Phono stage hum

My amp (parasound a21) has a ground lift option and the hum is still there when enabled.  Would testing a cheater plug do anything different?

I will confirm the TT rca solder joint to make sure it is ok - but if there was an issue wouldn’t it be present on the other phono stage (sim audio lp5.3)?

I would think you are right @otherones.
I guess chinook had some issues before according to google search. Might have to give them a call. I would try a cheater plug first tho.

Did you buy it new from a dealer?

Does the Chinook run a  lot higher gain than the simaudio?
Is the gain adjustable on it?
Could account for some of the excess hum
Could be your expensive tt and wires are more sensitive to the gain difference than the cheaper tt ?

My older Teac tn300 never gave me any hum no matter what was in front or behind of it, My Nottingham on the other hand is a LOT more sensitive to things like cables, ac power lines, phono stage gain etc.

Call Manley tech support.  I had a SE version that developed a hum.  After various steps of troubleshooting they had me send it back.  They rotated one board 90 deg and solved the problem.

As noted above, the hum is isolated to the Manley, not the other units. Both channels. The most likely common point between the two channels is the power supply in the Manley. It could be a cap in the power supply or a different defective component in the ps. But just as a test, try reversing the power input to the unit, if that is possible in the Chinook. Might also try plugging all the electronics into the same wall outlet.  Maybe relocate the Chinook farther away from the cartridge to see if the cart is picking up hum from the phono stage.