All of a sudden getting a hum in my system?

I am getting a hum that gets louder as you turn up the volume. I disconnected my VPI Classic One turntable and I am still getting the hum.I disconnected my three month old Manley Chinook and hooked up my old Belles 20A phono pre-amp and there is no hum. So the Manley Chinook seems to be the culprit. I called Manley Labs yesterday but they are closed until January 2.Any suggestions for resolving this problem would be greatly appreciated.
Make sure the VPI and the Manley are properly grounded, including the tonearm and turntable bearing hub. tubes are very sensitive to grounding issues. If everything else is grounded properly, try a cheater plug on the Chinook.
I agree with Jmcgrogan2. You probably are looking at a grounding issue (or possibly some other weird thing on the circuit).

If all was well with the Chinook for three months and you have not moved anything around in the system (because, if so, perhaps a solder joint broke loose or something like that), I'd actually look towards something that may have recently been plugged into the circuit elsewhere in the house.

Hums dont magically appear in a system that was non-humming system for 3 months. Like I said, if you moved components around, then maybe I could see it. Otherwise, you may have something else dirty on the line a few rooms over.

The hail-mary longshot is that something in the Chinook has gone bad (a tube, etc) but that is unlikely, IMO.

BTW, good luck with resolving this. My biggest pet-peeve with ANY system is noise. It drives me crazy, even if it is really slight. Sure, I may not be able to hear it with the music on, but just knowing it is there ticks me off.
Do you have cable television plugged into your system? I had some hum going on, and when I unplugged the cable, it disappeared. I then added an inline ground to the cable coax, and it made it go away.
Thanks for the responses.Everything seems to be grounded properly. I have not moved anything or plugged something into another circuit. My home theater system is in another room and I do not have cable. I am taking the Chinook to a friends today to see if it hums when connected to another system.I will talk to a Manley Labs tech before experimenting with cheater plugs or RCA shorting plugs.
Just connected the Chinook to a friends system and the hum is still there getting louder as you turn up the volume.I guess the only thing to do now is to call Manley Labs and see what they suggest.
Have you tried changing tubes?
I have not tried changing tubes.I will talk to a Manley Labs tech about changing tubes. I am new to tube equipment so I don't have any extras lying around.
Hey Montgomery - your troubleshooting steps are very sound (plugging the Chinook into your buddy's system). I hope you resolve the problem soon. Please update us when you nail down what the exact problem turns out to be.
Montgomery - any resolution to this issue? Response from Manley? Having the same problem and appears that my Chinook is the culprit.
Hi Montgomery, Have you resolved your hum issue with the Chinook? I'm having the same issue with mine.

Sorry for the late response but I have not visited Audiogon in awhile.
I sent the Chinook to Manley and they said the problem was with a capacitor.So with insurance that cost me over $90.00 which is not covered by the warranty to have a capacitor replaced.
I got the Chinook back and it was working alright for awhile.But several times recently while playing a record I am getting some loud pops followed by a loud hum from my speakers.Also several times recently I have noticed speaker oscillation as soon as the needle hits the record,this is before the music starts.
Is my Chinook a lemon?
Loud pop's and hums usually are related to tubes and/or caps. With you unit's history it is probably caps. FWIW, it is recommended for any tube component user to have a spare set of tubes on hand so he can rule out tubes issues when problems occur. BTW with most tube problems you only hear the problem in one channel unless the bad tube is shared by both channels. It's under warranty so Manley should handle for you (again).

Re speaker oscillation - I assume that what you mean is that the woofer cone is moving in and out substantially but there is no apparent increase in bass. If that is so the typical problem is a mismatch of cartridge and tone arm (mass v compliance) which would be best resolved by getting the appropriate stuff in the first place, although it is possible to get a subsonic filter that would help reduce it. It is also possible to get a device to damp tone arm movement that might help. I had this problem many years ago and I traced it to the fact that my arm had damping capacity built in, all I had to do was add some fluid to the oil well.

Hope that helps a bit.
How weird I have the same problem. I am using a ZU/DL103 with a modified RB250 and have a hum problem when arm is grounded to the chassis ground of the Manley Chinook. However when i disconnect the ground the hum goes away but have a occasional loud pop.
Manley sent me a new Chinook a year ago.After about a month I started getting an occasional pop and hum. It has occurred three times in the last three weeks so I e-mailed the Manley service department today.My first experience with tubes has been a frustrating one,but I do love the sound.My advice would be to e-mail Good Luck!