Like many Conrad-Johnson designs, the MF2500's higher performance goals have been attained…
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Rumor had it that if the MF2500 amplifier had gotten any better in development, Conrad-Johnson would have had to include it in their "Premier" series. However, C-J's intention was to hold to the lower price of their established MF series, and so they have. Rated at 240Wpc and retailing for $3495, the '2500 is the core model of Conrad-Johnson's current range of "MF" power amplifiers. Its companion MF2250 offers 120Wpc, while the MF5600 delivers 120Wx5 for multichannel home-theater applications.
Sidebar 1: Specifications
Description: Solid-state stereo power amplifier. Maximum output power: 240Wpc into 8 ohms (23.7dBW), 20Hz–20kHz, at less than 1% IMD or THD. Frequency response: 20Hz–20kHz, +0/–0.1dB. Hum and noise: 100dB below rated output. Input impedance: 100k ohms.
Dimensions: 19" W by 6.75" H by 16" D. Weight: 55 lbs.
Serial number of unit reviewed: Not noted.
Price: $3495 (1999); no longer available (2007). Approximate number of dealers: 80. Warranty: 3 years.
Manufacturer: Conrad-Johnson Design, 2733 Merrilee Drive, Fairfax, VA 22031. Tel: (703) 698-8581. Fax…
Sidebar 2: Associated Equipment
Analog source: Linn LP12/Naim ARO/Koetsu Rosewood II/Lingo.
Digital sources: Krell KPS-25s, Marantz CD-7, Naim CDS11 CD players.
Preamplification: Krell KPS-25s; Conrad-Johnson Premier Fifteen, ART, and PFR.
Power amplifiers: Krell FPB 200 and FPB 650M; Cary 300SE LX20; Naim NAP250; Conrad-Johnson MF2300A, Premier Eleven A, and CAV50.
Loudspeakers: Wilson WITT Mk.II, B&W Nautilus 803, Sonus Faber Signum, Harbeth HL7ES, Quad ESL-63.
Cables: Transparent Music Wave Plus, van den Hul, Siltech.—Martin Colloms
Sidebar 3: Measurements
While the Conrad-Johnson MF2500 will drive 4 ohm loads with music, the output specification is given as 240Wpc (23.8dB/W) for 20Hz–20kHz, at less than 1% of IM or harmonic distortion, both channels driven into 8 ohms. Don't be concerned at that high-looking figure of 1% distortion—in practice, the figures are much less than this. What this figure reflects is C-J's disdain of slavish conformance to the artificially low distortion figures adopted by many companies without regard to sound quality.
Tested with the UK's 242V, 50Hz power supply, the MF2500…
McIntosh: "...for the love of music..."
by Ken Kessler. McIntosh Laboratory, Inc., 2006. $150.00. Hardcover, 12" by 12" by 1.25", 315 pp. ISBN 0-9787236-0-0.
Available from McIntosh dealers and McIntosh Laboratory, Inc., 2 Chambers Street, Binghamton, NY 13903. Tel: (800) 538-6576.
by Ken Kessler. McIntosh Laboratory, Inc., 2006. $150.00. Hardcover, 12" by 12" by 1.25", 315 pp. ISBN 0-9787236-0-0.
Available from McIntosh dealers and McIntosh Laboratory, Inc., 2 Chambers Street, Binghamton, NY 13903. Tel: (800) 538-6576.
When I reviewed Ken Kessler's book Quad: The Closest Approach, in Stereophile's February 2004 issue, I offered the opinion that the list of companies it might make sense to write an entire book about would be short: "Had I to make a list, it would begin with: Quad, Nakamichi, ReVox-Studer, AR, KLH,…
It's not often that you get a chance to have extensive discussions with the horse's mouth, but we recently had that opportunity. Since July of this year there has been extensive discussion in the audio community, particularly the high-end segment, of Larry Greenhill's article on speaker cable listening tests in the August, 1983 issue of Stereo Review (footnote 1). From recent talks with author Greenhill we've learned that the most interesting story was not in Stereo Review; instead it can be found in the varying reactions from different quarters, and what they say about the high-end industry…
"The striking outcome is that the panel accurately heard and named speaker cables in 5 out of 6 comparisons. The listeners felt pleased after this listening test battery: they had heard real differences! After the 50 hours of testing, scoring, comparing, and just plain listening, they were exhausted but felt accomplished. Both Monster Cable and 24-gauge wire could be heard reliably under double-blind conditions." (footnote 6)
Big difference, wouldn't you say? Yet Greenhill's original actually allows for two totally different interpretations of the data. One measure of the reliability of…
I hate all those automobile reviews that go on and on about a car's design aesthetics. C'mon, I can see what it looks like, even if only in the pictures. Just tell me things I can't appreciate without a run on the Autobahn.
Now, just take a look at the Bow Wazoo. Trust your eyes. Trust the fact that it won the 1998 Golden Note Award for "Most Aesthetic Audio Design." Trust the guys from The Wiz, who delivered my new TV and, seeing the amp on the rack, said, "Man, that's cool. What is it?"
Okay. Now we can put form aside and address substance. Bow calls the Wazoo a "single-chassis…
The Wazoo's low end had a distinct character that complemented most speakers. It seemed ever so slightly warm in the upper bass, ever so slightly lean in the lower bass. The effect of this was positive on every speaker I tried.
The first setup was with the Gershman GAP-20x speakers, the Wazoo behind them and the sources running through 10m of Cardas Cross interconnect. Compared with other, bigger amps, the Wazoo was their equal at all reasonable levels until this 50Wpc overachiever ran out of steam—and that was at levels sufficient to raise my neighbors and the dead (only the former…
Sidebar 1: Specifications
Description: Solid-state integrated amplifier. Inputs: 5 pairs line-level, 1 pair single-ended and balanced. Outputs: 1 pair preamp/monitor. Binding posts: 4 multiway WBTs. Continuous power: 50Wpc into 8 ohms (17dBW), 90Wpc into 4 ohms (16.5dBW). Frequency response: 2Hz–200kHz (–3dB). S/N ratio: 110dB, A-weighted, ref. full power. Channel balance within 0.3dB. Input sensitivity: 500mV. Input impedance: 1.2k ohms. THD: <0.5%. Power consumption: 70W idle, 500W max.
Dimensions: 17.1" (434mm) W by 5.5" (140mm) H by 16" (407mm) D. Weight: 44 lbs (20kg).
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