Sub woofer output port does not seem to work on my kenwood VR 407, checked sub woofer on another system - works fine, any easy solutions?

It sounds like the problem is not with your VR-606. If you hear a hum from the sub, the problem is more likely to be in the sub's built-in power amplifier. However, it is worth resetting the amplifier to factory presets. To do this, unplug the power cable from the mains supply and reconnect whilst holding down the power on/standby key. If the hum persists, connect any powered speaker to the sub-out socket, power on and listen for the hum. If no hum then suspect the powered sub amp. Turn the sub on with no connection to the Kenwood VR-606. If hum persists, the sub has a problem and will need to be replaced or repaired. By the way, you said there is a low frequency hum through the 'speakers' for about 30 mins. Is that all speakers or just the sub? Hope this helps.
Cheers, Don.

yes it very much has everything to with it. your sub out is at a pre-amp lvl, so you can route that signal to another amp, then to your passive sub, or get a powered sub

I inherited a Kenwood SW 505 Sub woofer. I don't know if it works I plug it in but no lights.

Grab the free manual and start at the beginning. This IS a new install since the memories are probably back to defaults if it was unplugged for awhile.

http://www.retrevo.com/support/Kenwood-VR-407-Receivers-manual/id/480ag200/t/2/

this like your amplify was damaged change amplify circuit, it will work

Connect the amplifier input to the VR-407 using the receiver's REC OUT jacks for the MD/TAPE input on the back panel. This is a fixed line-level output for recording, and will work fine for driving the additional amp.

The manual will show you how to enable, test and adjust the Subwoofer Output.

http://www.retrevo.com/support/Kenwood-VR-8060-Receivers-manual/id/480ci254/t/2/

Any powered sub-woofer will work with it. Check the back of the Technics, make sure there is an RCA output labeled "Sub-woofer" or "Woofer" or "Sub". If so, you can get any brand of powered sub woofer and it will work. A powered sub-woofer is one with an amplifier for the sub built into the box and you will need to plug it into an A/C outlet as well. The only exceptions to what will work with this unit is to make sure you are not buying a sub-woofer that is made to only work with the companion unit it is originally sold with. Many Panasonic and JVC sub woofers are like this. Just look for a sub-woofer that is not part of any system. Velodyne makes some really great sub-woofers that would work nice with yours, but they can be a little expensive, but they are very good.

If your Technics has no RCA output for the sub-woofer, you will need to make sure that whatever powered sub-woofer you buy has a speaker level input for it. Most powered sub-woofers have this feature, so that you may just run the front speaker outputs of the receiver into the subwoofer and then the sub-woofer will have a set of speaker outputs right below the speaker inputs so you can still have your front speakers connected to that and not loose anything from your system.

I hope I have explained this in a manner you will understand easy, if not just post whatever questions you may have right on this thread and I will get back to you as soon as possible.

It would also be appreciated if you could rate this solution if you no longer need any help from me. If you do require more help, please wait to rate this until we are finished. That way I do not get an undeserved bad rating when we have not even finished our communications.
By the way, A "Thanks for trying" and "Helpful" rating are really not good, they always end up lowering my overall score.

Dave

download the manual from this link. It will show you how

http://www.retrevo.com/support/Kenwood-VR-407-Receivers-manual/id/480ag200/t/2/

"Sub-woofer output not working" problem, and notify you when a new solution is offered.
Press the setup key on the front of the receiver
Select the subw setting
Move the multicontrol knob until the sub woofer is on
Turn off the receiver and turn back on- the subwoofer should be on

The operator manual can be downloaded on the web site--- free

http://www.retrevo.com/support/Kenwood-VR-507-Receivers-manual/id/480ag219/t/2/