Angsty
Well-Known Member
The Opus3 high output will be fine with the PHO8.
Get your evening coffee for this explanation...
@HiFi Guy is describing the same thing calculated by the MC calculator on the Hagerman Labs site. With a low inductance of 6 mH, the low-output Opus3 acts more like a MC than a MM. With 100 ohm loading resistance, the calculated bandwidth is 2.7 kHz. That means no high frequencies at all. You ideally want a bandwidth at least 20 times that. With the high output Opus3, the inductance is still lowish at 55mH but loading at 47k ohms gives a bandwidth of 136.1 kHz, more than sufficient. That's why the Opus3 high-output works better. It's also a better match for the PHO8 MM gain setting.
As an aside, the calculator also predicts "optimum tuning" with capacitance and inductance. The "optimum" tuning would suggest about 24 pF of capacitance, which is about two feet of BJC LC-1 (ignoring that the tonearm wire also has some capacitance).
Yeah, cartridge matching is *still* one of the more fiddly parts of vinyl enjoyment. Calcs can help, but your ears will tell you what you like.
Get your evening coffee for this explanation...
@HiFi Guy is describing the same thing calculated by the MC calculator on the Hagerman Labs site. With a low inductance of 6 mH, the low-output Opus3 acts more like a MC than a MM. With 100 ohm loading resistance, the calculated bandwidth is 2.7 kHz. That means no high frequencies at all. You ideally want a bandwidth at least 20 times that. With the high output Opus3, the inductance is still lowish at 55mH but loading at 47k ohms gives a bandwidth of 136.1 kHz, more than sufficient. That's why the Opus3 high-output works better. It's also a better match for the PHO8 MM gain setting.
As an aside, the calculator also predicts "optimum tuning" with capacitance and inductance. The "optimum" tuning would suggest about 24 pF of capacitance, which is about two feet of BJC LC-1 (ignoring that the tonearm wire also has some capacitance).
Yeah, cartridge matching is *still* one of the more fiddly parts of vinyl enjoyment. Calcs can help, but your ears will tell you what you like.