Sensitivity Ratings on Preamplifiers or Integrateds vs. Amplifiers

mesch OP Of course high sensitivity often drives one towards a passive pre. That was what drove my question.

Oh! how thoughtful of you.

Your 211ai "could" very well be just a poweramp with a passive and input selector switch at the front, many tube integrates are.
You could lower the gain some by increasing just one small resistor in the feedback loop of the poweramp section, this will give you tighter bass if you need it also, or make thing too controlled to what you want or are used to. Cost is a couple of cents and a few mins work. If you can get a ciruit diagram I can show you what resistor to change. Or maybe the Line Magnetic people will show you?

This is how the tubes are used from what I found and it does sound like a power with passive volume

12AX7 double triodes used for voltage amplification while the driver stage is realized with pair of 12AU7 double triodes for splitting Output stage consists of two pairs of EL34

I would also change the 12ax7’s (very high amplification tube btw) used a lot for phono stages, to my favorite input tube a 12AY7 (lower in amplification)

Cheers George

If there is any standard for sensitivity it might be 1.23V (+4dBu), but I remember few decades ago 0.3V (-10dBV) was common.  By using higher sensitivity they tried to save money - more gain in amp, but less gain stages in all sources.

http://www.harmoniccycle.com/hc/music-26-+4dBu-10dBV.htm

I'm not sure 1.23V (+4dBu) applies to power amps, since my Benchmark AHB2 offers three selectable input levels: 2V (8.2dBu), 4V (14.2dBu) and 9.8V (22dBu).  I use 9.8V, that they recommend.  At higher input level cable electrical noise pickup is lower in relation to signal while gain stages were moved from noisier environment (power amp) to cleaner one (pre-amp).   

My Benchmark DAC3 HGC has nominal 2V (8.2dBu) analog inputs sensitivity.  Benchmark usually knows what they're doing so perhaps the "standard" is 2V and not 1.23V.  Can anybody clarify?

Thanks, George. I wasn't aware of the 12AY7 tube. I believe there is another tube, having a 4 digit designation,  that can replace the 12AX7 for lower gain. Maybe the same tube with different designations?

I am currently not in the mood to get overly concerned about the gain issue specific to this amp to the point of modifying or even tube rolling it. I purchased it slightly used at a reasonable price to use as an educational tool to better understand the power requirements of my speakers, and to play with all tube amplification. It is serving me well for that. will likely move on from it. 

Currently using the Aric Audio pre into a SS amplifier. Should I purchase a all tube integrated I believe I would look into those having a active tube preamp stage. Otherwise a tube amplifier to rotate with a SS one using my preamp.

One thing about the LM 211ai, I believe it to be better suited to a vinyl system where the sensitivity could be an asset with lower gain cartridge and phonostage.  Either way, vinyl or digital it sounds very good with my Sterlings. I will have a better feel for how it compares with my preamp/amp combo one I reincorporate it into my system. Still getting familiar with the LM.