Although you may think your audio system is being fed perfectly clean power from your listening room's receptacles, this is almost never the case. Besides often wildly-varying line voltages courtesy of your local electric company, the power available to your system is often contaminated with sonically degrading grunge in the form of Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI). As if that wasn't enough, your audio system may be subjected to potentially-damaging voltage spikes from appliance motors or even direct lightning strikes! How is an audiophile supposed to protect his sizable investment and keep his system sounding good amidst this electronic assault? An AC line conditioner may be just the answer, as these devices are designed to filter the power feeding your audio system, reducing RFI and EMI and squelching voltage spikes before they reach your delicate components.
I recently had the opportunity to audition the Power Wedge 114, an AC line conditioner from Audio Power Industries, and thought I would share my initial impressions of this product's sonic impact on my reference system.
While the folks at API may demur, I decided to assess the impact of the Power Wedge 114 on each component of my system individually rather than conditioning all components simultaneously. This was done so that I could determine which components were positively affected by line conditioning and which were either unaffected or negatively affected. Although conditioning only a single component will still leave the system somewhat vulnerable to noise infiltration, if a sonic improvement is heard while a single component is conditioned, this improvement should only be amplified when the entire system is conditioned.
During all auditioning, the Power Wedge 114 was plugged directly into one of two dedicated 15 amp outlets in my listening room.
I started off by assessing the impact of the Power Wedge 114 on my power amplifier, which was plugged into one of the 114's four high-current outlets. The high-current outlets are specifically designed for components like power amplifiers, that are required to draw large amounts of current.
Listening to Aaron Copland's An Outdoor Overture (Reference Recordings), I immediately noticed that the high massed strings sounded a bit muted and macro dynamics suffered in relation to the unconditioned amplifier. The usually-powerful timpani whacks and brass blasts on this recording lost some of their impact. I listened further to see if these impressions were consistent across recordings and indeed they were. The usual impact and gut-wrenching intensity of Shostakovich's Symphony No. 8 (Teldec) was missing in action. This was definitely not the eighth symphony that I knew and loved.
Maybe not surprisingly, the Power Wedge's effect on my amplifier was more positive on small scale jazz and chamber works, during which, I assume, the amplifier wasn't required to draw large amounts of current from the wall. With the Power Wedge, left hand piano lines on naturally-miked solo piano recordings were better resolved and easier to follow. That notwithstanding, on most of the discs I auditioned I preferred the sound of the amplifier when powered directly from the wall socket.
I experimented a bit with my preamplifier - first plugging it into one of the 114's source component outlets and then, on a tip from a local audio dealer, plugging it into one of the high-current outlets.
Using the source component outlet, I noticed that there was a significant improvement in the system's low-level resolution as the noise floor dropped appreciably. I hate to use the tired black background cliché, but sounds did emerge from a blacker background than I've heard in my system before. Massed strings on the Copland disk were silkier and lost the slight metallic edge that they sometimes had with the unconditioned preamp.
Interestingly, these improvements were even more obvious when the preamplifier was plugged into one of the four amplifier outlets, although I'm not entirely sure why this should be the case as preamps aren't generally very current hungry.
While I know that turntables can be very sensitive to the quality of the AC being fed to them and I've heard the not-too-subtle improvements that high quality power supplies like the Linn Lingo can have on the Linn LP12, I wasn't quite ready for the sonic improvement that I heard when my LP12 was conditioned by the Power Wedge. Listening to Paul Simon's You Can't Run But from the Rhythm of the Saints LP on the conditioned LP12, I was amazed at the improved palpability of Simon's voice and the ease with which I could follow the distinct rhythmic instruments employed on this track. The sonic differences I heard between the conditioned and non-conditioned LP12 were so dramatic that I had to employ a neutral third party to verify that I wasn't having some kind of audiophilia-induced hallucination. An informal blind test conducted on my wife confirmed that the improvements were real, as she consistently preferred the sound of the conditioned LP12 and, like me, was quite awestruck at the magnitude of the improvement. Frankly, after hearing the conditioned Linn it was hard to go back to listening to it being fed from vanilla AC.
After hearing the Power Wedge's positive impact on the Linn LP12, I expected similar improvements to my digital front end, but alas, it was not to be. While I noticed that well-recorded female voices were surrounded with a tad more air with the conditioned front end, the benefits of the Power Wedge in this context were subtle at best.
During my initial time with the Power Wedge 114, I noticed that it emitted a considerable amount of transformer hum. While this was rarely noticeable from my listening seat (approximately ten feet away from the Power Wedge), this could prove bothersome, during quiet musical passages, to a listener sitting in close proximity to the device.
My initial time with the Power Wedge 114 was quite enjoyable and educational. Although
I preferred the sound of my system with the amplifier unconditioned and my digital
front benefited only minimally, the 114's positive effect on my preamplifier, and
its enormous effect on my Linn LP12 left me with a positive impression. I hope to
have the opportunity to spend more time with the 114 in the near future, and will
report my findings in an upcoming issue.
Analog source was a Linn Sondek LP12, fitted with an Ittok LVII tonearm and a Linn K9 moving magnet cartridge. Digital source consisted of a Theta Data Basic II transport connected to the excellent Theta DS Pro Progeny DAC with an XLO Type 4 digital interconnect. DAC and turntable were connected to a Conrad Johnson Premier II via a Transparent MusicLink interconnect. Amplification duties were handled by an Aragon 2004 Mk.II amplifier. Amp and preamp were connected via an MIT MusicChord interconnect.