I had a QX4 for a while, but I don't have it any longer. Did it do something good? Yes. Do I think that's it's worth $2,500.00? No. If you go that route and do as Nordost suggest, you'll keep adding QX4s at $2,500.00 a pop.
Did you see this post: http://forum.audiogon.com/cgi-bin/fr.pl?htech&1264477351&openusid&zzLiguy&4&5#Liguy
Liguy is an electrical engineer, notice what he says about the QV2. If he is indeed correct, then there's a cheaper alternative.
Right before David Magnan's website went down, he recommended using three Enacom AC filters on the AC line with your system: http://store.acousticsounds.com/d/55403/Enacom-Enacom_AC_Line_Noise_Eliminator-Line_Conditioners
That's $225.00 for all three. I bought them and they work really well. I would like to suggest that you try the Enacom AC filters and see what you think. It's a small investment compared to the QV2, and miniscule investment compared to a QX4.
Thats helpful Chuck. In as far as I understand what Quantum is about, I thought it was'nt to do with cleaning the mains. If it is I have a good power regenerator the Pure Power APS 1050 to do that and I would'nt need a QX4. Therefore I am not sure that the Enacom AC filters would be a help. I hope the QV2 does something of what the QX4 does. I see the thread you referred to, someone is about to add a QV2 to a QX4, I hope he will report back.
I was under the impression that the QX4 did clean the mains, but I may well be wrong about that.
I had a really good conditioner and the QX4, and bought an isolation transformer that did more for my system than those two pieces. I sold the conditioner and the QX4 and went happily about my business.
Since you have a Pure Power APS 1050, I'd try to borrow a QX4 and a QV2 and try them one at a time to see if they do help and are worth the price. You hate spending $2,500.00 and finding out that it doesn't do what you thought or that your Pure Power is taking care of everything.
The Pure Power pieces are supposed to be really good!
I have the PurePower APS 2000. Plugging in the PP2000 into the QX4 lowered the noise floor significantly in my system. Cleanliness, clarity, and most sonic characteristics improved at a level of a component upgrade. To get the most out of the QX4, you will need to upgrade its power chord (I use the Elrod Statement.) and optimize its placement within your system set-up; I have mine sitting on top of the CD player.
That's good to know John. I rate Pure Power very highly, so it's nice to know you found a clear improvement with the QX4.
Do you pass the mains through the QX4 to the APS 2000. I know that is the way you are supposed to do it, but I spoke to a Nordost rep at the UK national show last year. He suggested passing a cord from your conditioner to the QX4, then into a low draw piece of electronics, such as a pre amp or CD player. This avoids any risk of exceeding the current available through the QX4. If you place that unit in the middle of the rack, it will still boost the other components of your system. It might be worth trying.
If I read their web site correctly it seems that they are simply filtering or "Cleaning the mains".
From their website:
"QRTs proprietary circuitry acts at the source of the problem, reducing EMF noise and RFI interference effects on the mains waveform, audio and video signals and it does it without limiting the voltage swing or altering the impedance of the AC supply. Which makes the job of your hi-fis power supplies and active components much, much easier and thats what you hear from your system or see on your screen. Use a QRT purifier and youll experience a lower noise floor, greater clarity and separation and increased dynamic range, qualities that are just as apparent (and measurable) when it comes to the color, definition and detail on your AV display as they are in the context of a really great stereo set up. The result? Greater overall musical and visual coherence, more stable perspectives, greater realism."
If someone knows how to do this without using classical EMI and RFI filters they sure have stumped me.
The differences between Quantum devices are too small to be detected. ;)
David12, My QX4 is plugged into the wall and the PurePower 2000 is plugged into the QX4. The CD player and amplifier are fed by the PurePower (no pre-amp). When needed, the PP has reserve in its battery; so, I have not had current problems with my 600 watt per channel RMS amplifier. In fact, the amplifier sounds better going through the PurePower than directly to the wall.
Slightly off thread...but what's the deal with PurePower.
I have not heard of them before and was just about to buy a Shunyata Hydra V-Ray 2.
I see it is a power regenerator rather than a powerline conditioner.
So what is better?
Mauidj, PurePower 2000 is superb; it added clarity, cleanliness and dynamics to my system and provides constant 120V/60Hz power. I bought it from Brent Rainwater at rainwateraudio.com. Brent can answer your question better than I can. Also purepoweraps.com website is very informative.
I second that, it isolates you from the mains via a battery, creating a clean mains source. I have'nt tried many power conditioners, only the Kemp power source before. I am really impressed at what the 1050 has done for my system, I've been using it for 3 years now.
The company will advise on the capacity you need from their regenerator. I have the 1050, John the 2000. I have seen it said that whatever power you may need the 2000 is a better unit, with better results, but I can't confirm that. For the price, I think it is a very good deal.
Getting back to the differences between devices, Doug reported differences are minimal, that is helpful, but has anyone done an A/B comparison between them. The answer is probably not, but I'd like to hear if anyone has.
Well I found a QX4 second hand. They don't appear too often, which says something about whether they work. Well it certainly seems to, with greater clarity and a bigger soundstage.
I still don't think they are worth the full retail cost.
I was being facetious, but I'm not surprised at your conclusion.