Home Audioquest PowerQuest 707 – 505 and 303

Audioquest PowerQuest 707 – 505 and 303



  • Clear impact on sound
  • Nice form factor
  • Plenty of outputs


  • Low Current outputs could be better
  • PowerQuest 303 somewhat up-front
Build quality
PowerQuest by Audioquest


At the iEAR show in late 2023, we saw three new, affordable filters from Audioquest. Christened PowerQuest, this series is for people who can’t or don’t want to spend thousands of Euros on filters. The form-factor is that of the Niagara, but the prices are below that of the Niagara 1200. Interesting! We test the PowerQuest 303, 505 and 707. And we are going to torture the PowerQuest 707 on the test-bench as well. 

Regular readers of Alpha Audio know that we preach clean energy. Energy is the basis of a hi-fi system. So the key is to keep this energy clean and stable. And with the advent of switching power supplies, solar panels, charging stations on the drive way and in the street, things are not getting any better. That’s not an opinion: that’s just a fact.


Now skeptics will insist that any power supply in a device already cleans energy. A transformer already filters and otherwise there is a filter in the device itself. That’s right: a decenlty audio device also has a filter. And it will make sure that basically it’s all right. But a manufacturer in many cases will not build in a top notch filter. That’s just too expensive. In short: there is always room for improvement.

And that’s where the specialists come in. Manufacturers who have specialized entirely in power cleaning. Audioquest hired Garth Powell a few years back to set up the “power department”. We’ve seen since his arrival that all mains cabling has been overhauled and the Niagara line has been introduced. Now it’s the turn of more affordable models.


PowerQuest by Audioquest

The new PowerQuest lineup consists of the PowerQuest 303, PowerQuest 505 and finally the PowerQuest 707. Prices run from 599 for the 303 to 799 for the 505 and finally 1299 for the 707.

The increase from 799 to 1299 can be explained: the PowerQuest 707 has an interesting addition in the form of a kind of “battery” that can supply 45 Ampere directly when needed. Our programmable AC generator found that reservoir but troublesome we noticed. But more on that later.

Furthermore, the biggest difference is that the PowerQuest 303 filters differential mode only and the 505 and 707 also filter common mode. This is quite audible, we have noticed. Filters work from 30 KHz and up. We saw that also in the measurements. And compared to the 505, the PowerQuest 707 has another Current reservoir.

The construction

Audioquest obviously cannot provide the same enclosure as a Niagara 3000. The enclosures of the newcomers look basic, but fine. We find the form-factor a lot more convenient than the Niagara 1200. That one has always been a bit goofy. These new models wil do just fine in any hifi rack.

Type test
Production country
  • Brand and model: PowerQuest 303
  • Build quality: Basic, but fine
  • Overall impression: Bit up front
  • Price: €599
  • Brand and model: PowerQuest 505
  • Build quality: Basic, but fine
  • Overall impression: Nice balance, much better than 303
  • Price: €799
  • Brand and model: PowerQuest 707
  • Build quality: Basic, but fine
  • Overall impression: Nice balance, calmness and fluidity
  • Price: €1299
  • Winkels met Audioquest

    Sint-Antoniusstraat 15
    2300 Turnhout, BE
    Joseph Bensstraat 21
    1180 Ukkel, BE
    Pleinweg 136
    3083 EP Rotterdam, Zuid-Holland, NL
    Hooikade 13
    2627 Delft, Zuid Holland, NL
    Bredabaan 1031
    B-2930 Brasschaat, BE
    Pelikaanstraat 126
    2018 Antwerpen, BE
    Schoenmakersstraat 19
    6041EX Roermond, NL
    Grotestraat 23
    5931 CS Tegelen, NL
    St. Ceciliastraat 28
    5038 HA Tilburg, NL
    Geldropseweg 105
    5611 SE Eindhoven, NL
    Breestraat 146-148
    2311CX Leiden, Zuid Holland, NL
    Korte Jansstraat 11
    3512GM Utrecht, NL
    Korevaarstraat 2 e-f
    2311 JS Leiden, NL
    Koningsstraat 35
    2011TC Haarlem, Noord Holland, NL
    Theresiastraat 151 - 157
    2593 AG Den Haag, Noord Holland, NL
    Beethovenstraat 9-b
    1077 HL Amsterdam, Noord Holland, NL


    1. Aloha Jaap, I recently purchased the 707 for protection more than filtering, but I was wondering would you recommend connecting a Grimm MU2 to the high power side with an amplifier? I’m not sure if the switching mode power supply would affect the amplifier more than it was plugged in on the far low power side? Thank you for your great work. Mahalo!

    2. I don’t know what you think Jaap , but I have to say looking at the Price :
      It seems to me that for a system up to 3000/4000€ the powerquest 2/3 (200/300€) are really really good for the price. Of course Niagara or powerquest 503 might be better but we’re talking about double the price or about 800/900€ instead of 200/300€