Any ideas on how to troubleshoot this?
OMG, did Huff just say what he wrote? The pope may excommunicate him!
Get rid of the POS sub and get a real sub. Like a JL Fathom. :laugh:...Tom's right in one respect...the Sunfires shake themselves to death. Currently have 4 and all but 1 are in need of service or will need it soon. Got a plate amp at VHF right now. The Fathom is a little pricy though. I heard the Epic subs do a great job at a reasonable price but that's just cross talk on the forums.
And a tip for slowing down walking sunfire subs: plop a stack of granite samples on top with blue tack in between layers, make him do heavy squats if he wants to walk.
...the auto on-off time is set by a single resistor-capacitor combination. R40 and C18. These are 5.2 megohms and 22uF. You will find these at the bottom-left corner of the quad jfet opamp U2 (MC34004). The 22uF cap looks to be a higher quality that all the other electrolytics.
Or, some pre-amps have switched rear panel outlets.
I am slowly removing imperfections from the Sunfire True Sub Mark IV sub. The recent output cap replacements were a huge improvement - the hum appears to be gone and it sounds cleaner and tighter. The next frontier is the auto-on circuit. It takes a while for this cube to detect there is music playing and kick in. I have to significantly pump up the volume in the pre or go fiddle with the potentiometer in the plate amp so it wakes up (the latter erases the level setpoint, so it is a bit of pain). Any ideas on how to troubleshoot this?
Thanks,
OBG