lewm always argument something with " wrong " questions as this to myjos:
" You have heard the JC1 and the Hyperion driving the same pair of Sound Lab speakers in the same room with the same upstream gear? "
First mijos was not talking of the old JC1 but today JC1+ that's way different and maybe he never read the MF review along the measurements on the Hyperion amps where we can read:
by MF:
"
No doubt the single tube in the Hyperion's signal path subtly greased the musical proceedings with a smooth yet transparent overlay of richness. Having become acclimated in recent years years to the sound of the darTZeel NHB-458, which is less generous in the upper bass and lower midrange (detractors of solid-state designs might describe its sound as "thin") and is faster in the transient realm (detractors might say "overly and unrealistically sharply drawn"), the gross distinctions between these two great performers were easily audible..........
But even while the contours of the new sound were still easily definable and the differences between the two amplifiers were still clear...."
and JA measurements comments:
"
While the Hyperion's input impedance is specified as a moderately high 47k ohms, my measurements indicated a lower value at low and middle frequencies: just over 21k ohms for both the balanced and unbalanced inputs. This is still high enough not to be an issue, but at 20kHz the impedance dropped to just 3k ohms, which will be marginal with some preamplifiers, rolling off the top octave. Fortunately, this shouldn't have affected Michael Fremer's listening, given his associated equipment: His Ypsilon PST-100 preamplifier has a low output impedance, and his darTZeel preamplifier has a fairly uniform, if high, output impedance across the audioband.
Despite the Hyperion's large number of output devices, its output impedance was relatively high for a solid-state design, at 0.35 ohm. As a result, the modification of the amplifier's frequency response with our standard simulated loudspeaker reached ±0.25dB (fig.1, gray trace). Of more concern is the ultrasonic peak in the Hyperion's response, centered between 40 and 50kHz and reaching 2dB in height. The peak gave rise to a single damped cycle of oscillation with a 10kHz squarewave (fig.2) and was not affected by the load impedance, which suggests that it occurs before the output stage, perhaps at the input transformer.
However, as figs. 3–5 reveal, at our usual definition of clipping, at which the THD+noise reaches 1%, the Hyperion delivered 239W into 8 ohms (23.8dBW), 400W into 4 ohms (23dBW), and 315W into 2 ohms (19dBW). It did meet its specified power when I relaxed the definition of clipping to between 1.4% and 2% THD+N, but these are disappointing results.
Of more concern in these graphs is the Hyperion's linear increase in distortion with increasing power output above a few hundred milliwatts. While the THD+N percentage remains acceptably low below 10W or so, above that power, and especially at low frequencies, it reaches levels that will be audible with continuous pure tones...
When MF comments on "the immediately obvious added harmonic and textural richness," that it is what I would expect from this distortion signature. In addition, the Hyperion's intermodulation distortion was not as low as I would have liked.
Given that, it is not an amplifier that I would recommend, especially given its price. While I have found that power amplifiers tend to sound different from one another, I feel they should be engineered to be as close to neutrally balanced as possible, and not designed to produce a "tailored" sound, as the Hyperion seems to be.—
Obviously dover made the same that lewm in this specific matter. As I said, knowledge levels is the " name of the game ".
R.
