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BSG qøl Signal Completion Stage


Of all the exciting new products, innovations, and breakthroughs in audio science that are claimed for 2012, I suspect that the BSG Technologies qøl™ Signal Completion Stage will be the most talked-about by year end. Already the subject of numerous reviews, mostly positive, skeptics are having a field day with this unique component whose designer reports that it does what no other component can do: restore phase relationships in recorded sound to create a more natural acoustic presentation. Clearly, any designer that talks in terms of “phase layering”, “signal recovery” and other attributes unique to his or her product will face a battle finding an open-minded audience, but when the product in question is a standalone enhancement stage (though BSG prefer the term “completion” stage) that requires insertion into your critical signal path, then purists who espouse simplicity will also line up in the doubters column. Welcome to the world of BSG Technologies.

When I learned of the qøl™ I was intrigued but doubtful. After all, surely this was just another (albeit pricier) type of buffer or processor working on some opaque principle that could hardly be “natural” for an audio system? But then, what is natural about anything in the audio reproduction chain? If people are reporting jaw-dropping experiences when the qøl is inserted into their rigs, maybe this was worthy of audition. I’d been down this road before with less than happy results (tube buffers and ground enhancers failed to float my boat) but perhaps this was different. Naturally, review samples are in hot demand but I was more than pleasantly surprised by the positive response from BSG who told me they would provide HiFi’Zine with a sample as soon as one was available. True to their word, a month later I receive notice that one is on the way. Since late April, I’ve had the qøl installed in my reference rig undergoing a thorough examination.

BSG Qol signal completion stage, front

Installation and set-up is as straightforward as it gets. Though it comes with four inputs and selector buttons to allow switching between sources, meaning you can run it before the preamplification stage, on the recommendation of BSG’s Larry Kay I placed the qøl between preamp and power amps, running a pair of balanced Huffman interconnects from my VRE-1 preamp to the qøl and a pair of PS Audio Reference balanced interconnects from qøl to my Spectron Monos. I later switched in High Fidelity Cables between preamp, qol and power amps to have a consistent wiring loom (see review in the June 2012 issue). Power everything up and the qøl is ready to go, with preamp operations used to control source and volume as usual.

With its standard component size, silver faceplate and blue indicator lights, the qøl draws little attention to itself. It does come with a small plastic remote control (guaranteed to slip into any gap in your sofa or otherwise lose itself about your room) which serves the basic purposes of source selection (if needed), mono operation, display dimming, and bypassing the stage if you want to remove it from the signal path – though of course, you still have those cables in the way.

Over the last couple of months I’ve had it in and out of my system, played with power cords, and even tried it in a cheaper second system of modest old components to get a handle on just how this new device worked in typical rigs. I make no attempt here to understand or examine the claims of the manufacturer, what follows is my experience listening closely to the qøl on music and equipment I know well in my own home.

What does it sound like?

My first reactions to the qøl were somewhat mixed. As soon as I turned it on and played music I tried to avoid critical listening as I was sure everything needed some time to settle; but the temptation to hear the effects as I switched the qøl in and out of the system proved too great. Well, with due respect to Oscar Wilde, temptation is sometimes best avoided. I started out with a reaction that might have been best surmised as “is that it’? Yes, I could hear a difference, and yes, the qøl seemed to add more life and presence to the music but the difference was relatively subtle. Some report a gain difference between the settings although BSG claim there is no measurable gain added by qøl, only “more information,” but it is obvious to me that with the qøl engaged, everything seems louder. I frankly find the “more information” idea hard to get my head around since measurement of information (as opposed to data) is difficult to quantify, and further, if you add another instrument to a musical piece you are also, in some sense, adding “more information” but that has little impact on reproduced volume.

This, perhaps, is to quibble over the way qøl works (or is described as working in the product literature), which is not my goal here. I want to report what I heard and what I believe an open-minded listener might hear in a properly set-up audio system. That said, we would be having no arguments about gain levels if BSG had not put a bypass button on the remote. It’s hard to imagine they are trying to trick you with a simple gain boost if they also make that shift so easy to catch with a remote button – so recognize this effect and do your comparisons the old-fashioned way, with the qøl truly in or out of the system, if you want to get the full measure of its impact in your rig.

Over the last three months my initial reaction has changed with experience and I am now firmly in the camp of those who think the qøl adds something beneficial to the sound reproduction of my rig (though I suspect the word “add” here only serves to fuel the fires for some). Take that for what it is, but let me try to explain what I hear as clearly as language will allow.

First, the most noticeable sonic attribute is the increased separation of instruments. This manifests itself in several ways, depending on the music, but most obvious to my ears was the effect on bass in rock music. On music I’ve listened to for years, I was made aware of a layer of bass guitar reproduction that simply was not discernible without the qøl. When you try to follow a bass guitar line in loud rock, it invariably blends in places with the kick drum or is obscured by the power chords from guitars or keyboards. In a sense, the bass is always there but in most rock recordings, the distinction between instruments that you can find at a live performance blurs at some points within a track as layers are added to the recording. On the remastered CD of Ritchie Blackmore’s Rainbow self-titled debut album from 1975 I noticed how the bass line seemed to bubble along in the distinctive manner of a musician playing independently of the drummer and other instruments, which caused me to listen closely to this aspect on other recordings. Sure enough, the ability to hear the bass played note for note as a separate instrument was as noticeable on jazz recordings as it was on rock. Take for example the Tord Gustavsen Trio’s “The Ground” (ECM, 2003). Track seven, “Kneeling Down”, a moody, slow moving instrumental that I’ve heard over 100 times, took on a new form for me with the qøl engaged. The bass now outlined a steady, almost independent 4-beat rhythm that gave the tune a slightly slow swing feel, with the other instruments laid out around this structure, completely altering my appreciation of the track as I was used to hearing it. I can tell you, this can be slightly disconcerting when you hear it.

Second, and not independent from the first point about instrumental separation, is the within-instrument articulation that qøl seems to enhance. Sticking with Tord, you can hear in places where his fingering on chords is precisely timed to strike the notes together and where he does so with the smallest gap between notes, giving the chord the slightest arpeggio feel. One can listen for this without qøl engaged and find it, but it’s more apparently part of the musical picture presented to you with qøl in the chain. And therein lies much of what this intriguing component does for you, it seems to make obvious to the listener some key parts of the musical picture that create a fuller, richer, experience of the music. Rapidly picked guitar lines or quick-bowed strings are somehow brought more clearly into focus, be it Pat Metheny or Jascha Heifetz. Transient attack and decay is just that much cleaner, particularly so on percussion where I heard old jazz recordings come to life with renewed energy. The qøl seems to deliver a sonic paradox, it provides more of everything, especially silence, allowing the music to breath.

Third, and perhaps most importantly, the qøl manages to provide these qualities without sacrificing timbre. In fact, in many cases the accurate portrayal of the instrument is genuinely improved by the Signal Completion Stage. Guitar strings, both acoustic and electric seem to ring more true, the acoustic bass has more wooden body and string rattle, particularly heard on older jazz recordings such as Ellis in Wonderland (Verve, 1955), a great set from a group led by Herb Ellis with Ray Brown on bass (which on the Verve CD re-release sounds otherwise a little lost, especially on the first session cuts of this twin sessions recording). Piano recordings seem to come to life with qøl. Fred Hersch’s Live at Maybach is a wonderful concert performance that is well-recorded and proven just about excellent sounding on every system I’ve played it. In my reference rig with the qøl engaged it sounded better than ever.

Over the last few months I’ve rediscovered some parts of my collection again and the qøl just kept me examining instrumental pieces in order to pin down just what it seemed to be doing. Janos Starker’s recordings of Kodaly’s solo works for cello are rightly celebrated and I’ve lately been enjoying the Period Classics CD release of the “Legendary Period LPs Vol 1,” which contains Starker in remarkable form on Kodaly’s Sonata for Unaccompanied Cello, Op8., the Duo for Violin and Cello, Op. 7, and the Sonata for Cello and Piano, Op 4. The quality of the sound here is remarkable – all the more so given the revelations in the sleeve notes that they recorded these without any real clue as to what they were doing technologically: Starker would edit the recordings by cutting and splicing the tape by hand himself. The music is powerful, and the beauty of Starker’s playing, particularly on the Unaccompanied sonata, is striking. The qøl took my experience of this recording a notch higher and caused me to go on a binge of single-instrument recordings, including three versions of the Bach Suites for Unaccompanied Cello, to help me get my ears around how qøl affected instrumental timbre. While the music is wonderful with or without the qøl, in each case I felt the qøl in the circuit seemed to reveal a little more texture to the meeting of bow and strings, and perhaps a little more air around the music. Having sat literally feet away from some great players, including recently a chance to hear Anne Akiko Meyers play an unamplified Stradivarius, it’s difficult to describe just how a live instrument differs from a recording but it’s something in the lightness yet richness of reality which makes a mockery of many audiophile attributes. The qøl, with the Starker recordings, takes me a step more toward the ultimate goal of transporting me to the space where that instrument was originally recorded. I cannot really articulate it better than this.

BSG Qol signal completion stage, rear

My exploration of single instrument recordings took me to the one I know best, guitar. A reminder of Eliot Fisk’s brilliance on Paganini is always welcome if exhausting, and I started there before pulling out various single or dual guitar recordings, both acoustic and amplified, including Jim Hall and Pat Metheny’s duets collection, solo Lenny Breau, Joe Pass session recordings, and – because I could not resist – various selections of my old Howard Roberts LPs (a guilty indulgence in 60s lounge jazz with some amazing playing from Mr. Roberts backed up by top session players) and of course, my ever faithful reference of Ronnie Earl’s Grateful Heart. It was with guitar recordings that I really noticed how the qøl tended to reveal more of the dynamics in the music, the places where, for example, Fisk picked harder with a finger during a run to give rhythmic drive or syncopation to the music. Subtle details, for sure, but once heard, like all the subtle details of audio reproduction, it’s hard not to want them permanently.

A reaction some listeners to the qøl have reported is a “pushing” of the soundstage forward at the listener, which some find enhancing and others distorting the musical reproduction. I cannot report experiencing this in a consistent manner in my setup. Instead, in soundstage terms I felt the qøl gave the music more freedom, creating a more tangible space in which instruments could be placed outside of the boxes of the speakers. Unlike others I did not experience this singularly in terms of front-back soundstage shift but more in the clearer placement of instruments across the stage. This came with an added benefit, these placements remained relatively fixed even when I changed position, meaning the music did not flip over to one speaker if I moved that way, as is typical. Instead, I seemed to be able to hear soundstage regardless of where on my couch I sat, the sweet spot being considerably widened.

So what is not to like?

So far, my reactions are all positive but let me add a couple of caveats. The benefits are not uniform across recordings. Using both CD and LP playback, most benefited from the qøl and none sounded worse, but for reasons I cannot explain, I heard little benefit on some classical recordings released early on CD such as the Duetsche Grammaphon box set of Beethoven Symphonies with von Karajan conducting, or on occasional rock recordings such as first generation CD release of Hendrix’s Are You Experienced. Without more time to complete a systematic review of more of my collection, I cannot deduce a cause here or even conclude that certain recording types do not benefit from the qøl (I suspect early digital mastering is one culprit) but it’s clear to me that if you have an extensive collection of music from several decades, the benefits are less obvious on some recordings you will likely own.

With LPs I had the most interesting experience. BSG’s instructions suggest that the “extra information” revealed by qøl might require you to adjust the VTA or your arm. Well, I think that’s a minimum requirement. When I first started playing records with qøl I could not understand what had changed, but my SME table sounded a bit shrill, even though nothing in its setup had altered. I actually spent the best part of a week tweaking everything again to get to a sound I remembered, and it was if I had started from scratch. I even ended up having to adjust the loading on my Whest phono stage as a result of the introduction of the qøl to get it sounding as I wanted. Why was this I wondered? A back and forth with Larry Kay of BSG suggested I might not be alone in this experience and vinyl fans should be forewarned that when trialing a qøl in their own system, they probably won’t be able to rely on the bypass mode to get an accurate reading.

To cut to the chase, I got my vinyl rig sounding better than ever but only after installing qøl and then adjusting VTA and loading. And of course, as any vinyl fanatic knows, you make one change in arm setup and you introduce lots of other variables that need adjusting, if only to be sure, so prepare yourself for this particular trip. Once you’ve done this, you can no longer do comparison with your original pre-qøl sound without changing everything back, which is really not feasible on anything but the most basic or simply-adjusted rigs. However, I consider the end result worth the efforts, as to my ears, even with the qøl out of the signal path, the SME/Clearaudio/Whest combo is sounding as sweet as I’ve known it. Maybe they should market qøl as a great setup tool too!

Adding the qøl into my secondary system produced effects that confirmed what I was hearing with my reference setup. While no sane person would purchase a $4000 product to use with an old Rotel, Naim Nait II and Kef 103.2 setup (a rig with combined ages approaching 60 years!), the qol still managed to clean up the bass, reveal details and otherwise give the old system a new lease of life on Norah Jones’ Come Away With Me and Jim Hall’s Concierto, for example. Bass in particular was more articulated and resolved with the qøl in the system, allowing me on more than one occasion to enjoy private listening sessions in the bedroom without any real sense of being deprived of my reference rig – no mean feat.

Cabling and power cord changes add another variable into the mix. I really enjoyed the High Fidelity cables I reviewed in the June issue, and even though they are single ended, a pair of runs from preamp to qøl and from there to my Spectron monos gave me perhaps the best sound of all, suggesting the qøl does respond to interconnects, as you would expect of any decent component. Power cord changes however seemed to add less. I routinely ran this component with the stock cord connecting it to my PS Audio P5 line regenerator and noticed less significant improvements by using more expensive cords from Pangea or PS Audio that I had to hand, though I did not systematically manipulate this across all cords in my house so it’s possible others might have worked differently. To be honest, the quality of sound I was hearing with the stock cable in the mix left me satisfied and lessened my motivation to keep changing. I think the Pangea AW9 tops it slightly and at its low price is an easy recommendation but I am not sure I’d spend much more to replace the cheap cable that comes with the qøl.

I suppose the ultimate question is if the qøl sounds somehow unnatural or exaggerated. Here’s where I suspect many people’s views will be divided. What I hear with the qøl in the chain is definitely pleasing to my ear. The frequency extremes are better articulated, instrumental lines are cleaner, timbre is enhanced and the soundstage is improved. In my world, these are positive attributes, but I am reminded of how many times I’ve heard people talk of tubes giving us pleasing harmonic distortions, a smoothness we enjoy but which are distortions none the less. I am also reminded of the claims in some forums that other products such as the FM Acoustics Harmonic Linearizer or the Neve Stereo Field Editor are equivalent to the qøl, though I have no way of testing either at this point. I will reiterate the BSG line that the qøl does not involve digital processing or provide you with options to adjust the sound to your taste. You insert it and turn it on, and you get what you get, no tuning or tapering controls involved. In other words, this is not really comparable to any existing processor on the market. For those more concerned with truth than beauty, there’s plenty to think about here but at the end of the day, it’s all about the enjoyment you get from your system.


If it sounds like I enjoyed the qøl, it’s true. Despite my reservations, and my longstanding distaste for add-ons or “enhancers”, here’s one that offers many positive sonic advantages and few, if any, disadvantages. Of course, it is not cheap, and it requires yet another pair of decent interconnects and, if only to keep audio nervosa at bay, an upgraded power cord, so the total cost really is over $5k before you get to play, and that, for many people, will be all they need to know in order to reject it. I cannot argue with their position nor would I, but to my ears the qøl is a substantial component in its own right that you could view as offering an upgrade to everything in your rig.

I wish I understood better the BSG descriptions of what it does, and I do wonder if there is some trick here that will be revealed in due course to have duped me, but I suppose that concern is more a reflection of my own discomfort with an additional, non-traditional component than anything else. After all, I am no expert on how one digital player can read a pit better than another, why some coil windings effect cartridge sound, or how a power cord can have any effect on sound, but that does not stop me enjoying and appreciating the differences where I hear them.

The proof of the pudding with any component is if you want to keep it as part of your rig or if you are willing to give it up. For me, giving it up is not an attractive option, the qøl makes my rig sound better. Just before completing this review I took it out for two weeks and then put it back in again. Without, my system still sounds very good and I had few complaints, but as soon as I put the qøl back in, I knew for sure that life without it leaves me wanting something more. I want one.


Frequency Response 10Hz- 50KHz +/- 0.25dB
THD + N (6Vrms input at 1KHz)(20-20KHz) <0.001%
Max Signal to Noise (20-20KHz) >106dB
Common Mode Rejection Ratio >84dB

Balanced Input Impedance 48K ohms
Balanced Maximum Input Voltage 10Vrms (+22dBu)

Unbalanced Input Impedance 20K ohms
Unbalanced Maximum Input Voltage 5Vrms (+16dBu)

Balanced Output Impedance: 50 ohms
Balanced Maximum Output Voltage: 10Vrms (+22dBu)
Unbalanced Output Impedance: 10 ohms
Unbalanced Maximum Output Voltage: 5Vrms (+16dBu)

Phase Inverting: NO

Inputs: 4 pair, each both Balanced (XLR) and Single-Ended (RCA)
Outputs: 2 pair, each both Balanced (XLR) and Single-Ended (RCA)
Power Consumption Weight (unit only) 15 watts (3 watts when idling) 17.0 lbs. / 7.7 kg
Dimensions (H) x (W) x (D) Shipping Weight: 22.0 lbs. / 10 kg
Price: $3995, 30 day home trial.
BSG: http://www.bsgt.com<

Associated Equipment

Digital-PS Audio PWT/PWD digital front end combo, Rotel 945AX,
Analog-SME 20/2 w/ SME309 arm, Clearaudio Concerto, Whest 0.3RDT phono stage

Preamp: SMcAudio VRE-1, version 1
Power amps: Spectron Musician III Mk 2 bridged monos with Bybee upgrades
Integrated amp: Naim Nait II
Speakers: Von Schweikert VR5SE, KEF 103/2
Cables: Elrod custom made speaker cables, home made 14awg, Spitz Anti-Cables, Grover Huffman XLR, High Fidelity RCA, Harmonic Technology 1.4a HDMI.
Power Cords and Conditioner: Wywires Silver Juice II, Pangea AWG9, PS Audio Prelude, Grover Huffman power cord, PS Audio P5 Line Regenerator

Manufacturer’s Comment

BSG Technologies, LLC wishes to thank Hifi’Zine and Patrick Dillon for a wonderful review of our qøl™ Signal Completion Stage. We like not only Patrick’s conclusions (which everyone would expect as he liked our product), but the way Patrick articulated what he heard and the musical examples he used to make his points.

So, we have nothing to correct and no need to argue or defend ourselves. Instead, we’ll use this opportunity only to make two other points.

One is quite simple: We’re very pleased to announce that we have received a Notice of Allowance of all our claims from the United States Patent and Trademark Office. Granting of our patent shows that our technology is real and unique. Those who had been asserting that qøl™ is like a Rupert Neve processor or something that FM Acoustics, Hafler, Carver or others invented, are simply wrong! Let’s put an end to that nonsense, please.

The second thing we’d like to do is attempt to explain the technology, although you have to understand that, as is the case with many advanced discoveries, it is not easy to do so without scientific language and math. Still…

Try, just for the sake of understanding, to imagine a world where all of us could hear bass in nature—subway wheels, roaring jets, rumbling trucks, acoustic bass and cello, etc. Also imagine, please, that in that world, some limitation in, let’s suppose, cone materials, made it impossible for speakers to produce bass, even though it had been captured by microphones and was present on recordings. In that sense, the bass was present, but remained hidden and buried in recordings because at that time equipment could not reproduce what the recordings contained.

That world does not exactly exist. But there is a world, the real world, in which important information—information which we hear in real, natural sound events– has been captured and is present in recordings, but has remained hidden and buried in all attempts to reproduce sound using electronics. That information is not bass; it’s the full panoply of phase information. (Phase is a lot more than just polarity, friends.) In nature, phase information is one of the three key components of sound. The others are frequency and amplitude (although magnitude might be a better word). Today, sound reproduction gear does a fine job with frequency and amplitude, but phase information has remained hidden and buried and we have been deprived of hearing it in electronically reproduced sound. The mathematics of our electronics has been canceling it! BSG Technologies did not discover that phenomenon—it’s been known in the scientific and engineering community for a long time, but our inventor was the first to find a way to overcome the cancellation problem.

What then does the newfound ability to reproduce the phase component in audio signals do for us? It gives us all the natural information originally picked-up when the live sound event occurred. We can now get from recordings all the spatial and temporal cues we would hear in nature if we were in attendance at the original sound event—the ability to tell where sounds are coming from, to distinguish without difficulty one sound and its source from another, how near or far away it may be, height and width and depth, the nature (big or small, indoor or outdoor, live or dead, etc.) of the space where the sound was made, the individual space and character of each sound source among many, the sounds” magnitude (mass and volume, not only amplitude), etc. All those little clues that render sound complete, full, natural, real and lifelike are now clearer. And, because the components of frequency, magnitude and phase interact and affect one another, we also get a truer picture of other nuances—tonality, dynamics, transients and everything else. Hence, Patrick heard more separation between instruments, found it easier to distinguish plucked bass from drums, was better able to grasp a “slightly slow swing feel,” better appreciated a musician’s fingering of strings and frets, enjoyed cleaner transient attack and decay, grasped more of the dynamics of music and heard old recordings come to life with renewed energy. To us, this sounds much like the difference between hearing music performed live and music reproduced at home. That’s what qøl™ does—it closes the gap between real sound made in a real space and reproduced sound made in a separate space, exactly what so many of us have spent so much time and money seeking to obtain.

All of that happens because qøl™ enables the reproduction of natural information that has always been there for the taking. None of the information is synthesized, faked or phony. None of it changes the intentions of those who made or captured the sounds when they were occurring in reality—after all, what qøl™ retrieves is part of what they heard in the first place. The sound with qøl™ is not something that has been added, but the retrieval of sound that had been taken away from us. If you know the sound of live instruments, as Patrick Dillon obviously does, you’ll know it when you hear it from qøl™. And our money back offer makes it easy to try it yourself. We hope and trust that, like Patrick, you’ll conclude that you want one.

Happy listening,

BSG Technologies, LLC

Readers' comments

    i too am jaded – after 20 years of listening to the “next best thing” – i cant help but think this product will be out of vogue by late 2013 – if its still in your sytem by september of 2013 then let me know

    if it was $1000 – i would def try it – but are you kidding me – for $4000 ?

    stew margolis

  • I havent heard the device so i dont have an opinion: If it was under $1000 i would try it and im sure many others would – the way its described now – its not enough to get me to want one

    maybe calling it something else would justify in my mind a reason to get this
    cant see spending at least $4000 for a “signal completion device”

    let me try it for 2 weeks for free or for a minimal cost and then if i want it i will pay the money if i think its worth it. just think that laying out $4000 dollars and then asking for my money back seems so awkward

  • just think if people want to spend $4000 – they would rather put that money towards and amp or speakers

    am i off base?

  • Stewart, thanks for the comments.

    I don’t know any company that will ship goods on trial without interested purchasers providing at least a credit card number, just trusting the purchaser to return it or buy it. Such companies would surely lose goods in that model and so they have to protect themselves. For what it’s worth, I have manufacturers who ask me to provide card details before shipping me something for review in the ‘Zine (PS Audio being the latest) and they know I am writing a review, not considering a purchase.

    As to putting the money towards new speakers or amps, agree, for many that makes sense. While I found the qol made a difference to my second rig, I would not be likely to invest $4k there, rather I’d spend the money on new components. However, given my reference rig, I am not sure I can upgrade amps or speakers significantly by trading what I’ve got and just adding $4k to the total price. In this context, the value of the qol takes on a different hue.

  • Seems like the $1,100 DSPeaker anti mode 2.0 will give far more bang for the buck. This device cleans up the base and has many other useful features. I found that it allowed me to increase the volm 2 full clicks because the room induced boom was goooone.

  • Well, BSG has closed its doors. I think that the steep price was a factor, if they would have thrown in a volume control and a couple other features I think it would have sold better as a preamp/scs.

    That being said, I just picked up a like new one for $800 and I’m going to try it out now that the price is right. Any word on why they closed or where they are today?

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