The Sonic Euphoria PLC

Michael Wright                                                                    April 2004

            What is all the Euphoria about?

One of the great benefits of being an audio reviewer is all of the different companies that you come into contact with. Obviouslyreviewing components from widely respected companies like Conrad Johnson (whose splendid MF2500A amp and Premier 18 preamp I reviewed a while back) is great, but it’s those companies that aren’t yet in the mainstream that make this job so neat. These guys tend to be unpretentious and really are all about the music. We all share a love for music and the means with which we achieve this end. This couldn’t have been any truer than at this past winter’s CES, where I spent a lot of time mingling with manufactures from smaller, mostly unheard of companies.

It was in one of these rooms that I was fortunate enough to come across Jeff Hagler of Sonic Euphoria. He was telling me all about his new Passive Line Controller (PLC) preamp and admittedly I was completely taken with its elegant simplicity which could be seen through the acrylic top on the display model. My only previous experiences with passive linestages had been with Steve McCormack’s Line Drive from the early 90’s and a Placette Audio passive linestage. I heard the Placette piece in one of the local audio shops a while back, in a system that I was not very familiar with and couldn’t really make a value judgment on it. Hopefully. I’ll get to hear it in an environment that I’m familiar with and can report on it to you at a later date. But the Line Drive I had at home for a while and can say my experience with it was mixed. I was not accustomed to the operation and nuances of a passive preamp and did not enjoy it as much as I could have had I been more knowledgeable about what I was working with.

First, let me speak a bit about the generalities and idiosyncrasies of passive linestages. Since there is no active circuitry, they are not suppose to be able to drive long interconnect and even with shorter runs of interconnect you’ll want to make sure the cable is low in capacitance. They also require the use of line sources that typically have high output and they need to be hooked up to amplifiers that have a high input impedance. For whatever reason, after listening to passive linestages, I always felt better off listening to an active linestage afterwards.

But there was something different about the Sonic Euphoria that drew me closer to it. Not only were there no active parts on the inside, but here were dozens and dozens of copper wires that looked as if someone took great time and effort to run each one neatly from the volume and selector switches, to the autoformers and then to the input and output connectors at the back of the preamp. My ears really pricked up when Jeff mentioned that the balanced version of the preamp that he was showing me was only $1,795 and that he also had a single-ended unit selling for $1,195! I started thinking to myself, “Hmmmmm, Cancun may have to wait. I hope the wife likes the Wisconsin Dells.” Jeff invited me to step into the next room and do a little listening and I came away impressed. Track after track came through clean and clear and with impact. My curiosity was peaked and I just had to get one of these passive preamps home for a review. A few weeks later, one arrived. The unit I received was single-ended. I plan on getting a balanced PLC in house and will do a follow up to this review in the months to come. 

The look of Euphoria

The outside of the preamp is fairly minimalist but still has enough going on to catch your attention, trust me. Even though your $1,195 is not spent on any frills or a light show doesn’t mean that the preamp isn’t attractive because it is. Compared to some of the other passive preamp offerings, e.g., Channel Island, FT Audio and even the Placette, you would be very impressed with the PLC’s looks. The faceplate is a 1/2 inch thick brushed aluminum with nice metalwork and come in either silver with silver knobs or black with black knobs.

Affixed to the lower right corner of the PLC is a small label with the name ‘Sonic Euphoria’ on it. There are three knobs on the front of the preamp for source selection, volume control, and a half step switch. The source selector and volume control switches are by Elma. They are precision-made, of very high quality and rated for 25,000 cycles. The action of the knobs is a little stiff but nothing that would be bothersome. The selector switch has six positions that are not labeled so you’ll have to take care to make sure you know which inputs you have your equipment on. Since I only use two inputs, phono and CD, this was not a problem. You folks who will need to use four or more inputs need to make sure you come up with your own system for remembering which piece of equipment is on which input selector position.

The volume selector is a little larger than the other two selector knobs and has 24 positions, each position is in increments of 1.8dB steps. The third, and probably least used knob is the ‘Half Step’ switch. This switch will reduce the volume level by about 0.9dB or ½ the level of a standard volume control step. In the up position, this switch is not engaged and entirely out of the circuit path. In the down position you will experience a slightly reduced volume level. Sonic Euphoria recommends not using this switch unless entirely necessary. The best sound quality is with this switch in the up position and is where I had it for the entirety of this review. If you do want to use or experiment with this switch, do not use it if you have the volume up high or around step 19 (or 20, but who’s counting) because it will not function properly. In fact, to be safe, I would talk to Jeff first to see if using it in your configuration is even necessary. Like I said, I never used it or found the need to use it, you might. The back of the preamp is fairly straight-forward. There are four input connectors and three outputs, one of which is a tape out. There are several upgrade options you can get with this preamp such as a remote control. Another is WBT connectors. They cost $30 per pair for each set of inputs or outputs.

This preamp also employs the use of a grounding cable to ground the chassis. Connect the banana end to the grounding post on the back of the PLC and plug the other end into a standard wall outlet. The power pins are not connected. This method was chosen as an easy way to connect the ground. The purpose of the ground connection is to drain any charges that may accumulate on the chassis and to prevent static discharges from appearing on the audio signal. The right and left signal grounds are isolated from the chassis as well as each other. This is done to assure as much channel separation as possible. The inside of the preamp is unlike anything I’ve seen before. As I mentioned earlier, there are short lengths of copper wire being run inside of the preamp from back to front and side to side, all done very neatly, point-to-point and with what had to be a lot of painstaking care. The connectors as well as all of the switches seemed to be tight, with no play or looseness and all of the places where solder was used were clean and professionally done.

The most prominent feature on the inside of the PLC has to be the two autoformers. As Jeff Hagler explains it, “An autoformer is a simplified transformer, in which the primary and the secondary share the same windings. They generally function the same as a transformer. Since the input and output share they same winding it is a simpler device than a full transformer (this is good), but for the same reason it cannot provide electrical isolation between the input and output. Electrical isolation is good for noise filtration, particularly ground loops. The autoformers are significant in their ability to convert energy between voltage and current, thus yielding current gain during normal operation. Second are the impedance matching capabilities, which can enhance the compatibility of the source to the amplifier. These are two big advantages over resistor/pot based units.” I’ll add here that inside of the balanced PLC are two pairs of autoformers and twice as much of the copper cabling that’s inside of the unbalanced version. This may account for much of the price difference.

The sound of Euphoria

Let me explain something to you before I get into describing how the PLC sounds. Please, whatever you do, do not think of this as just some overachieving $1,200 preamp because if you do, you’ll be cheating yourself big time. In fact, don’t even think about price when reading my description of the sound of the preamp. Friends who came by and listened to the PLC while I was evaluating it guessed prices anywhere from $3,000-$6,000. So let’s just say that it sounds like it’s worth far more than it actually cost. Actually, I did get a kick out of the sheepish grins and looks of amazement when I told them the price.

Sonically, this preamp will hold it’s own with most preamps available, and definitely with any 3-4 times it’s price. Any stereotypes you’ve developed about passive preamps, particularly when it comes to cable length, you’ll need to discard when thinking about this unit. I routinely used 1-2 meter long interconnect between my sources and the PLC and 2-3 meter long interconnect from the PLC to the amplifier and encountered no problems. When I do my follow-up with the balanced PLC, I’ll be sure to report on the effects of longer runs. Most of my listening was done with the volume control in the 1:00-3:00 range, but even then, I experienced no hum, popping, crosstalk, or any sonic anomalies whatsoever. I was getting more than enough volume to drive my Martin Logan Quests (just ask my wife) even when using my Thor T-3000 tube phono preamp. The only time I did have an issue with hum wound up being the ground on my Merrill turntable coming loose, and that was it.

When listening to the PLC, one of the first things you’ll have to get used to is how natural the musical portrayal is. If the character of the rest of your audio system is neutral, the PLC will render music that is clear and without discernible distortions. It has helped me to easily and quickly identify the changes in my system every time I swapped out a piece of equipment or cable. This alone, to me, makes it an invaluable tool in doing equipment reviews. In terms of its performance in the realm of dynamics, high frequency extension and low bass extension and slam, it only seems to be limited by the equipment it’s used with. For example, when listening to CDs with my Sony XA7ES feeding the PLC, the highs were soft, dynamics did not have as much impact as I would have liked and while the bass was extended, it was not very tuneful. I switched to the Cary 303/200 and all was right with the world. Extended yet sweet and airy highs, a close to palpable midrange with dimensionality and bass that was not only deep, but also tuneful. I made another change, this time to the highly regarded Electrocompaniet EMC-1 and it bought me slightly more detail, high end extension and air with bass impact, but was not quite as musical as the Cary. It was still a joy to listen to. I can’t wait to try this player in its balanced mode when the opportunity presents itself (Dave Thomas assures me that balanced, the EMC-1 is without equal).

My most enjoyable listening sessions came when playing vinyl and combining the PLC with the Thor T-3000 phono preamp. The T-3000 is easily the most cherished part of my system and the PLC, having no active components inside, easily let me see why.

The point I’m getting at here is that every time I changed something in the system, the change was immediately apparent. In most cases, the character of the music changed and I could better analyze each components effect on the music. It takes a talented preamp to both control a system while staying out of the way of its sound. 

Musical Euphoria and a comparison

I had the opportunity to listen to a lot of great music through the PLC starting with vinyl. Sonny Rollin’s Tenor Madness [Prestige] contains one of the greatest saxophone vs. saxophone confrontations ever recorded when Rollins and John Coltrane try to one up each other towards the end of the title cut. With the PLC it was easy to tell when Rollins stopped playing and Coltrane began, and vice versa. The track “Walkin’” from Miles Davis’ Cookin at the Plugged Nickel [Columbia] filled my room with the ambience of the live event and Miles seemingly playing his trumpet in between my speakers. I especially liked Wayne Shorter’s sax work and Herbie Hancock’s steady piano, which underscores this piece.

An even bigger treat was to be had on the Miles Davis and John Coltrane album Live from Stockholm 1960 [Dragon] where they play “All Blues” with a verve and passion the Swedes have probably not experienced since. The recording was only okay probably due to some poor microphone set up but the performances were great. On Betty Carter’s Look What I Got [Verve], her warm, full husky voice comes through clearly on the title track. I really got a greater appreciation for her singing style and the uncanny way she phrases a song. On H. Owen Reed’s “La Fiesta Mexicana” from Fiesta [Reference Recordings] which features the Dallas Wind Symphony lead by Howard Dunn, the rousing opening with brass, bells and tympani all come at you at once. The PLC orchestrated this opening with aplomb and sent room-shuddering bass through the excellent Soaring Audio SLC-A300 amplifier (review coming).

Things were going quite smoothly when the Dynamic Design cable company’s Don Smith came by with some of his White interconnect and Silver speaker cables with bass bi-wire cables to see how they would fare in my system. Ohhhhhhhhhhh! Why did he go and do that! The system took a huge step up in musicality, detail and bass impact. Seems the PLC enjoyed receiving and giving via this cable and interconnect. And these aren’t even their best cables, but come from the middle of their line (their more expensive Platinum cables will the subject of an upcoming review). A couple of the more memorable selections we played were “Blue In Green” and “Sometime Ago” from Lee Ritenour’s CD Stolen Moments CD [GRP]. Both of these selections caused me to close my eyes and get taken somewhere while Lee softly plays his guitar. 

Another joy was listening to Tchaikovsky’s Violin Concerto featuring Itzhak Perlman and The Philadelphia Orchestra lead by Eugene Ormandy. Itzhak is one of the true treasures we have in any vane of music and the PLC allows you to hear more of his skill and artistry come through clearly. 

To be totally fair, on a couple of fronts, if a comparison is to be made, it should be with another passive preamp. To my mind, passives like the Placette and probably the Bent NOH come to mind as other worthy competitors to the PLC. But truthfully, the Sonic Euphoria can be favorably compared to some active preamps costing much more as well. This preamp is lively, dynamic, musical and a tremendous steal at its price. I did compare the PLC briefly to my Thor T-1000 linestage, which, bear in mind, is of Mark I vintage. When I switched to the Thor, the soundstage became slightly larger, a little bit wider, and even a bit more musical. I was impressed at how neutral the Thor sounded even compared to a passive design. The high end and midrange performance is exceptional on both in terms of upper frequency information and openness. The Thor has a slightly warmer sounding midrange while the PLC sounded more neutral. At the same time, the Thor did not have quite the naturalness of the PLC on brass and cymbals or the same string articulation on bass or guitars. Both leave nothing to be desired when it comes to low end performance. The bass seemed fuller and had better impact with the Thor, but was slightly deeper and tighter with the PLC. Other than the addictive tube warmth you get with the Thor, all of these comparisons were fairly close which says a lot, I think for the Sonic Euphoria. 

On the other hand, even though I could clearly hear those areas where the PLC may have been better, the Thor was still very musically satisfying and involving. The PLC has caused me to decide to send the Thor in for the Mark II update. It was a classical confrontation between a passive preamp and one that was active. I have to tell you that in my system, the PLC more than held it’s own with the Thor. Tube lovers probably would give the nod to the Thor simply because they love tubes (something I’ve been guilty of in the past). On the other hand, solid-state aficionados definitely would have been impressed that for once, the passive preamp did not get blown away by the active one. If nothing else the PLC shows what a well-designed passive can accomplish when compared to one of the best preamps available.

Winding it down

One very telling experience I had with the Sonic Euphoria PLC was when I had a couple of friends over for a listening session. We were caught up in the listening when I got up to make a change. Almost immediately, one of my friends blurts out that the Sonic Euphoria does have a weakness and that he was able to pick up on it right away. He commented that he felt the music had all of a sudden opened up and that the high frequencies had more air, more information and that the performers across the stage seemed more in their on space on the stage, more dimensional. I had to point out to my friend that I had actually swapped out the Sony CD player and that we were now listening to vinyl. The PLC was actually still in place. He sheepishly smiled and said “I knew that.” The Thor is going to remain my “active” reference as there is just too much magic there not to have one. But the Sonic Euphoria PLC has been such a joy to listen to and an invaluable tool in evaluating other equipment and cables. I liked it well enough to purchase one to use as my “passive” reference. I can’t recommend it any higher than that.