Mr Spock
demokratischer - sektor
- Μηνύματα
- 18.455
- Reaction score
- 50.601
The instruction manual avers that the amplifier should not be considered as either a theoretically ideal voltage source or an ideal current source, both of which, in addition to many flaws, have good qualities. To paraphrase the manual's "Franglish," a perfect voltage source has zero output impedance and in practical terms requires 100% negative and global feedback, which produces temporal (phase) distortion. An ideal current source has infinite source impedance, which is good for controlling a speaker's back EMF, but produces poorer measured performance and sound quality that is overly speaker-dependent. The company claims that the CP2C circuit produces an amplifier-to-speaker connection equivalent to the matched impedance links—the 50 ohm "transmission line" Zeel connection—that darTZeel uses between their NHB-18S preamp and its amplifiers.
The 468 is rated as outputting 475W RMS (550W peak) into 8 ohms, 625W (700W peak) into 4 ohms, and 222W RMS (300W peak) into 2 ohms. That's bound to raise some eyebrows, especially considering the massive power supply, with 750 joules of available energy. Power measurements for its predecessor, the NHB-458, are 530W into 8 ohms, 800W into 4 ohms, and 1025W into 2 ohms. Note that both amps use the same massive power supply, featuring one of the biggest power transformers I've encountered in an audio product, which floats on a suspended platform that's tuned to absorb frequencies between 40Hz and 70Hz.
Conclusion
The darTZeel owners I've met seem to be a happy, enthusiastic group, satisfied with their purchases and with the sound produced by whichever darTZeel products they have. Count me among them. The new NHB-468 has made me even happier. This amp does what the NHB-458 does—just better. It's got power to spare and sounds as if it's just loafing, even on the most demanding material.
I haven't seen the measurements and won't until I see the final proofs of the finished article, but I assume the distortion measurements will be good but bettered by some. I believe Delétraz is capable of reducing distortion to as low as is measurable, but he's going for something beyond measured perfection, and I think he's achieved his goal in terms of a unified, holistic, natural sonic pictur
frequency response at 2.83V into: 16 ohms (gray), 8 ohms (blue), 4 ohms (magenta), 2 ohms (red) (0.5dB/vertical div.)
distortion (%) vs 1kHz continuous output power into 8 ohms.
Description: Solid-state monoblock power amplifier. Inputs: one unbalanced (RCA); one unbalanced Zeel (BNC); one balanced (XLR). Output power: 475W (26.8dBW, 550W peak) into 8 ohms, 625W (25.0dBW, 700W peak) into 4 ohms, 222W into 2 ohms (17.45dBW, 300W peak)—"design limited because CP2C power is delivered differently into speakers than when statically measured." Voltage gain (user selectable): 26 or 32dB into 8 ohms. Input impedance: >30k ohms, (RCA); 50 ohms, ±1 ohm (Zeel); 10k ohms per phase (XLR). Output impedance: <0.28 ohm, 20Hz–20kHz (into 8 ohms). Frequency response: 0.7Hz–700kHz, +0/–3dB; 20Hz–20kHz, +0/–0.2dB. THD: <1%, 7Hz–77kHz. Signal/noise: >115dB, A-weighted, ref. nominal power. Risetime: 0.9µs. Slew rate: >200V/µs, peak-peak. Temporal distortion: "none, at any level and load as specified above." Power consumption: 2W in standby, 40W at idle, 2kW at maximum output power.
Dimensions: 18" (460mm) H by 11" (277mm) W by 20" (511mm) D. Weight: 154lb (70kg).
Serial numbers of units reviewed: TZ-UE1468.010L/R.
darTZeel NHB-468 monoblock power amplifier
What's the point of reviewing a pair of monoblock amplifiers that costs more than most people spend on two or even several cars and far more than most audiophiles spend on an entire music system? That's a good question. Another is: Why should I write this review when, just seven years ago, I...
