[cheap-Jack]

Hi.

And if I were to contact Morrow, he would simply say  "buy my shielded phono cable"." My standard unshielded cables will be far more prone to hum in a phono application". This is just a guess of course, but I think I'm close.

Well, what else you can do if you really like Morrow's sound. Either replace it with Morrrow shielded ICs or return it for good & hunt for some other brandnames to trial & error.

That's the dilamma of audio consumers at large.
Thanks goodness, I know how to build pure silver ICs & power cords right so I don't need to go hunting around & spending big.

c-J

[threadkiller]

Now it's getting deep...

[SteveFord]

I built some unshielded twisted silver interconnects and they don't hum with my old square motor WT unless I put in this one RCA tube in the preamp and then there is a slight hum.
Change the tube to another one and no hum.
Who knows.

[threadkiller]

Hi Steve,
Sounds like that one tube is microphonic... It happens.
Often when the tube is long in the tooth.