AtomikPi
500+ Head-Fier
You really can't go wrong with the B22, assuming you want a wire with gain.
I've heard the ZD; nice, clean, non-tubey amp but I don't love tubes regardless.
I've heard the Phoenix - comes close to or maybe equals the B22.
I haven't heard the GSX - it's a bit overpriced compared to the B22 (betas go between $1,XXX and $3000) but it's supported by a manufacturer and is a nice wire with gain design if you don't want to deal with DIY.
I would stay away from the Apache and Rudistor - not great designs and overpriced in my opinion. Apache is class B. The Rudistors have a history of poor wiring and inflated specs.
I've heard the ZD; nice, clean, non-tubey amp but I don't love tubes regardless.
I've heard the Phoenix - comes close to or maybe equals the B22.
I haven't heard the GSX - it's a bit overpriced compared to the B22 (betas go between $1,XXX and $3000) but it's supported by a manufacturer and is a nice wire with gain design if you don't want to deal with DIY.
I would stay away from the Apache and Rudistor - not great designs and overpriced in my opinion. Apache is class B. The Rudistors have a history of poor wiring and inflated specs.