From: alexander.dyszewski@chello.at   
      
   flipper schrieb:   
   >> where is the point in making the input sensitivity of a modern amplifier   
   >> as low as 250mv ?   
   >   
   > I don't know that I'd pick 250mV but the problem is things are not as   
   > precise as you're making out.   
   >   
   >> Lets assume the amplifier needs 0,775Vrms (=0dBu) for full output and   
   >> most digital sources tend to produce about 2Vrms   
   >   
   > I think you're already in trouble making that assumption as 1Vrms,   
   > which you mention below, is also rather common.   
   >   
   > Is the goal to work with something specific you already have or cover   
   > the range of what's available? If the latter then you don't have the   
   > luxury of 'most sources' even if you're right about what's common.   
      
   I want to cover a reasonable range of possible sources like "normal"   
   japanese hifi components.   
      
   >> leaving a 8dB margin   
   >> for quieter recordings.   
   >   
   > Here you have a *wide* range, depending on what you listen to.   
   >   
   > First, the '2Vrms' (1Vrms) is digital speak for full scale output, not   
   > nominal. There is nothing, not so much as one pico volt, more than FS   
   > and that means someone trying to do 'hi quality' is not going to   
   > approach full scale because of clipping. If I remember correctly,   
   > peaks (true peak meter) 6dB under FS is the recommended 'safe' setting   
   > and if it's a 1Vfso device that's already down to 500mV peaks.   
   >   
   > 'Modern' rock will compress the bejesus out of things to compete in   
   > the volume wars, so nominal will not be low. Classical, however, to   
   > keep dynamic range, will have nominal depressed along with staying   
   > away from full scale. Early rock recordings, from back in the days   
   > when they thought CD was supposed to be 'high quality', will be closer   
   > to the 'classical' level because it isn't compressed flat as a   
   > screaming cow pattie up against FS.   
      
   I disregarded classical music, because most of my cds are metal, rock   
   and electronic. But you do have a point there, some cds do have quite a   
   lot of dynamic range.   
      
   > On top of that you have listener preference and you seem to be   
   > assuming it's to never drive into clipping regardless of what nominal   
   > volume level that dictates but some (many?) will turn it up till it   
   > hurts, which is clipping, so 'max power' is not necessarily your   
   > 'peak' point. This, btw, is especially true of tube gear because they   
   > (usually) clip more gracefully than SS.   
   >   
   > Then, silly as it may seem, there's the volume knob itself and people   
   > don't like it pegged on max because that feels like it's 'run out of   
   > volume', never mind whether it's usable.   
   >   
   >   
   >> I found a Marantz Fmtuner with 1Vrms Output and   
   >> i think other tuners will bei similar. This will give only about 2dB   
   >> margin, but since most fm broadcasts are modulated noise anyway there   
   >> should be no problem in achieving full volume.   
   >   
   > I have no idea what your reasoning there is. 'Noise' isn't going to   
   > help it reach max power.   
      
   My idea was that since fm-broadcasts tend to be extremely compressed and   
   enchanced for kitchen radios there is no need for additional gain in the   
   preamplifier.   
      
   >> High quality reel-reel   
   >> tapedecks will have balanced XLR connectors giving +4dBu which equals to   
   >> 1,2Vrms. So again no reason for low input sensitivity. Riaastages might   
   >> be different, but i think that a high quality preamplifier should be   
   >> able to deliver 0dBu even with strangely mastered records.   
   >   
   > Consumer line level is 316mVrms nominal.   
   >   
   >   
   >> Can anybody here think of any (high quality) source that will actually   
   >> need such high sensivity ?   
      
   Thank you for the very informative post.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)