In illustration using a very low output cartridge vs a very high output cartridge connected to the Current Input vs Voltage Input on the P1
My Sonic Lab Ultra Eminent BC: 0.6Ω output 0.29mV
Voltage Input: At 0.29 mV, the Wizard determined the optimal gain level at +70 dB of gain. This setting has audible hiss coming from the speakers at 30% volume without any record playing. On careful listening, the gain level was sufficient. Optimal loading was determined to be 180Ω by the Wizard.
Current Input: At 0.6 Ω, the Wizard determined the optimal gain level to be I/V + 20 dB, but based on listening test I preferred a much lower setting of I/V + 5 dB.
According to Ohm's Law where I = V/R, Current = 0.29 / 0.6 = 483 Micro Amps, a very sufficient level of gain based on the low impedance of the cartridge.
- Are you using ohms law with voltage to compute the output current?
- I thought that the motors were generally current generating devices?
- So is the impedance of the phono stage a DC reading?
- And does and external loading become more like a V=I*R(total)