Bybee Quantum Purifier Review




Bybee Quantum Purifiers

Several week after I settled on the coupling capacitors to Duelund’s CAST-PIO Cu, I got a tweaking bug and I decided to try the Bybee Quantum Purifiers. I was always curious about them but never took the steps to try. To me, they were bit too pricey for something that seems controversial for their effectiveness as far as various discussion forums on the internet are concerned. But I finally decided to try as they were on 30% off sale at the Part Connexion.



After reading the company’s DIY installation guide (, I decided that I only needed to purchased one small purifier and installed them between the Power transformer and the IEC socket. This was the recommended installation for power supply circuits with tube rectification. I decided to start with the power supply tweak as this was that seemed as general agreement amongst those who like Bybee as the most effective. With Bybees installed, the sound changed dramatically much more than I had ever imagined. Quite amazing and unbelievable but it really did, however not to my liking. The sound became more refined but there were plastic like artificial texture to it. Worst is that the tonal balance completely tilted to the high frequency to the point that bass sounded anemic and overall sound was very thin, zippy and bright. I thought it may need a break-in so kept the power continuously turned on for several days. After breaking in, the sound texture improved but the tonal balance was still skewed. As I was about to write it off and de-install, I found a following posting on the Audio Asylum by uncle stu:


“As a corollary to the ground control tweaks, although Jack (Bybee) first recommended the purifiers be placed only the positive leads, I find that it is imperative to place the purifiers on the negative leads also. The placement on the positive tends to skew the tonal balance upwards, placing a purifier on the negative restores the balance in the lower region. Jack now recommends that a purifier be placed on two legs.” (

Hmmm, sounds bit like taoism’s ying and yang. The post describes exactly what I experienced. However, I had no way of judging if the proposed solution should work. I did a bit more research but I could not find anything on the internet that collaborate this. However, uncle stu seem to be running a respectable audio business and have been posting many relevant, useful and sensible comments to a number of audio forums. So on that basis, I decided to try his suggestion. I suppose, then it comes to audio/hifi, there’s only one way to find out, try and listen. It took about 10 days for my order to arrive and I installed it immediately. OMG! It really worked. Bass has returned. Now the overall sound is well balance just very slightly titled towards the high frequency, more open, refined with added details. I have encountered many strange things in this hobby over 25+ years but this is by far the most bizarre and unexplainable experience I ever had.


It’s been close to two months since I installed the second Bybee purifier and I am quite happy with the improvements they made. I do think they work and the sound do change quite a bit. The changes are in the same direction as one would get from upgrading a fuse but far greater and clearly audible. If one likes how the sound changes by installing one of the so called audiophile fuses, then I can reasonably be sure that he/she be happy with the Bybees. However, since the effect is likely to be very prominent, I would suggest that one would use them carefully in terms of where and how many as less can very well be for the better. I would also suggest anyone considering use of Bybees for the first time to read the aforementioned post in the Audioasylum.


(June 7th 2013)