Least expensive plug-in power conditioner that works

Hi, I went through this with my system.  Look at the specs. It's quiet right?

So, first I bought DX Engineering EMI RFI filters for the ethernet line.  One on each end $50.  I bought these as a trial to prove to myself that this conditioning stuff works.  Then I would buy something more audiophile.  About the same time, I got a new modem, still coax but a linear power supply.  The speakers sounded better.  The I bought a Furman Elite 15i.   Plugged all my equipment into it.  Around the house I plugged all the chargers, dimmers, etc into a furman ss6b.  I have 3 of those.  I have less than $500 invested.  I am a firm believer the better you keep noise out of your streaming system.  The sound is much better: Details, 3d and wide soundstage, bass i never knew could be so good, much more natural sounding.

@daledeee1 +1

This deal seems hard to beat: https://www.markertek.com/product/fur-p8proc/furman-p-8-pro-c-power-conditioner-20-amp

Cullen works for me. Think it was around $100 or so.

I've just been going through exactly this same exercise. Some comments that I posted in another forum:

 

I listened to the rest of the test scenarios that I was considering

1. Cheap Computer Surge Protector - as a control
2. Audioquest Niagara 1200
3, Furman PST-8D Power Conditioner
4. Audioquest Niagara 1200 with amplifier plugged into the wall
5. Furman PST-8D Power Conditioner with amplifier plugged into the wall

3, Furman PST-8D Power Conditioner
My initial impression was that plugging my system into the Furman made music sound calmer. After several more minutes of listening, it seemed like the Furman was taking some life out of the music in comparison to both the cheap computer surge protector and the AQ Niagara. The muted dynamics and overall flatness of the sound wasn't nearly as dramatic as with the Topaz Ultra-Isolator in place, but it was noticeable especially in comparison to when my system was plugged into both the cheap computer surge protector and the AQ Niagara. 

1. Cheap Computer Surge Protector - as a control
In terms of liveliness and tonal color, having my system plugged into the computer surge protector sounded surprisingly good.

2. Audioquest Niagara 1200
The effect of the Niagara 1200 seemed to convey the best parts of the sound from the Furman and from the cheap computer surge protector. It conveyed the calmness that I heard with the Furman in place while losing none of the liveliness with the computer surge protector was in place. With a perceived lower noise floor, the Niagara also allowed more detail resolution and tonal color. These last two factors seemed to make music easier to follow and understand with better clarity and separation between individual voices and instruments.

5. Furman PST-8D Power Conditioner with amplifier plugged into the wall
Plugging my amplifier into the wall with remaining components into the Furman MIGHT have resulted in a slight improvement in dynamics, but any difference was so slight that I don't think I could tell the difference in an A/B test.

4. Audioquest Niagara 1200 with amplifier plugged into the wall
No discernable difference at all, but I don't think my amp draws that much current.

Unfortunately what has sounded best in my system was the most expensive of my options. But it's been good to be able to at least compare the AQ Niagara 1200 to other options to at least appreciate what I'm getting in the Niagara 1200. I'm listening to Allan Toussaint's The Bright Mississippi album right now via digital and it's unmistakable that I'm hearing more in this album than previously without the Niagara 1200. The AQ Niagara 1200 is definitely a keeper for me.

Next steps is to try out some different power cables on the Niagara 1200 in place of the Audioquest NRG-Z3 that I've been using. Trying out power cables on the Niagara 1200 will be the easiest equipment swap of any equipment that I've tested. The Niagara 1200 is two feet from the nearest power outlet so trying out different power cables will just be a matter of unplugging one power cable and plugging in another. First step is to try out two cheaper power cables that I have on hand to see if different power cables even have any affect on sound quality.
1. Tripp-Lite Heavy Duty power cable: See how a "normal", $15 non-audiophile power cable sounds. 
2. Shunyata Venom V14