Name: Steve Kennedy
Email: steve@pacair.com
Subject: speaker wiring question
Thread: 246
Time: Sun, 11 Nov 2001 06:40:11 UTC
Your hum is most likely due to power supply capacitors that need to be replaced or a bad AC ground or a guitar with a single coil pickup just picking it up from the amp's transformer.
It can (but not always)make a difference which jack is used for the internal speakers. The 212 and head units with the Series output jacks do not differentiate between Main and External Speaker jacks... they are both labeled "Speaker" and are interchangeable , assuming their switch closures (when disconnected) are working properly.
On all the other "parallel-jack" MM amps the Main Speaker jack has a built-in short-to-ground switch. You must use this jack FIRST, then the jack marked "Extension for extra speakers.
Steve