08-18-2017, 08:13 PM
The evolution of the Gemini series is an interesting one, however it's more linear than you might expect. its goes roughly like this.
gemini 1 -> Gemini 2 -> GV22
The Gemini 1 was the first in the series. This amp is also really unique, and It is the original Gemini in every way. The design demonstrates the tension that existed within ampeg at the time. It was still owned by Everett hull who was known to have an absolute distaste for rock and roll and wanted clean / clear sounding amplifiers for jazz musicians. At the time many of the designers were rock musicians, guys like ken Fischer, Dennis Kager, Bob Teneyck, and Gene Andre. I believe the Gemini 1 was the closest ampeg could come at the time to making a rock amplifier. It definitely rocks, but it doesn't growl like a blackface deluxe.
The Gemini 2 was basically a beefed up Gemini 1. Using a 15 inch speaker, larger cabinet, and configuring the power tubes in fixed bias rather than cathode bias. this required that the gain stage before the cathodyne phase inverter receive a cathode bypass capacitor. The Gemini 2 could put out about 35W The tremolo circuit was also swapped for the one used in the b12xt. (the vibe/trem)
the GV-22 swapped the 7591a power tubes used in the previous generations for 6L6GC, They also changed the speaker complement to 2x12. This boosted output power to 40-45W.
although not technically a gemini, and introduced the same year as the GV22 (1969) The B42x and B22x were in many ways the next logical progression of the GV-22
The B42X/B22x boosted the B+ to 500V and swapped the 6L6GC tubes used in the GV22 to 7027a tubes. (this output section was very similar to the B25, or V3. those amplifiers did not have reverb or tremolo) this amp was available as a head (B42x), or a vertical 2x12 combo (b22x) and was a solid 55W
The gv22 is a really great amplifier. I prefer the 2x12 configuration to the 1x15 gemini 2. but i honestly think the 7591 is such an amazing output tube. if I had it my way, the Gemini 1 would have the vibe/trem circuit.
one additional point of interest is the ST-42. This is a solid state amplifier that ampeg made. It is essentially the solid-state counterpart to the gv22. the vacuum tube circuits are almost tube for tube replaced by transistors. its really cool. it has a really beefy sound. I owned one for a while with the matching 4x12. really awesome amp, but way too loud.
gemini 1 -> Gemini 2 -> GV22
The Gemini 1 was the first in the series. This amp is also really unique, and It is the original Gemini in every way. The design demonstrates the tension that existed within ampeg at the time. It was still owned by Everett hull who was known to have an absolute distaste for rock and roll and wanted clean / clear sounding amplifiers for jazz musicians. At the time many of the designers were rock musicians, guys like ken Fischer, Dennis Kager, Bob Teneyck, and Gene Andre. I believe the Gemini 1 was the closest ampeg could come at the time to making a rock amplifier. It definitely rocks, but it doesn't growl like a blackface deluxe.
The Gemini 2 was basically a beefed up Gemini 1. Using a 15 inch speaker, larger cabinet, and configuring the power tubes in fixed bias rather than cathode bias. this required that the gain stage before the cathodyne phase inverter receive a cathode bypass capacitor. The Gemini 2 could put out about 35W The tremolo circuit was also swapped for the one used in the b12xt. (the vibe/trem)
the GV-22 swapped the 7591a power tubes used in the previous generations for 6L6GC, They also changed the speaker complement to 2x12. This boosted output power to 40-45W.
although not technically a gemini, and introduced the same year as the GV22 (1969) The B42x and B22x were in many ways the next logical progression of the GV-22
The B42X/B22x boosted the B+ to 500V and swapped the 6L6GC tubes used in the GV22 to 7027a tubes. (this output section was very similar to the B25, or V3. those amplifiers did not have reverb or tremolo) this amp was available as a head (B42x), or a vertical 2x12 combo (b22x) and was a solid 55W
The gv22 is a really great amplifier. I prefer the 2x12 configuration to the 1x15 gemini 2. but i honestly think the 7591 is such an amazing output tube. if I had it my way, the Gemini 1 would have the vibe/trem circuit.
one additional point of interest is the ST-42. This is a solid state amplifier that ampeg made. It is essentially the solid-state counterpart to the gv22. the vacuum tube circuits are almost tube for tube replaced by transistors. its really cool. it has a really beefy sound. I owned one for a while with the matching 4x12. really awesome amp, but way too loud.