LABORATORY TEST RESULTS
Newport Test Labs measured the frequency response of the Garrott Bros Optim FGS as 20Hz to 20kHz ±2.5dB, as shown in Graph 1. This is a truly excellent result, most particularly as regards the low frequencies, where most phono cartridges roll off quite rapidly (which is why many cartridge manufactures quote 30Hz to 20kHz or even 50Hz to 20kHz responses, rather than full-range.)
Channel separation was absolutely outstanding at low frequencies, better than 25dB. Again, this must be viewed in the light of most other phono cartridges, few of which manage more than 10dB. (However, it must be remembered that the low bass on LPs is always mono, so low-frequency separation is not overly important.) Channel separation at 1kHz was 28dB, which is 3dB better than specification. As expected, channel separation at high frequencies diminished dramatically, to 16dB at 10kHz, and to 12dB at 20kHz, but these figures are typical of most phono cartridges, including high-end models.
Distortion at 1kHz was a little higher than I expected, with a second harmonic component at –42dB (0.79%), a third harmonic at –55dB (0.17%), a fourth harmonic at –73dB (0.02%), a fifth harmonic at –76dB (0.01%) and a sixth at –85dB (0.005%) but since the second harmonic is euphonious, it would not be perceived as ‘distortion’ per se, but as added ‘lustre’ when playing music.
Square wave reproduction was excellent, exhibiting excellent low-and high-frequency frequency extension and a very fast rise-time. Newport Test Labs measured output voltage as 3.8mV at a velocity of 3.54cm/sec, exactly as per Garrott Bros’ own specification.
The Garrott Bros Optim FGS Phono Cartridge performed superbly on Newport Test Labs’ test bench and was particularly notable for the linearity and extension of its low-frequency response and the uniformity of its midrange response, which was within ±0.5dB. Steve Holding
Readers should note that the results mentioned in the report, tabulated in performance charts and/or displayed using graphs and/or photographs should be construed as applying only to the specific sample tested.