Description
Classy. great sounding piece of Australian music history, The Moody GA-35 Vibralux.
Just back from a full going over by Tim Occleshaw at the Tone Lab.
Here is what he had to say about it:
"The Moody Vibralux is a vintage Australian guitar amp, made in Sydney in the early 1960’s. the GA-35 is a twin channel combo with reverb and tremolo.
This example has been recapped (date unknown) and has had modifications to the reverb circuit so that the reverb driver is now a current production valve (I have further modified and simplified it to use a 12AU7, in a configuration much like that used by Ampeg). The reverb tank is a Gibbs model dated 1964 and likely to be original. The tremolo is a so-called ‘bias wiggle’, very much like that used by Supro and Gretsch in their early amps, as well as the Fender Vibro Champ and Marshall 18 Watt.
The speakers are also likely original – 2 x Rola 12PEG. The power transformer and choke are original. The output transformer is a replacement; a Classictone 40-18006. These are a good quality vintage-styled transformer, made in Chicago, Illinois.
The circuit design of the GA-35 is unusual in that it not only blends the two channels (which can also be ‘jumpered’, if desired), it also blends the reverb signal so that it is possible to have ONLY the reverb’s output for a highly saturated extreme surf-like reverb tone.
The amp’s uncommon design also includes two separate chassis – a preamp chassis with the inputs and controls at the top of the cabinet, and a power amp chassis with transformers, output valves and speaker output at the bottom of the cabinet. The two are connected by several cables inside the amp. This can make the Moody susceptible to some RFI noise, however it is a low gain amp and this was not a major problem in my testing.
The amp has a new set of valves consisting of 2 x EL34 output valves and 3 x 12AX7 preamp valves, plus a 12AU7 reverb driver. The only original valve is a 6BL8 in the phase inverter position on the power chassis. Should it ever be necessary, a NOS 6BL8 can be found at vintage valve stores in Australia for around $15-25, or it can be replaced with a current production 6BM8 though this requires some rewiring of the valve socket as the pins are different."
Made in Sin City, NSW...in the 1960s.