Tools, Tones and Toys for Guitarists
GIBSON GA-30 GUITAR AMPLIFIER SCHEMATICS This is one of the GA-30 amps – there were a few by the sounds of it. While they share a similar topology, there are clearly some differences from the one above. Apart from changing the circuit, their appearance also varies over time – I’m not going to try and … Read more
6SJ7 preamp, 6SN7 paraphase inverter, 2 x 6V6 with local negative feedback. GIBSON BR6-F GUITAR AMPLIFIER SCHEMATIC Clearly a bit of work has been done on this one – just using the pic as an example of circuit construction. Low impedance input 6SJ7 PRE Ra 220k Rk 2k2 20u bypass Screen 2m2, 50n bypass 10n … Read more
5879 pentode premap, which is an improved version of the E8F6 – uses a Vox style cut control across the plates of the phase inverter. Paraphase inverter, driving 2 x cathode biased 6V6. GIBSON GA-40 GUITAR AMPLIFIER SCHEMATIC