Good small/single outlet power conditioner for preamp.

Try the Furman AC215a, it's small (2 outlets) and has the features erik squires recommends.  It's about $100.

@gramophone_canada No, there is no noise when just pre and power are connected. Noise comes as soon as a DAC (two, tube or ss here to try) is connected.
I am using RCA from pre to power (and DAC to pre).
I did use a cheater plug on the DAC and it fixed the issue BUT a cheater plug is not ideal in this system. I could hear it’s affects (maybe I just need to let it settle), it added a harsh-brightness. And a cheater plug was not necessary on the DAC before this. I don’t know if it works the same with cheater plug on the pre, though.

Id actually like to not have to buy a second small filter and would rather have one that everything works with. I’ve never had hum in this system before with anything until now.

Today I am going to try the whole system on a Furutech tp609 passive power strip to see if it’s hum free. If so, I’ll dismantle the HT/TV power setup and try the Equi=Core 1800 balanced power conditioner with everything.

@psf4972 thanks for the suggestion. I looked at it but it appears to be UK based only…

wish I could edit thread title to reflect my change of heart on having two conditioners. One for all OR better yet, fixing this issue with no other purchase needed. 
 

Find a couple of PS Audio, Ultimate Outlets... make sure they are the high current model. One of the few power conditioner/tweaks I have a purchase that truly worked. Will never sell mine.

Our power spikes alot sometimes 5x a wk.i have good luck with furman although I've tried many and have many even the old monster 2000 plus 7000 huge transformers. I need it for my expensive amps I don't like loosing sound quality but if it saves me big $$$ on audio equipment it's a compromise I'll live with.have not found one to get rid of small ground loop but they all advertise they do.

It's the preamp. you changed 1 thing, problem started.

Preamp straight into the wall, no problem, thus the preamp is good, EXCEPT it is making .....?

I would get a length of wire for a new ground somewhere: start touching contacts, this one, that one: searching for some combo that ends the hum.

I did that on my new equalizer which hummed even in bypass mode, found connecting the left and right channel's grounds to each other solved the problem. Just hit or miss.