Gain of line preamplifier

Anywhere from 0db(unity gain) typical to McCormack preamps.
Low-gain preamps such as Wyred4Sound will do about 6db,
Medium-gain such as Classe somewhere in 12dB
there are high gain preamps such as AudioResearch, Bryston will blast 20dB of gain
Passive preamp will vary the impedance while active preamp will keep it same. Variable output impedance is heavy disadvantage of any passive preamp even if you have substantially high input impedance of your amplifier.
If there's enough gain from source to poweramp, I'd choose either low-gain or unity-gain active preamp to achieve perfection and Nelson Pass would also agree with me. It will give you larger dynamic headroom and more pleasure at substantially larger volume range to dial REGARDLESSS of quality of passive preamp.
Manufacturers instead of gain would often provide you input sensitivity and max output voltage. 2 ways can be worked around this problem:
1. Contacting manufacturer about gain info
2. Use following formula to calculate gain:
a) Max_Voltage * 0.707 = RMS Voltage
b) 20Log(RMS Voltage/Input Voltage)
Personally, I would prefer purchasing preamps that have DETAILED specifications provided. Ones that aren't provided, would trigger my suspicion that they're not tested properly before going to the market.

Thank you,

How do you deal with analog? Most of the phono preamplifiers need more gain from the line level. And if you have a full function preamplifier most of the times you will have to much gain when you play CD. There are manufactores that compensate the gains of the two sections.

Vintage Accuphase E202 integrated have volume control that compensates line vs. phono.
I've used in the past Classe CP30(80's) that also didn't have any problems and volume had been compensated from both outputs.
On the other end, you should look for cartridge with sufficient output so that your line volume level will match to phono.
Separate phono boxes with adjustable gain is certainly best way! I'm not audiophile so I simply loop my phono preamp (Musical Fidelity X-LPS) that somewhat needs a-bit of higher boost vs. line signal through the Nakamichi tape deck that has its own recording level gain stage by simply engaging casset to pause-record mode. This way I get 'step up' stage to compensate with line stage. The electronics of the Nakamichi's recording level are simply superb!

10-24-14: Czarivey
Manufacturers instead of gain would often provide you input sensitivity and max output voltage. 2 ways can be worked around this problem:
1. Contacting manufacturer about gain info
2. Use following formula to calculate gain:
a) Max_Voltage * 0.707 = RMS Voltage
b) 20Log(RMS Voltage/Input Voltage)

I'm not sure this is correct. For preamps and line stages, when input sensitivity is specified it usually represents (with the volume control set at max) the input voltage required to drive the output to an indicated level, such as 1 volt, that is representative of a realistic operating condition. Not the input voltage required to drive the output to its specified maximum. The specified maximum is the maximum output voltage the preamp or line stage is capable of providing without clipping or gross distortion, and would usually and hopefully be a far higher voltage than would ever occur under normal operating conditions.

You may be thinking of power amps, where the specified input sensitivity usually represents the input voltage required to drive the amp to its rated maximum output power.

Also, I believe that maximum output voltage specs for preamps and line stages are usually expressed in rms terms, not peak, so the 0.707 factor would usually not be applicable.

Regards,
-- Al