BSG Technologies QOL “Signal Completion Stage”

BSG_Technologies_QOL_review.jpgI have been reading information about a so-called cure-all device on several different audiophile websites for over six months that, when it is inserted in between your source and preamp or in between your preamp and power amps, it would work “magic.” The reviewers also claimed that it would profoundly improve aspects of any recorded music. The list of improvements would include richer, more natural timbres, a bigger as well as more three dimensional soundstage, and add a sense of air and space around different players. The editor of one of the most highly regarded high end journals wrote a review on this “magic box” and stated, “… produces a sound that I think is closer to that of live music.” The name of this device is the QOL “Signal Completion Device” which sells for $3,995.00 and is manufactured by BSG Technologies. So, you can see why I was very intrigued to see if these wonderful sonic changes would happen if I inserted the QOL Signal Completion Device in my system.

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The QOL Signal Completion Device is well built with a silver face plate weighing 25 pounds, having a width of 17 inches, depth of 13 inches and a height of just over three inches. The front panel has six flat buttons for selecting different inputs and a bypass option. The rear panel has four sets of inputs and two sets of outputs, each both RCA and XLR, along with the AC mains inlet and AC power switch. It comes with a remote control so you can engage the active processing or bypass the circuit completely from your system. BSG Technologies stated that they have developed a patent pending technology that is able to recover previously hidden fundamental elements of sound that is buried in all audio signals. Also, they claim that it retrieves and restores this information, producing more realistic and natural experience of music. The QOL Signal Completion Device uses a playback process that is supposed to restore the natural phase relationships in audio signals. I will not pretend that I really understand their theoretical explanation for how this device works. However, I surely could use my ears to see if it brings the sonic changes that BSG Technologies claims it will produce in any system.

The unit sent to me by BSG Technologies was a demo fully broken in. I inserted the QOL in both suggested positions in my system. In one position, I placed the QOL in between my source gear and the preamp. In another position, I placed the QOL in between my preamp and mono block power amps. From either position, I could not find any difference in sound quality, whether it be positive or negative, in my system.

Over the course of a lengthy auditioning process, I used a wide variety of music. Some of the recordings were well recorded, while others were of average sound quality, and paired the QOL with two very different types of speakers. One speaker was a pair of MG-20s which are planer panels, along with a pair of Cellos which are a ported box enclosure design. To be quite frank, the results were very disappointing based on having high expectations of what I assumed would be a qualitative shift to higher level of performance in my system. Yes, on some recordings there would be slight changes in the soundstage regarding the position of some of the instruments. Was this a step towards a more natural spacing between players? My experience was that it just was different, not necessarily more accurate or natural. Regarding timbres or overall tonality, I did not find that the QOL Signal Completion Stage rendered an improved richness or more natural tonal qualities. On some recordings I found that the QOL Signal Completion Stage actually dried out the tonality of some instruments and took away some of the liquidity I normally have in my system. As an overall perspective on what the QOL Signal Completion Stage did in my system, I found that it did very little most of the time and occasionally, on certain recordings, got in the way of the natural ease and relaxation that is part of my system’s overall sonic presentation.

Read about the high points and low points of the QOL on Page 2.

BSG_Technologies_QOL_review.jpgHigh Points
• The QOL Signal Completion Stage is built to a high quality.

The QOL Signal Completion Stage’s remote control allows easy and
convenient bypassing to be able to determine if what it is doing is
something you find beneficial in your system.
• BSG Technologies
offers a risk-free 30-day home audition period. If you decide that it
does not make the improvements you are looking for, there is no finance

Low Points
• The QOL Signal Completion Stage did not render consistent improvements in the areas of timbres, sound staging or dynamics.

The QOL Signal Completion Stage on certain recordings actually changed
some of the tonality towards a less natural presentation.

Competition and Comparison
QOL Signal Completion Stage is a qualitatively new technology so it
cannot be directly compared to other signal processing devices such as
DSP systems or broad band equalizers. That, and I’m not certain what it
does, if anything, thus any comparisons would be unfair to outboard DSP
devices and/or chip sets. While I don’t use Audyssey or similar
devices/programs in my reference set up it’s still sad to think that a
pre-packaged bit of software in many of today’s AV receivers can have a
more positive effect than a so-called audiophile cure-all in the QOL
Signal Completion Stage.

In the context of my
system, the QOL Signal Completion Stage performance fell far short of
the stellar positive changes reported by many consumers and a few
professional reviewers. Based on my experience of QOL Signal Completion
Stage, it would not be a piece I would invest in for my system. Is it
possible that my negative experience with the QOL Signal Completion
Stage could be system dependent, and it might work some of the “magic”
others report in their systems? If you’re still curious if this device
might dramatically improve your system’s performance, remember, BSG
Technologies offers a 30-day risk free home audition period. For me I’m
packing it up and sending it back for I wouldn’t spend $4.00 let alone
$4,000 for it.

Additional Resources
• Read source component reviews from
• Explore reviews in our Stereo Preamp Review section.
• Learn more in our Amplifier Review section.