March 2002

Conrad-Johnson EV1 Phono Stage

Review Summary Sound "Slightly euphonic," but "exceptionally good low-level resolution and superb soundstaging" too; "dynamics rendered by the EV1 were more in keeping with the naturally recorded events." Features "Provides 49dB of gain by using a single-ended-triode input amplifier comprised of both sections of a miniature twin-triode tube connected in parallel, which "is said to significantly reduces noise"; "input load impedance is factory preset to 47k ohms," but "internal load-selector switches can be set for four other values." Use The ".35 mV output Lyra Clavis wasn’t a very good match," but .60mV van den Hul Frog "was able to bring out the best in the EV1." Value "A perfect companion to the PV14LS line-stage preamp," but "its slightly euphonic but detailed and dynamic sound makes it worthy of consideration for vinylphiles who don't own C-J preamps."

Ah, phono preamplifiers. Are they a necessary evil in today’s line-stage-centric world or an essential component for all analog-loving audiophiles' systems? Both, I'd say. I use a full-function preamp with an exceptional on-board phono section -- not all preamplifiers are line-stage only. Yet quite a few are, and to forgo a decent preamp just because it doesn’t include a phono section would be quite a shame, especially since there are quite a few high-quality, reasonably priced stand-alone phono preamps on the market.

So I guess the raison d’être of the $1495 USD Conrad-Johnson EV1 phono preamplifier is that the vast majority of the preamplifiers available today don't include a phono section. And it also makes sense that since the majority of Conrad-Johnson’s products are driven by "old-fashioned" vacuum tubes, the company should manufacture a phono preamplifier for us "old-fashioned" LP aficionados.

Technical stuff

Conrad-Johnson says that the EV1 is based on the circuit used in their much more expensive Premier Fifteen phono stage. The EV1 provides 49dB of gain by using a single-ended-triode input amplifier comprised of both sections of a miniature twin-triode tube connected in parallel. This parallel arrangement is said to significantly reduce noise. A second single-ended-triode amplifier provides the added gain. A direct-coupled cathode-follower output stage yields a low output impedance that enables proper matching with all combinations of interconnects and line-stage preamplifiers. The EV1’s circuit doesn’t use a negative feedback loop and, according to C-J, eliminates feedback-induced audible timing errors.

Like the matching line-stage preamplifier, the PV14LS, the EV1 uses the "highest quality" component parts, such as precision low-noise audio circuit resistors as well as polypropylene and polystyrene capacitors. Tubes are a pair of 12AX7s, a 12AU7, and a 5751. The single-ended inputs and outputs are gold-plated. Conrad-Johnson stresses that their power-supply design is as important as the audio circuit, and they utilize discrete DC-power-supply regulators to filter noise and fluctuations from the power line and deliver a stable source of DC power. C-J also says that these regulators are carefully designed to deliver the lowest possible AC impedance across the audio spectrum, so that individual gain stages are isolated from one another to ensure there is no interaction between them that might smear transient information.

Setup and use

The input load impedance is factory preset to 47k ohms, which is where I left it, but there are internal load selector switches that can be set for four other impedance values. I plugged the EV1's included power cord into the PS Audio Power Plant P300 and therefore did not experiment with any after-market power cords. I’ve found that after-market power cords make much less of a difference when connected to a PS Audio AC regenerator.

The EV1 does not have a standby mode, but powering up the unit when cold and immediately spinning LPs did not bring out the full potential of the unit. The manual recommends letting the unit warm up for about 15 minutes, but I found that twice that length of time was necessary before the EV1 was ready for some serious listening. While the EV1 was in my system, I would turn the power on in the morning and not switch the power off until the end of the day.

The EV1 measures 14 3/8"D x 19"W x 3 1/2"H and weighs a relatively light 14 pounds. Its sound improved when I gave it its own shelf on the equipment rack and placed a Vibrapod under each of its feet.

Sound off

You would think that 49dB of gain would be sufficient to drive most cartridges, but my .35 mV output Lyra Clavis wasn’t a very good match for the EV1. The background noise generated by the EV1’s tubes along with a slight, but noticeable 60Hz hum intruded on the music. I’m not implying that you can’t use a low-output cartridge with the EV1 -- I had the Clavis hooked up to the Conrad-Johnson for quite some time before I switched to another, higher-output cartridge. It’s just that the background noise became irksome after a while, and I felt that I would be negligent if I reviewed the EV1 with the Lyra Clavis. I had much better results using the higher-output (but by no means high-output) van den Hul Frog, also a moving-coil design. Rated at .60mV, this excellent phono cartridge was able to bring out the best in the EV1. Tube noise was much less noticeable, and the slight hum that was very annoying when using the Lyra Clavis wasn’t completely gone, but it was much less noticeable, especially if the volume wasn’t raised much past normal listening levels.

I used the EV1 with the matching Conrad-Johnson PV14LS line-stage preamplifier ($1995 USD) and with two other preamps: a Balanced Audio Technology VK-3i and my reference Audible Illusions Modulus 3a. I was better able to zero in on the EV1’s sonic personality with the BAT and Audible Illusions preamps because the EV1 has almost the exact sonic signature as the PV14LS. In many respects, this made the EV1 a perfect match for the PV-14LS because its personality was not exaggerated as much as when hooked up to other units. Together the two functioned as a complete preamp/phono stage unit.

Todd Rundgren’s Something/Anything pressed by Mobile Fidelity Sound Lab [MFSL 2-225] is a textbook example of the golden age of analog multi-track recording. The EV1 presented the LP in all its glory. Rundgren plays all of the instruments on three sides of the four sides, including his virtuoso lead guitar, heart-on-his-sleeve vocals, and simple yet capable drumming. I don’t think I enjoyed this album more. Even though its presentation was slightly euphonic, the EV1 offered up the entire recording without ever being overwhelmed by the sometimes-cluttered production.

I listened to tons of classical LPs through the EV1. One of the latest re-releases from Classic Records is the Heifetz version of Sibelius’ Violin Concerto [Classic/RCA LSC-2435]. I don’t think I’ve heard a more convincing rendering of closely miked violin. I think it is important to note that although it might seem as if I’m dwelling on the EV1’s euphonic character, it is only because all its other traits come so close to rendering seamless transparency that there really wasn’t much to describe. Sure, it has exceptionally good low-level resolution and superb soundstaging, along with a crystal-clear midrange that is rendered perfectly grain-free, probably due to its vacuum-tube innards. But its sound was very dependent on the recording. If the album was recorded well, it sounded great. The Heifetz disc is an excellent recording of the solo violin and accompanying orchestra; therefore, it sounded great through the EV1.

What’s often nice about tube phono stages is their dynamic prowess, which was evident when playing the Heifetz LP through the EV1. These dynamics can be very dramatic, yet at the same time very natural. But I don’t mean here just the difference between soft and loud, but rather the difference between two instruments, or group of instruments, that may be playing simultaneously but at different volumes. This also means that the dynamics rendered by the EV1 were more in keeping with those of the recorded event. On a pop record, these may be artificially produced, but on a classical, jazz, or otherwise straightforwardly recorded acoustic program, real humans produce the music in real time. The EV1 was very convincing when these natural events passed through it. For instance, when Heifetz begins to move his bow across the strings, even when the entire orchestra is playing behind him, you can hear the very first microseconds of the act blossom into a phrase with the EV1.

The EV1 cast a huge soundstage. The Todd Rundgren record demonstrated this trait even though this LP could hardly be called an audiophile recording (although it is an audiophile pressing). Still, the Heifetz recording was much better at demonstrating this. The orchestra was spread out behind the star; each section of his supporting ensemble was locked in place, with each individual instrument secure in its position when featured. Sibelius’ orchestration is at the same time both lush and invigorating, and the EV1 was able to bring out all the positive aspects of this early stereo recording.

Another LP that spent quite some time on my turntable during the Conrad-Johnson EV1’s stay was Dead Can Dance’s Spritchaser [4AD DAD 6008]. Now this is a demo-quality record. This LP is overflowing with expertly recorded male and female vocals, instruments pushing the frequency extremes, and exotic percussion. The EV1 was able to pass on all the information to the line-stage with style. All the instruments and vocalists were properly sized, appropriately placed, and had outlines that I could only call natural. These images weren’t pinpoint in the same way many (especially solid-state) components would present them. So at times I thought there was a loss of focus in the way the EV1 presented its images. Yet I also thought about attending a live performance, which I do on a regular basis. The way the EV1 presents images might be closer to realistic. This is because the images were able to be located within the soundstage not only from the sound of the instruments but the ambiance surrounding them.

Comparisons

I had no other outboard phono preamps to compare with the EV1, but the internal phono stages installed in the Audible Illusions Modulus 3a (about a $500 option) and the Balance Audio Technology VK-3i (also $500) were worthy competitors. Even though both phono sections appear to cost much less than the EV1, when you consider that the EV1 has its own power supply and cabinet, I guess you can consider them somewhat equivalent.

The VK-3i’s phono section was so similar in sound to the EV1 that it was sometimes difficult to tell which one I was listening to unless I looked at the selector switch of the preamplifier. Both sounded a bit tubey, and both had a slightest bit of background noise, including a wee bit of 60Hz hum. But both sounded organic in the best of possible definition of the term. Both had an outstanding soundstage, and both reached into the depths of the record grooves to achieve low-level information that was extraordinary. But again, there was still that slight bit of background noise and loss of focus that I spoke of when describing the EV1’s sound.

The Audible Illusions, on the other hand, was better-sounding than both of these units. It's transparent to a fault, dead silent, totally grain-free, and has sufficient gain to drive the lower-output Lyra Clavis DC cartridge. I still struggle to find fault with the Modulus 3a (other than it is a non-remote-controlled, ergonomic disappointment) let alone with its phono stage.

Conclusion

The Conrad-Johnson EV1 phono preamp is a perfect companion to the PV14LS line-stage preamp -- not only cosmetically but sonically as well. However, its slightly euphonic but detailed and dynamic sound makes it worthy of consideration for vinylphiles who don't own C-J preamps. It needs a cartridge with at least .50mV output, I'd say, but once this is the case, the EV1 does justice to all kinds of music, especially classical. Give it a listen.

...Tom Lyle
tom@soundstage.com

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