12-10-2014, 03:40 PM
Yes, the GV-22 and the GV-15 both have a 30uF first node reservoir cap, which I think it would be better if it were a bit larger.
As far as using the amp for bass (with speakers that can handle the low end), the power amp and power supply design have many similarities to the fixed bias B-15 which works pretty well for bass. Ampeg bounced around on the size of the power supply caps in the B-15 with the different revisions. A lot of the early revisions had 40uF. That they went down to 30uF and they increased the voltage rating of the cap to 600V. When they introduced the Heritage B-15 a few years ago, they stiffened up the power supply. The first node had a 47uF cap followed by a choke and then another 47uF cap. Jess Oliver has said that he felt that the amp sounds better with a stiffer power supply and held out for it in the Heritage design.
As you know, in a bass amp, a larger first node capacitance will provide more headroom and the amp can better cope with the lower notes which draw more from the power supply. With a guitar amp, if you are looking for an early onset of distortion, having less capacitance helps. Designing an amp for both bass and guitar often involves some compromises.
As far as using the amp for bass (with speakers that can handle the low end), the power amp and power supply design have many similarities to the fixed bias B-15 which works pretty well for bass. Ampeg bounced around on the size of the power supply caps in the B-15 with the different revisions. A lot of the early revisions had 40uF. That they went down to 30uF and they increased the voltage rating of the cap to 600V. When they introduced the Heritage B-15 a few years ago, they stiffened up the power supply. The first node had a 47uF cap followed by a choke and then another 47uF cap. Jess Oliver has said that he felt that the amp sounds better with a stiffer power supply and held out for it in the Heritage design.
As you know, in a bass amp, a larger first node capacitance will provide more headroom and the amp can better cope with the lower notes which draw more from the power supply. With a guitar amp, if you are looking for an early onset of distortion, having less capacitance helps. Designing an amp for both bass and guitar often involves some compromises.