X202-B Hum in Phono Section

[MacWorks]

I've got a recently acquired X202-B and never thought I would hook a turntable to it. Never say never. I am getting hum in both phono 1 and 2. Not the least bit electronically inclined, so is there...

- anything I can check by swapping tubes? if so, where

- or connect a solid state pre-amp to the X202-B for playing records? If so, how?

Thanks in advance for any feedback!

 

[fred soop]

Try connecting a ground wire from the turntable chassis to a chassis ground point on the amplifier.

 

[MacWorks]

Thanks. Ground connected on both sides.

 

[MacWorks]

Is it possible to hook up a pre-amp to the X202-B or is there no accommodation to do that?

 

[larryderouin]

Plug in an external phono preamp to AUX on the "B". check continuity between the outer shell of the RCA jacks, and chassis. The phenolic board can allow them to get loose and lose ground. Also tighten up the outer leaf's on the interconnects. If the phono jacks are in the right corner (looking from the back) and next to the output's, it may be interference from the output tubes. Had to build a shielded box (soldered to chassis) around that corner. I'll see if I can find the link.

 

[larryderouin]

https://audiokarma.org/forums/index...q-10khz-phono-squeal-volume-dependent.732992/

Test it with shorting plugs installed in the RCA Jacks. (RCA Plugs with the center and outer leads shorted together) See post #3

Good possibility the problem is in the turntable. Check all connections in the turntable (RCA Jacks, Terminal strips, muting reed switch (if it has one) and tonearm wiring to cartridge, make sure cartridge connections are absolutely clean and tight. Ohm out your turntable cables. < or = 1ohm per foot I've found for old stuff is average. Any more than that change them out.

 

[MacWorks]

Thank you, @larryderouin . Always helpful. Looks like I’ve got issues with the used turntable I purchased.

 

[Tim D]

Glad you figured it out. More often than not the hum on phono input is the fault of the turntable. I chase that a lot because I have about 15 turntables.