Conrad-Johnson Classic Sixty-Two SE Stereo Amplifier
by Mark Blackmore | July 31, 2017
© www.theaudiobeat.comMy first audiophile purchase was a used Conrad-Johnson MV50 amp, which delivered 45Wpc from four EL34 tubes. Some years later, it was factory upgraded to MV52 status, which eliminated the electrolytic capacitors in the power supply. That amp began my journey deep into all things Conrad-Johnson. Next up was a PV7 preamp that eventually was traded in for a PV12. Digital audio came from a DA2B tubed DAC and DV2B tubed CD player. I even bought a Sonographe SG3 turntable, which was designed and manufactured by C-J, to complete my obsession. These Conrad-Johnson components were all made before 1995, so, while I'm favorably biased towards C-J gear, I haven't had any of the newer products in my system in over 20 years. I should note that I still have my C-J gear and still get it out from time to time, to refresh my aural memory and enjoy some good sound and feelings of nostalgia.
Conrad-Johnson has recently introduced new Classic-series amps: the Classic Sixty-Two and Classic One-Twenty. Both use EL34s, with 6922s doing the inverter and driver duties. The Classic Sixty-Two is a spiritual descendant of my old MV52, but it outputs 60Wpc from four EL34 tubes, and the Classic One-Twenty doubles the number of output tubes and the power to 120Wpc. Each Classic amp is also available in Special Edition (SE) versions.
What makes the SE amps "special"? Lew Johnson outlined three main points. One, the switch from EL34 tubes for the standard amps to KT120s for the SE. You cannot simply substitute KT120s for the EL34s of the standard Classic amps, because the bias circuit isn't correct. Johnson feels that the KT120 is more dynamic, with a fuller sound and better control in the bass. Second, the SE amps are treated to Teflon capacitors. The coupling caps and caps in the inverter stage are upgraded to Conrad-Johnson's CJD Teflon. Johnson says this improves image focus and yields a more extended treble range that is also sweeter. Finally, critical resistors are upgraded to Vishay bulk metal foil in multiple spots of the circuit for an overall purer sound. The standard Classic Sixty-Two costs $4250 and the upgrade to SE level will take you up to $5750.
The Classic Sixty-Two SE has an attractive lowboy case with powder-coated transformer covers and the signature champagne-colored face plate. The only interfaces on the face plate are a sturdy on/off rocker switch and a red power-on LED. The top of the amp is silk-screened to indicate where to install each of the supplied vacuum tubes, and biasing information is printed in the center. The back panel has an IEC power inlet, RCA input jacks, and a single set of speaker binding posts that were factory set for 4-ohm output to provide a good match with most modern speakers. Sixteen-ohm outputs are possible with an internal rewiring, which might be a good match for those of you owning vintage 11- or 16-ohm versions of the LS3/5A. My Altec Valencias are 16 ohms, but Lew Johnson said because of their high sensitivity, they wouldn't suffer from a bit of power reduction using the supplied 4-ohm taps.
Just like my old MV52, the Classic Sixty-Two SE uses a small-diameter, non-conductive screwdriver to adjust the bias. Turn the adjustment screw clockwise until the corresponding bias LED lights, then counter clockwise until it just turns off. During my two-month listening period, I had to rebias just once, and it took all of 30 seconds to get the amp back to spec. A sturdy tube cage with captive spring-loaded hold-down screws is provided to protect pets and young children from the heat of the output tubes. The SE amp looks good with the cage on or off, but I always use a cage on review equipment in case my two cats develop an interest. Biasing is still a fairly easy job with the cage on, but I recommend a small flashlight to help you see the bias pots when using the supplied plastic screwdriver.
Break-in or, "playing in" as Lew Johnson put it, is real with the Classic Sixty-Two SE. The factory burns in the amp for 48 hours, but you'll need an extra 100 hours for the Teflon caps, and Johnson recommends 100 more hours to complete the process. As one who has endured Lowther and Fostex full-range-speaker break-in, I was prepared for the worst, but this amp posed no problems. The Classic Sixty-Two SE will begin its break-in process by sounding nice and polite followed by a period of thinness. Johnson said this is typical of the Teflon caps, and it was short-lived. Then, at the end of the process you'll hear it: a music selection will sound great and you won't be able to wait to hear another. It is rather obvious, but it can sneak up on you, so keep track of your time.
A couple of practical pointers on break-in. Most audiophiles have an extra pair of speakers that they can use for the process. (Don't ask how many I have.) I hooked up a vintage pair of Large Advents to the Classic Sixty-Two SE and used Tidal playlists of music I wasn't familiar with. This kept me from prejudging the sound, and the Advents gave the amp a less-sensitive speaker to work against. Another suggestion might be to use the amp for TV sound while you're in the break-in period. I'm not very critical of the sound on my usual video diet of DIY home shows, auto repair, and cartoons, so that would work out fine for me.
How did the amp sound after it reached the magic 200-hour mark? The soundstage was wall-to-wall with good depth. Center images were behind the speaker position and were precisely placed in the soundstage. The treble was extended and sweet, as Lew Johnson had predicted, and well integrated into the overall sound. The bass was more rounded than that of my reference amps, but in a way that seemed as musically true. An automotive analogy: the Classic Sixty-Two SE was more about torque than horsepower. It didn't slam me in the chest with bass, but crescendos were exciting and the amp never ran out of power. There wasn't a hint of tubey midrange that would thicken male and female vocals.
If you stopped reading right now, that description would apply to any number of amplifiers you might audition. But the Classic Sixty-Two SE's sound was much more complex. If my old MV52, with its EL34 tubes, could be described as musical, with a velvety tone and a gentle roll-off at the extremes, the Classic Sixty-Two SE was a musician's amplifier. It was a neutral partner, highlighting musical lines with a clear view of the artist's expression. Audiophile talking points didn't enter the picture, as my mind focused on the composer's skill, the engineer's recording choices, and musician's technique. The clarity and speed of the upper midrange and lower treble may have had a lot to do with this.
I'm happy to see Wilson Audio using "Liberty Fanfare" from Winds of War and Peace [Wilson WCD-8823] at recent shows. I performed this piece recently, and the third-cornet part doubles the melody with the horn section. My take on this doubling has always been to soften my own sound and make it more diffuse to mimic the horns. When conducting a concert band and the music calls for trumpet and horn doubling a melody, I ask trumpet players to add presence to the horn melody, not compete with it. The Classic Sixty-Two SE made it plain that this was also happening in the Wilson recording. The cornets were used as equal partners and could be clearly heard as a separate melody line instead of fitting into the horn sound. While I won't change my approach to this piece, it was interesting to hear these two lines sound separate and distinct.
Madeleine Peyroux's wonderful recording Secular Hymns [Verve 5701701] begins with a duet version of "Got You on My Mind." Even though I'm sure this was well rehearsed before the recording, Peyroux and Jon Herington sing as if it were part of a spontaneous concert in my living room. Peyroux almost always begins a verse ahead of the beat and then will ritard -- slow down -- toward the end of the phrase, to let Herington finish first. It comes across as perfectly natural and loose, just like two friends sitting down and singing a favorite tune for you. Again, the C-J amp revealed this seemingly small though important detail, and integrated it into the music's very fabric.
On to another female vocalist whose intent the Classic Sixty-Two SE laid bare: Anne Bisson, who was new to me. I've heard her work through friends, and I noticed she was performing at this year's TAVES show in Toronto. I've become a big fan of her songs, her writing skills and the way her piano has been recorded. Favorite tunes would include "Little Black Lake" and "September in Montreal." On all of these, the percussion was balanced just right and the piano was clear and bright. Unfortunately the Classic Sixty-Two SE also drove home that she and I certainly differ in our sense of pitch. I'll leave it at that, but in all fairness, her 2016 release with Vincent Belanger, Conversations [Camillio 2022], is altogether better in that regard, and I recommend it highly.
Finally, there was Eric Bibb and Habib Koité's 2012 release, Brothers in Bamako [Stony Plain SPCD 1362]. Listen to the jerky, percussive banjo technique on "Khafolé." Habib plays in perfect time per measure, but some notes are ahead or behind the quarter-note pulse to add rhythmic tension and interest. Now compare that style of playing to that of any Nashville banjo player who performs with almost mechanical perfection. Koité's banjo performance is a mixture of harmonic and rhythmic structure that propels the song and is wonderfully played. This recording became a favorite of mine during the wet and dreary Missouri spring.
The Classic Sixty-Two SE nailed Bibb's voice, which just jumped out the speakers and into the room. Why can't more recordings treat the voice this well? Every listening session brought similar insights. I couldn't concentrate on the normal checklist of sonic traits that audiophiles like to discuss. Instead, I would hear tape splices in old recordings, metal mouthpieces on bari-sax solos instead of hard rubber, the tonal beauty of Maurice André. At this point in my audio journey, I am looking less for aural thrills and more for musical connection. The Classic Sixty-Two SE succeeded at this nicely.
Concerned that I should try a conventional speaker with the Classic Sixty-Two SE, I packed up the amp and took it to Kent Johnson's house. Kent recently retired from reviewing at Positive Feedback and has a nice listening space featuring Revel F208 speakers driven by Primare electronics fed by an Esoteric universal player. At 250Wpc, the Primare amp has no trouble controlling the Revel's dual 8" woofers, but could the Classic Sixty-Two SE keep up? After a brief listening session to acclimate our ears to the sound, we swapped out the Primare for the C-J amp. I knew we wouldn't have as much ultimate volume moving from 250 watts to 60, but neither of us listen too loudly, so my fears weren't warranted. I was pleased that the Classic Sixty-Two SE sound was instantly recognizable and similar to my initial reactions after break-in. The soundstage grew wider and taller, vocals moved back behind the plane of the speakers and the bass was more rounded, lacking the Primare's snap and slam. We enjoyed a number of SACD and CD selections, and we both felt the amp would do well in a variety of systems. Except for a touch of hum that we didn't take the time to fix, I was happy with every aspect of the Classic Sixty-Two SE's performance and pleased that it was such a good match for the Revels.
A few months ago, I reviewed the McIntosh MC75 monoblocks, which offer slightly more power, 90 watts, than the Classic Sixty-Two SE, at a slightly higher cost, $7500 per pair. That extra power was instantly noticeable. While the Classic Sixty-Two SE was more than adequate for my listening levels, the McIntosh amps were more forceful with crescendos, loud passages being more effortless, and in the bass. That was the best thing about MC75s' sound. Throughout the midrange and lower treble, where the music really lives, I preferred the Classic Sixty-Two SE for its purity, vividness and natural instrumental tone, which grabbed my attention during every listening session. There was also a larger, better-defined soundstage that the MC75s couldnt match. Treble energy from the two amps was similar, with the Classic Sixty-Two SEs sweeter treble tone being more to my liking. As much as I admired the McIntosh amps, I was compelled to listen to the Conrad-Johnson amp. It held my attention, urging me to listen longer.
At the beginning of the review I called the Classic Sixty-Two SE "a musician's amplifier." I have only a few musician friends who could afford it, but many more should put it on their list of gear necessary to further their art. It has enough power for a variety of speaker loads and has an insightful approach to reproducing music in your listening room. After boxing it up and sending it back I missed its nuance and direct connection to the performers. Reintroducing my reference amp brought a richer tone and a bit more air on top, but it does not give me the same feeling of intimacy.
For those of you who already own Conrad-Johnson gear, many older units can be upgraded to incorporate the CJD Teflon caps, and I am seriously considering that upgrade for my MV52. If it can bring me closer to the performers, as the Classic Sixty-Two SE did, it will be a tremendous upgrade.
Warranty: Five years parts and labor.
Conrad-Johnson Design, Inc.
2800K Dorr Ave.
Fairfax, VA 22031
Associated EquipmentAnalog: J.A. Michell Gyrodec turntable with Orbe platter and bearing; Ortofon TA110 tonearm and cable; Sumiko Blackbird, Denon DL-103R and Yamamoto Soundcraft YC-03S phono cartridges; Fosgate Signature phono stage.
Digital: Consonance Droplet 5.0 CD player, Korg DS-DAC-100 digital-to-analog converter.
Preamps: McCormack TLC-1, Yamamoto Soundcraft CA-04.
Amplifiers: InnerSound ESL stereo amp, McIntosh MC75 monoblocks, Yamamoto Soundcraft A-08 and A-09 stereo amps.
Speakers: Altec Lansing Valencia.
Cables: BPT IC-SL and MIT Shotgun S1 interconnects; BPT SC-9L and InnerSound ESL speaker cables; BPT C-9 and L-9CST, Yamamoto Soundcraft (came with amps) and Shunyata Research Zi-Tron Sigma power cords.
Power distribution: BPT 2.0 and CPT.