is a real minimal parts amp. It uses an interstage transformer instead of a phase inverter triode to feed the push pull 6V6's. I've noted the actual plate and power supply voltages on the schematic which is the final wiring and is a bit different from the original. Some changes were necessary because the original field coil speaker's field coil was open as was the output transformer. I used a Deluxe Reverb output transformer and added a choke to compensate for the missing speaker field coil and a series power dropping resistor to keep the plate voltages within spec. To add to my woes the interstage transformer had an open secondary winding and I used a Mercury Magnetics interstage transformer in its place. The Mercury unit seems to match the AC gain and DC bias characteristics of the original as the amp sounds just great and has tons of gain at high volume without overloading at low vulume settings. I used an 8 ohm speaker (the original was 4 ohms) to match the output of the Deluxe Reverb output transformer. I've got $170.58 in final parts cost.
Parts List /Changes
The recording below was recorded and mastered in 16 bits and then converted to an mp3 file at 320kbps. See my other web pages in this series of tube amp recordings that feature a few other Fender amps including the blackface Vibro Champ, Super Champ XD, Deluxe Reverb, Princeton Reverb and the Blues Junior Tweed. To my ears, the Deluxe Reverb is the tone winner for both guitar and pedal steel.