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Regarding measurements, I use a mixture of nearfield, in-room, and quasi-anechoic FFT techniques (using the MLSSA system from DRA Labs described elsewhere in this issue) to investigate objective factors that might explain the sound heard. The speakers' impedance phase and amplitude were measured using the magazine's Audio Precision System One.

The AE2's impedance curve (fig.1) reveals the port tuning to lie at 42Hz. The use of two 8 ohm woofers means that the minimum impedance drops to 4 ohms in the upper-bass/lower-midrange, though it remains above 6 ohms…

Description: Two-way, reflex-loaded, stand-mounted loudspeaker. Drive-units: 1" (25mm) metal-dome tweeter, two 4.5" (110mm) metal-cone woofers. Crossover frequency: 3kHz. Crossover slopes: 4th-order, 24dB/octave. Frequency response: 65Hz–18kHz ±2.5dB, 50Hz–22kHz ±4dB. Sensitivity: 91dB/W/m (2.83V). Nominal impedance: 8 ohms (5.5 ohms minimum at 50Hz and 250Hz, 16 ohms maximum at 27Hz). Harmonic distortion (no frequency specified): less than 0.05% of second and third harmonic at 90dB at 1m; less than 0.1% of second and third harmonic at 100dB at 1m. Power…

Amplifier designers have frequently looked for ways to marry the advantages of tubes to those of solid-state devices. Hybrid designs of various stripes have appeared over the years, most of them using tube input stages with transistor output stages, eliminating the major weaknesses of tube amplifiers: eg, they run hot, are unreliable in that tubes have a finite life, are more expensive than a similarly powerful solid-state design, and have power-hungry output tubes and output transformers.

Counterpoint Electronics has long been a…

Comparisons
I compared the Counterpoint with the McCormack DNA-0.5, which did the better in the comparison. The $1295 McCormack sounded sweeter overall on the SC-IVs—though I did note an occasional brightness in the low treble which hadn't been apparent before, and of which the Counterpoint was free. Both amplifiers performed well on the Holly Cole Trio's Don't Smoke in Bed (Manhattan B21Z-81198), but…

Loudspeakers used to audition the Counterpoint were Mirage M-7sis, Dunlavy SC-IVs, and Energy Veritas v2.8s. Amplifiers on hand for comparisons were the Krell KSA-300S and McCormack DNA-0.5. Program source was a Krell KPS-20i CD player used as a transport, feeding a Mark Levinson No.35 D/A converter through a Kimber AGDL digital coaxial cable.

Unbalanced TARA Labs Master RSC connected the Levinson converter to a Rowland Consummate preamp. Preamp-to-power-amp interconnects were alternately Monster M1500s and Cardas Hexlink Five Series, and…

A full set of measurements of the Counterpoint NPS-400A was made in its unbalanced mode, with selected measurements repeated for the balanced configuration. Unless otherwise noted, the results presented are for the unbalanced configuration.

Following the 1/3-power, one-hour preconditioning test, the NPS-400A's heatsinks were very warm, but not unusually so. The NPS-400A is non-inverting in the unbalanced mode; in the balanced, pin 2 is configured as the positive leg, pin 3 the negative.

The NPS-400A's input impedance measured 96.5k ohms at 1kHz (…

Description: Hybrid amplifier design with class-AB output stage. Rated power: 200Wpc into 8 ohms (23dBW), 400Wpc into 4 ohms (23dBW), 700Wpc into 2 ohms (22.4dBW). Dynamic headroom: 3dB. Rated full-power bandwidth: 20Hz–20kHz. Input impedance: 100k ohms. Input sensitivity: 92mV. Rated THD: 0.5%. S/N ratio: 90dB.
Dimensions: 19" W by 7.4" H by 18" D. Weight: 65lb.
Serial number of unit reviewed: 1NPS432 first, then 1NPS491.
Price: $4395 (1995); no longer available (2021). Approximate number of dealers: 70.
Manufacturer: Counterpoint Electronic…

Preview, from July 1968 (Vol.2 No.6): Overall sound extremely good, but phono sounds slightly lacking in deep bass, despite impeccable measurements. Scratch filter judged very highly effective, but tone controls felt to be less than ideal because of excessively coarse action and marked tendency to affect midrange output. Spring-return Tape Monitor switch probably will not appeal to serious tapesters. This preamp is…

To try and settle the matter once and for all, we spent a couple of days trying to devise an equalizing network which could be connected to a tape machine's outputs and would…

Dynaco offered us the schematic for an input equalizer like the one we tried to put together, except that this one works. We accept the offer with many thanks.

Further Thoughts, from June 1970 (Vol.2 No.10)
In our report on the Dyna PAT-4…