I just assembled my K4001. When it’s turned on I have a clean amplified signal. When it’s turned off, it makes a buzzing hum through my speaker (a mono 8 ohm horn). If I disconnect the power supply (2x 9v), the buzzing stops. If I turn the device on, the buzzing stops. This only happens when it’s off and connected to the batteries.
I’m worried about draining my batteries when not in use, and if I’m damaging anything.
I suspect a grounding issue, but I’m not sure where to start or even what to ground to. This will be a portable project in an plastic ABS case. Any suggestion would be appreciated. Thanks!
You got us confused here. How can it be ‘off’ and still be connected to the batteries?
Maybe you could draw a diagram that shows how you have connected things.
Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to a drawing,
then we can take a look and provide some feedback.
I’m using a function generator as a sound source. http://www.nuxie1.com/guides/fungen-v2-kit.html, with its own 2x 9v power supply.
WAVE_OUT is connected to the K4001 input. When I say “off” I mean the function generator power switch is turned off. Maybe I need a seperate power switch for the K4001? I want to use only one switch for the whole unit, a master switch, and not use multiple on/off switches if I can help it. Would a DPST switch do this for me?
I’m also trying to find a clever way of powering the K4001 and the FG with same two batteries, instead of using two batteries for each board. It seems wasteful and it’s inconvenient.
Thanks, I’m waiting on the new switches to arrive. On a separate note, what is the best way to use two instead of four batteries? I found an illustration here: how-to-build-hotrods.com/turn-signals.html ,under the “hey, what about hazard lights?” section. Is that depiction accurate?
