Review: BSG Technologies Qol Signal Completion Stage Preamplifier

Category: Preamps

BSG Qol Review February 2012.

I received my Qol unit late in the day last Saturday via Fed Ex. The Qol unit was very cold when I unpackaged it so I let it rest. Still, I was curious as heck so I did manage to play it for about 30 minutes that night.
I installed the Qol between My Pass XP-10 Preamp and Pass Labs X350.5 Amp. I was fortunate because I had another set of balanced interconnects just like my others and a Synergistic Tesla Power cord just like my others and I even had a 1A spare HIFI Tuning fuse available.

First impression, I thought it sounded kind of bright and with limited, if any, sound quality improvement.
The next day on Sunday, I played the Qol for a while, but again, I thought it was kind of bright sounding. I attributed it to needing some break in time. I then hooked the Qol up to a tuner and continuously played music 24/7 even when I was not actually listening to my music.

Well, I am a little embarrassed to post this but what the heck.
My earlier thoughts about the Qol sounding a little bright and the sound quality lacking turned out to be because I am using way too many speaker tweaks.
I found that the spades of my AudioPrism ground controls were touching the copper body of my Walker HDL Links, (On both L and R sides). In essence it was shorting out. It must have occurred when I was rerouting some of the cabling. Once I separated them the brightness went away, the sound quality greatly improved and the soundstage expanded every which way. I could actually hear that change occur when I was behind my speakers.
I wonder if I should just remove all of my speaker tweaks? Maybe later.

Since then, I have continued to break in the Qol by continually playing music through it. I believe the sound quality is still improving. So, anyone who says it is plug and play is not getting the full potential of the unit. Not sure how long the break in should take but 200 hours seems to work best for most electronic components.

Well my room also has problems that were preventing me from fully enjoying the Qol.
The Qol is certainly a different animal than what I have been used to. The Qol needs open area to do its magic.

So first off, I have had in my room for about a decade Argent Room Lenses.
For those unfamiliar to this room correction item, they are made with 3 pipes attached to a stand called dark matter. Anyway, the pipes are designed to work as a Helmholtz Resonator. There are 3 of these units in the room. Two were flanking the outer side of the speakers and one in the center of the room. These units worked fantastic, especially before my basement dedicated room was finished and I installed defined walls.
The Room Lens captured the side reflections and defined the soundstage.

Anyway, the Qol unit works almost the opposite by expanding the soundstage. So, I removed the Argent Room Lens from the room and played some music, and yes, the soundstage opened up.

The other problem I had was my Eggleston Andra 2 speakers were extremely toed in. The Toe in angle was so much that the image was directed to the center of my head. The music sounded like Olivia Newton John had her tongue in my ear. Not necessary a bad thing, but not correct for the recorded soundstage.
Well these speakers weigh 215 lbs and have 2” Audio Point spikes on them making it very difficult to just change the toe in angle.

I found that Herbie Labs sells a glider designed for Speaker spikes and with this glider I could move the speakers. So I ordered a set of them.

I received the Speaker spike Gliders a few days later and I went about reducing the amount of toe in. After the change, the soundstage became enormous.
I now have my speakers just about at a 90 degree angle and 36” from the side walls. But I will continue to experiment with placement further.

Well now it is almost 7 days later, how does the Qol sound? One of the big benefits of the Qol is the change in dynamics. I mean it is actually hard to find a volume set point to just leave alone. The music can go from soft to loud in a heartbeat. Funny, that even though the music appears to be quite louder, my Pass Labs Amp meter moves very little. This indicates to me that the increased dynamics is not pulling anymore current from my Amp.

With the Qol engaged, the music takes on a natural sound and image. The soundstage becomes very wide and deep. My speakers virtually disappear. I know that is said all the time, and before the Qol I thought my set up was awesome, but with the Qol you can hear deep into the recordings. The center image is the best I have ever heard. I can now hear background singers clearer and my toe tapping has increased.
The frequency extremes are heard with an authority. What I mean by that is that they are no longer buried in the mix but sound like they were part of the intended sound, if that makes sense.
Not all recordings were as hyped up as others. I guess each recording has its own reverb, echo, and different out of phase anomalies.

So the $4000 question, is it worth the money ?...
Well, if you want the deepest, widest soundstage and the wildest dynamics your components can handle, what price is that worth to you?
For me, it’s a keeper, no question.

Associated gear
Click to view my Virtual System
I see Lions paraphenalia? Are you in Detroit? I'd like to hear that QOL unit in action.
I read a review of the BSG Technologies QOL in the February 2012 issue of The Absolute Sound. It was an interesting review. I hope to try one of these in the near future. Your review is similar to that of Robert Harley’s. I hope to listen to the effects of this item in the future. It is not inexpensive, $4000, but if it does what it claims to do, I’m willing to save up for it.

Thanks for the review of this item.
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I had a recent experience with the QOL for several days in my triamped system (Magneplanar MG20's plus Hsu tower subs, tube electronics, VPI Classic, C-J cd player). I really didn't want to like it, but that didn't quite pan out.

I agree with most of Ozzy's conclusions, but might add:
1--defeating the circuitry with the bypass sounds murky compared to taking the thing out of the system entirely, so A-B comparisons go way in favor of qol.

2--Simply put, my system never sounded as good. Major improvements in spatiality, dynamics, fine detail, and liquidity were not subtle. The bass (a fetish of mine) became focused and the pitch much more precise. Voices "floated" with an ethereal, almost ghostly, quality that was quite sexy. The image size was MUCH larger, and I could definitely hear material coming from in BACK of me--a first. The stage goes WAY past the lateral borders of the speakers, even more so than usual.

3--There is a qualitative difference that is tricky to characterize. The music made me "happy" in a way that has become rarer as I have become older. It's as if endorphins have been triggered and the musical pleasure centers energized. It feels really, really good. I can't guarantee that this will happen to you, but my friend who lent me the unit knows exactly what this is about.

4--If your musical experience is 30% better with qol, your system need only cost $13K for the admittedly high price of 4K to be justified.

Who knows what the future will be for this circuitry or for BSG? There's no doubt they could sell more at a lower price point. The unit is way overbuilt, with balanced AND single ended inputs numbering 4 and outputs 2. Add a volume control, and it's a preamp, but make it simpler and the price could go down. Will licensing agreements materialize for this company? Will a competing technology become available for hundreds rather than thousands? I'm not sure I can afford to wait for these questions to be answereed. I'm on the verge of ordering one

Hey Ozzy,

My review on the QOL stage was just put up on the website were I came to a completely different opinion then yours about the performance of this device. It pretty much did nothing postive in my system and I gave it every chance I could to produce just a little magic and it was not happening. Frankly, I can't see why anyone would lay out 4K for this do nothing device.
Teajay, I just read your review. There MUST be something wrong in the unit you had or there is something quite unique with your system (good or bad).

You should have heard a huge difference.
It is a huge improvement in my audio enjoyment.

True $4000 is a lot of money for the Qol, but many of us spend that on speaker cables. And to me, there has never been this much improvment with any cable change I have made.
And for that matter any Preamp or CD Player upgrade either.
Hi Ozzy,

You also could claim I'm deaf if you want, however two other experienced listeners in two different very good systems had the same experience I did. What I did not put in my review is what I consider the most bogus aspect of the SCS, that when it is engaged it increases volume from anywere from 2db to 4db depending on the recording which any seasoned audiophile knows will either at first either sound different/better compared to a lower volume. If you match the volume between the bypass and the active circuit you hear no difference at all. When this was mentioned in another review BSG Technologies suggested leaving it the active mode, not going back and forth to compare, because the active stage really was not raising volume, but giving more information that is experienced as an increase db.Please give me a break! If you like what it does in your system that's the most important thing, and yes anyone can try it for 30 days at no risk. I personally would not use it in my system.
I just picked one up and i was wondering... But this ain’t no Carver C9 on steroids! it’s something else...I like it! I’m glad i didn’t shell out 4K.

I picked up a BSG Technologies QOL Signal Completion Stage from a fellow Audiogon Market participant a couple months ago after waiting for ten years to find out what they sound like. The sound of my system is now among the best that I have heard anywhere! Although the impact of the QOL varies, depending on the recording, I find that when listening to small, acoustic performances, that I can ’hear’ the reflecting walls of the studio, or in live performances, the venue’s stage. (I am a former performance musician and know how it should sound.) Moreover, the sense of ’acoustic space’ surrounding the performers was realistic, and the soundstage extended beyond the physical width of the speakers, with orchestral recordings sounding majestic. Listening to the Beatles’ Magical Mystery Tour LP mono release, the QOL Mono functionality enhanced the depth of the recording substantially, but still sounded natural.

The previous owner strongly suggested that I place the QOL between the source components and the preamplifier, if using a vacuum tube preamp. Since my McIntosh C2300 is indeed a tube preamp, I ultimately followed the advice offered, sounding much better than when placed between the preamp and amplifier (the recommended connections in the manual), I found.

During my setup and testing, one of the sources I used was the Carver CD-4000 Sonic Holography(TM) Demonstration-Calibration Test Disc (1988), which also contains many, non-Sonic Holography test tracks. The QOL is DEFINITELY NOT Sonic Holography, but they are similar in that they both use phase processing to enhance the signal, although very differently. Forgetting to switch the QOL to BYPASS during setup, I coincidentally found that using the test signals designed for Sonic Holography setup worked quite well for aligning the speakers for optimal QOL playback with music - Very Interesting.

In a dissenting post, Paul Wilson (Audiophile Review), "How Eliminating A Component Improved My System's Sound" states he removed the QOL from his system after a mastering engineer explained to him how the signal is manipulated to achieve the sound, with Recording engineer Bruce Brown stating "I was listening to its [QOL] effect and found I could recreate the same exact effect by using the mid/side settings on my console. It does increase gain and brings up all the "side" information from about 125 Hz and above. I had put an SACD in my Playback Designs and also had the ripped DSD information in my Sonoma workstation and going through an analog loop from the console. I matched the gain and did quick A/B comparisons to see if I could [sic] emualte the effect. Anyone could do the same exact thing using a L+R/L-R/Mid algorithm." The problem with both engineers' comments above is that they are describing what's done in the production of a new recording by individually manipulating components of active signals, while the QOL works on fixed playback signals from existing recordings from various media sources 'automatically,' without operator machinations. (

Virtually all of my recordings sound better (some more than others, naturally), with recently acquired SACDs of recordings previously owned on CD sounding remarkable (perhaps due to their enhanced resolution), but sonic improvements in all sources are audible, even when listening to FM broadcasts (I do not listen to streaming audio, however).

I’m sold on this product, and amazed that no manufacturer included the QOL functionality into a preamp or other device, which was the inventor’s ultimate goal. Now that the product is gone, the company out of business, and the technology seemingly dead, does anyone know where I can get a schematic for the unit?

I recorded many of my Live recordings using the QOL and even today when I play them back, I am greatly impressed with the wide-open soundstage.

Too bad the design did not include volume adjustment then it could have replaced a preamp, instead of adding another piece of equipment to the chain.