Manufacturer's Comment
The Stereophile's subjective observations point up the importance of listening critically to any proposed amplifier-speaker combination because there may possibly be subtle differences which are significant to the perfectionist. However, subjective impressions are influenced by listening environment and other variables, and rarely reflect reproducible concurrence by different listeners. We have expended considerable effort in trying to formulate test procedures which equate general listening impressions with measurements, with some success. Conventional specifications are important (there has never been a good amplifier which did not measure well by these standards), but there are other criteria whose results are quite difficult to measure. They help to separate the superior from the "almosts," and these criteria may affect subjective impressions. We do not have the reservations about using the Stereo 120 with the KLH Model Nine that The Stereophile has (and we note the observation that this was at least partly dependent on source limitations), and can only suggest that anyone contemplating this expenditure make such comparisons for himself, but we have always contended that the Stereo 70 is an ideal amplifier for that speaker. Any good transistor amplifier should include protective circuitry to guard against the likelihood of trouble with unconventional loads. While tube amplifiers are much more tolerant of abuse than are transistor amplifiers, even they are not immune to damage. The Stereo 120 could have been released much earlier if we had not considered full protection to be important. Its protective circuitry will reduce the power output or shut down the amplifier if it encounters a severe overload, with instant restoration when the overload is removed. Although The Stereophile has found this protection fully adequate, the surest safeguard is avoidance of abuse. Undue activation of a safety device is like testing a parachute; it works fine almost 100% of the time, but most of us prefer not to put it to the test.—David Hafler
Reviewer's Addendum
For those who can stretch their finances that far, a speaker setup comprised of two complete KLH Nines (four panels, with each pair coupled together) will provide the most nearly-perfect reproduction of sound that it is possible to get from commercially available components, regardless of price. With each pair connected in parallel, 8-ohm impedance would provide a nominally correct match to the Stereo 120, and would allow full utilization of its power output capabilities.—J. Gordon Holt
The Stereophile's subjective observations point up the importance of listening critically to any proposed amplifier-speaker combination because there may possibly be subtle differences which are significant to the perfectionist. However, subjective impressions are influenced by listening environment and other variables, and rarely reflect reproducible concurrence by different listeners. We have expended considerable effort in trying to formulate test procedures which equate general listening impressions with measurements, with some success. Conventional specifications are important (there has never been a good amplifier which did not measure well by these standards), but there are other criteria whose results are quite difficult to measure. They help to separate the superior from the "almosts," and these criteria may affect subjective impressions. We do not have the reservations about using the Stereo 120 with the KLH Model Nine that The Stereophile has (and we note the observation that this was at least partly dependent on source limitations), and can only suggest that anyone contemplating this expenditure make such comparisons for himself, but we have always contended that the Stereo 70 is an ideal amplifier for that speaker. Any good transistor amplifier should include protective circuitry to guard against the likelihood of trouble with unconventional loads. While tube amplifiers are much more tolerant of abuse than are transistor amplifiers, even they are not immune to damage. The Stereo 120 could have been released much earlier if we had not considered full protection to be important. Its protective circuitry will reduce the power output or shut down the amplifier if it encounters a severe overload, with instant restoration when the overload is removed. Although The Stereophile has found this protection fully adequate, the surest safeguard is avoidance of abuse. Undue activation of a safety device is like testing a parachute; it works fine almost 100% of the time, but most of us prefer not to put it to the test.—David Hafler
For those who can stretch their finances that far, a speaker setup comprised of two complete KLH Nines (four panels, with each pair coupled together) will provide the most nearly-perfect reproduction of sound that it is possible to get from commercially available components, regardless of price. With each pair connected in parallel, 8-ohm impedance would provide a nominally correct match to the Stereo 120, and would allow full utilization of its power output capabilities.—J. Gordon Holt
