My reference system consists of an Audio Research SP20 preamp, and a 30Wpc Berning ZH-230 amplifier, connected by High Fidelity CT-1 interconnect cables. Total cost: $19,160. To be fair, the SP20 includes a fine phono preamp; still, the cost is over twice that of the EHF-100 Mk2. And that doesn’t include the price of an extra shelf needed for the amp/preamp configuration. I normally use a JL Audio f110 subwoofer, but to make things comparable to the subwooferless EHF-100 Mk2, I left the sub turned off for the comparison.
Through my reference system, Frottole had a bit more precise soundstage. Vocal textures were more solid as well; I could understand the text better. Well, not really. I don’t speak Italian, but the pronunciation was a smidgen more distinct. Microdynamics, a strong point of the Berning amplifier, were just as well reproduced as through the EHF-100 Mk2.
Even sans subwoofer, the track “Folia Rodrigo Martinez” had noticeably deeper and more impactful bass from my reference system. Maybe that stemmed from the fact that the Berning amplifier uses an output transformerless circuit. This very information-dense recording packs a lot of detail into the soundstage, with dynamics varying continuously as the performers traverse the piece.
“Just a Little Lovin’” also had more bass punch and depth. Lynne’s vocals were equally expressive and resolved, and instrumental detail was also noteworthy. The bass provided a better underpinning for this music.
Rhapsody in Blue was reproduced by my reference system with excellent detail, but seemed to be lacking an element of excitement that made it come across as more mechanical. I hate it when a reviewer says something like that; there’s certainly not an excitement track on the recording, and the dynamics which I normally credit with providing more excitement were reproduced just as well. I suspect the EHF-100 Mk2 may have had better timing—but that’s only a theory.
Through my reference system, the choral group in “Salvator Mundi” sounded slightly more focused and projected more power. Solo parts were a smidgen more distinct.
If I say that overall I preferred the sound of my reference system, let me reiterate that it costs over twice as much and is rated at less than half the power of the EHF-100 Mk2. I’ve spent years putting the system together to get a sound that’s just to my taste. While my Berning amplifier drives my very sensitive horn speakers quite well, it might not be capable of driving lower sensitivity speakers nearly as well.
The Rogers EHF-100 Mk2 integrated amplifier was a harmonically rich, dynamically powerful amplifier that was satisfying to listen to over long periods. With a smoothly extended high end, a detailed, realistic midrange, and tight bass, it should have enough power to drive a wide variety of speakers. Its automated bias setting eliminates one of the chief objections to tube amplifiers, assuring the amplifier will deliver peak performance for the life of the tubes with no effort from the owner.
The EHF-100 Mk2’s unmatched lifetime warranty tells us that Rogers doesn’t expect the amplifier will ever cause the original owner or second owner any problems, so except for normal tube wear, you shouldn’t have any trouble with the amplifier, something I can’t say about any other amp I’ve used. And the tubes are current production models, so replacements should be easily obtainable at moderate cost—and easy to access when you do need to replace them. (A recommended source for replacement tubes is listed in the user manual, and the 12AX7s and KT88s are often available at local guitar stores.) The optional power cord and remote control were solidly constructed and contributed to the amplifier’s performance.
If you’ve been tempted by tube amplifiers but aren’t sure you want the hassles that come with many of them, the Rogers EHF-100 Mk2 is about as easy to maintain as a tube amplifier can be, and offers the typical sonic advantages a tube amp provides with the best warranty in the industry. Highly recommended.
SPECS & PRICING
Tube complement: 2x EF86, 2x 12AX7, 4x KT88
Power: 65 watts RMS per channel/0.1dB from 20Hz to 20kHz with less than 0.1% THD
Inputs: Four unbalanced
Output: 4 ohms
Dimensions: 17" x 10" x 14"
Weight: 50 lbs.
Price: $8000 (Rogers High Fidelity Quiet Cable, $1900 for a 10' length; Rogers High Fidelity Upgraded Remote Control, $300)
Speakers: Affirm Audio Lumination speakers, JL Audio Fathom f110 subwoofer
Headphones: Audeze LCD-X, NAD VISO HP50, AKG K701, AKG K712
Amplifiers: Berning ZH-230 stereo amplifier, Linear Tube Audio microZOTL 2.0 headphone amp, JDS Labs O2 headphone amplifier, LH Labs Geek Out V2 headphone amp/DAC, Meridian Explorer2 headphone amp/DAC
Preamplifier: Audio Research SP20 preamp
Analog sources: Linn LP-12 turntable on a custom isolation base, Graham 2.2 ’arm, van den Hul Platinum Frog mc cartridge, Audio Technica AT120EB mm cartridge; Sony XDR-F1HD tuner (Radio X modified)
Digital sources: Sony SCD-XA5400ES SACD player; Hewlett Packard Envy laptop computer running 64-bit Windows 7 Home Premium and Roon server software; SOtM sMS-1000SQ server and sPS-1000 power supply; PS Audio DirectStream DAC; QNAP TS-251 Network Attached Storage drive
Interconnects: Crystal Cable Piccolo unbalanced interconnects, Clarity Cables Organic interconnects, Audience Au24 e balanced interconnects, Purist Audio Design Venustas unbalanced interconnects, Wireworld Cable Gold Eclipse 7 balanced interconnects, CablePro Freedom unbalanced interconnects
Speaker cables: Clarity Cables Organic loudspeaker cables
Power cords: Purist Audio Design Venustas, Blue Marble Audio Blue Lightning, Clarity Cables Vortex, Audience powerChord e, Au24 SE LP powerChord
Digital cables: Wireworld Platinum Starlight 7 USB cable, AudioQuest Coffee and Diamond USB cables, Paul Pang TZ YUN Red II USB Cable, Audience Au24 SE USB cable, Au24 SE SPDIF cable
Power conditioner: Audience aR6-T