Quantum Symphony Pro-Line Conditioner
Mar 14, 2008 at 12:08 AM Thread Starter Post #1 of 3

Dan Millheim

100+ Head-Fier
Sep 7, 2006
Not sure if this product has ever been discussed at length here but I would love to know if anyone else has had success with this amazing product?

I have owned various "tweak" related black boxes and this one by far is my favorite of all (see my sig. below for more). The Quantum Symphony Pro. has been discontinued but their QRT technology has been rumored to have been recently bought by Nordst to be incorporated into various new products of theirs later this year. The fact that several very high end line conditioners already license this technology first got my attention and I can now clearly see why.

The best way to translate into words what this device does to my rig is create more air, edge, instrumental placement and over all "sheen" to my sound stage. "Sheen" (not overtly unnatural in sound) is the best word that comes to mind and it really is a wonderful effect on SQ when listening on headphones.

I have had the Symphony Pro in my rig for almost a year and have experimented with it in my media room with little visual impact to my picture. For this application I would be hard pressed to recommend it BUT in an audio rig it is amazing! What I mean by this is that while some tweaks are subtle at best, the Quantum Product is, for me, a huge difference maker and worth trying. From time to time they come available on Audiogon.

Here are some links to some other reviewers:
6moons audio reviews: Quantum Symphony Pro
SoundStage! Equipment Review - Quantum Products Symphony Power-Line Conditioner (1/2000)

So again, anyone that uses this product, could you please post your reviews as well. Thanks!
Mar 14, 2008 at 12:47 AM Post #2 of 3
I used to have one of these. It *does* change sound like many other power conditioning devices do, but as usual it depends on one's system and preferenes.

I found its effect to be not too different from devices that use capacitor-filtering to reject EMI/RFI, meaning smoothing out the high treble range with less grit, introducing ease to the presentation while the midrange becomes more the focal point (likely due to less noticeable treble).

Ultimately, I chose to not use it and went with another solution, but it's worth trying in your system. What I would probably try is use the smaller "quantum" devices *well away* from your audio system to reduce noise generated by your non-audio electronics. I've seen people use them in rooms away from the system, even in the bathrooms, kitchens, etc!
Mar 14, 2008 at 2:49 AM Post #3 of 3
Thanks for your comments Jon_L. I have experience with PS Audio Noise Harvesters, Blue Circle Noise Pillows and a product from Locus Design Group along the same lines as you described. With the three I mentioned, I had them placed in various locations down stream (around my house) away from my rig and, for me, the effects were not the same as the QRT Symphony Pro product plugged into the outlet my rig is on.

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