Holy cow! This was an old thread! The QOL can be quite impressive.
ozzy
Review: BSG Technologies Qol Signal Completion Stage Preamplifier
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. (https://www.whatsbestforum.com/threads/stereo-field-processing.4384/) 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? |