4yanx, I think the table you were given is an acceptable minimum for those who strive for lowest noise in the phono stage. I myself would want even more gain if the noise floor of the phono gain circuit was up to it. Matching gain, impedance and noise is very important early in the signal path. Small imperfections in the source end are amplified and add up to big imperfections in sound. Please correct me if I am wrong but I reckon it make better engineering sense to use a low noise high gain phono stage designed to add little noise of its own and that of the MC cartridge (thermal noise) than relying on a high gain line stage which would amplify the noise of a low gain phono stage. Thus I prefer less gain (<20db) in the line stage of a preamp. With (SA)CD players and tuners easily putting out 2+ volts, more than 8 db in the line stage just isn't necessary to drive most amps. Perhaps an adjustable gain setting in the line stage is a sensible option.
Will our MC for the festivities gain the stage?
Those of us who own preamps with phono stages are familiar with the phrase, “will handle MM cartridges and most MC cartridges”. The word “most” becomes critical when considering many of the low-output pickups available. My Kora Eclipse, for example, has separate MM and MC inputs and the MC stage is rated at .4mV/100ohm with a gain of 55dB. At what point is that 55dB gain insufficient to handle EFFICIENTLY a very low-output pickup? .5mV, .6mV? I know that it does depend upon actual output of the pickup and there are no hard and fast rules. I was given the following general guidelines some time ago which I post below. Does this seem like a good “rule of thumb” or is someone prepared to give it the finger, instead? Thanks.
0.2-0.5 mV needs 63dB gain
0.6-1.9 mV needs 50dB gain
2.0-5.0 mV needs 37dB gain
0.2-0.5 mV needs 63dB gain
0.6-1.9 mV needs 50dB gain
2.0-5.0 mV needs 37dB gain