Unfortunately, you can't call Sonic Frontiers since they're out of business. The Parts Connection is apparently starting up again, though. Try www.partsconnexion.com, and note the spelling. They listed a phone number that's no good--yet? They said something about early April. Anyway, those guys would be able to advise you, so I'd advise you to persist in trying to contact them. Good luck!
Malfunctioning Anthem Pre 1
I've been offered an used Sonic Frontiers Anthem Pre 1 Preamp at a bargain price ( US$ 495.00). However, this unit has problems: when connected to the AC outlet, the 5AR4 rectifier tube in the power source and the 6922 tubes in the line section, as well as the LED of the preamp, are not on as they should. Needless to say the preamp remains silent. Is it worthwhile? Or do you think that there is a major damage in the unit? Thanks for your kind attention!