Extension cord advice

It all depends on if you can hear it or not. Try plugging the turntable & phono preamp into an extension cord only and see if you can detect additional noise. Depending on the design & quality of your preamp, it might be dead quiet with either. If you don't hear a difference, you have your answer.

I am not super concerned about surge protection -- is there much benefit to noise attenuation given that I'm not using a true conditioner?

DeKay

Here are the only advantages over an extension cord.

6 outlets that are circuit breaker protected and EMI/RFI noise attenuation.

 polanskyd OP: No surge suppressor in an extension cord!

Thanks for all the responses. I'm using a Furman SS-6. Is there any real benefit to this over an extension cord?

Are you using a Furman extension cord or a Furman conditioner? If just a cord, since it is just for your turntable & phono preamp, you don't need a heavy gauge cord. Just get a lighter gauge cord (maybe shielded) that will please your wife.

There are two major features of a Furman I recommend:  LiFT and SMP.  This unit has both in the smallest possible form factor.

Signal Cable…excellent product at a ridiculously inexpensive price!

These are a great option and a great value.  They come in different configurations, and they are built like a tank! I have several and will vouch for them.  They also come with a generously long cord.  If the cord is too long for your needs, you can disassemble the unit, cut the cord and resolder it.  Did that to a couple of them.

Amazon.com: Tripp Lite ISOBAR8ULTRA Isobar 8 Outlet Surge Protector Power Strip, 12ft Cord, Right-Angle Plug, Metal Lifetime Limited Warranty & Dollar 50,000 Insurance White : Electronics