Just replaced the stock Gen 1 Sonicap 3.3 mF bypassed with Platinum Sonicap 0.01 mF coupling caps in Dodd Battery Powered preamp with V-Cap ODAM 1mF (100KOhm amp input impedance) bypassed with V-Cap CuTF 0.01mF caps. Wow! Giant killer preamp is now kill anything preamp! Also using LiFePO4 batteries and Victron 24V 5amp charger on preamp...getting 40 hour run time :)
Really think anyone contemplating new preamp purchase should consider coupling cap upgrade as well...