Unity gain means that output voltage equals input voltage, which corresponds to a gain of 1 when expressed as a ratio, or to zero when expressed in db. Mike must have been referring to the gain of some stage within the amp, rather than to the gain of the amp’s entire signal path. Also, btw, the gain of an integrated amplifier (or preamp) is usually specified based on the volume control being set at max.
The Six Moons review of the amp stated that it provides "26dB of voltage gain in just the line stage followed by another x 20 amplification factor in the power stage." "x20" is also a gain of 26 db, so the overall gain is indicated to be 52 db, which is very high. (26 db of power amp gain is fairly typical, but 26 db of line stage gain is very high although not unheard of). I suspect, btw, that the model they reviewed was an early version which (like the one Nonoise has) did not have a gain switch, and the 52 db overall gain corresponds to what is provided by recent models when the gain switch is set to its high sensitivity position.
Also, those numbers seem consistent with reports from several users of having to set the volume control at very low settings.
The sensitivity specs for the amp are not consistent with such high gain, though. It can be calculated from the specified 215 watt/8 ohm power capability of the amp and the specified high and low sensitivities of 2.25 and 3.6 volts (which differ by 4 db, btw, not by 6 db) that those numbers correspond to gains of only 25 db and 21 db, respectively, which would be **very** low for the overall gain of an integrated amp. Given the Six Moons review and the several user reports I referred to, it seems clear that either those numbers are very inaccurate or else they are defined very differently than how sensitivity specs are usually defined, which in turn is the input voltage required to drive an amp to full power when the volume control (if present) is set at max.
Personally, if I were to consider pairing that amp with 101 db speakers I would count on having to put a Rothwell attenuator between my source components and the amp, especially if any of the sources are digitally-based (as opposed to vinyl). And I would also have some concern that hiss or other noise generated either within the amp or as a result of ground loop issues between the amp and the source components might be boosted by the high gain to the point that it becomes excessive.
Regards,
-- Al
The Six Moons review of the amp stated that it provides "26dB of voltage gain in just the line stage followed by another x 20 amplification factor in the power stage." "x20" is also a gain of 26 db, so the overall gain is indicated to be 52 db, which is very high. (26 db of power amp gain is fairly typical, but 26 db of line stage gain is very high although not unheard of). I suspect, btw, that the model they reviewed was an early version which (like the one Nonoise has) did not have a gain switch, and the 52 db overall gain corresponds to what is provided by recent models when the gain switch is set to its high sensitivity position.
Also, those numbers seem consistent with reports from several users of having to set the volume control at very low settings.
The sensitivity specs for the amp are not consistent with such high gain, though. It can be calculated from the specified 215 watt/8 ohm power capability of the amp and the specified high and low sensitivities of 2.25 and 3.6 volts (which differ by 4 db, btw, not by 6 db) that those numbers correspond to gains of only 25 db and 21 db, respectively, which would be **very** low for the overall gain of an integrated amp. Given the Six Moons review and the several user reports I referred to, it seems clear that either those numbers are very inaccurate or else they are defined very differently than how sensitivity specs are usually defined, which in turn is the input voltage required to drive an amp to full power when the volume control (if present) is set at max.
Personally, if I were to consider pairing that amp with 101 db speakers I would count on having to put a Rothwell attenuator between my source components and the amp, especially if any of the sources are digitally-based (as opposed to vinyl). And I would also have some concern that hiss or other noise generated either within the amp or as a result of ground loop issues between the amp and the source components might be boosted by the high gain to the point that it becomes excessive.
Regards,
-- Al