I have both an SA 20 and an NP 220 gold version - sort of. The SA 20 is nice sounding but not exactly reference yet I doubt I'll ever sell it. I really like it.
The NP220 (hi-output)has all the works except the wiring & the Vishays found in the Platinum version now offered. It also has 120,000 uF Black Gate main supply and V-Caps for coupling and uses Jan 6188 6SL7s. It sounded very nice even before the BGs were added so I definately think the upgrade is worth it. I'd get a new tranny if I were upgrading as these have been known to die (mine did)and I'd do the premium at least.
Rolling tubes in this or changing the coupling caps significantly changes the sound so if you're not quite getting what you want you mat try experimenting.
Since Michael's selling new Aria amps I don't think he's doing many upgrades. For the cost of the Platinum upgrade you can buy an Aria which I'm sure is a similar circuit design.
The NP220 (hi-output)has all the works except the wiring & the Vishays found in the Platinum version now offered. It also has 120,000 uF Black Gate main supply and V-Caps for coupling and uses Jan 6188 6SL7s. It sounded very nice even before the BGs were added so I definately think the upgrade is worth it. I'd get a new tranny if I were upgrading as these have been known to die (mine did)and I'd do the premium at least.
Rolling tubes in this or changing the coupling caps significantly changes the sound so if you're not quite getting what you want you mat try experimenting.
Since Michael's selling new Aria amps I don't think he's doing many upgrades. For the cost of the Platinum upgrade you can buy an Aria which I'm sure is a similar circuit design.