Educate me about gain and amp/preamp matching


I’ve been doing a bit of research on specifics on my second system. It comprises of a Quad ESL 2805 at 86db / 8ohm nominal driven by a Viva Linea preamp, which seems to have high gain (+12db I believe) at 150 ohm output impedance and an Atma-Sphere S-30 OTL amp at 30w/ch. The acoustically-treated room it’s setup up in is quite small - 9x20 to be exact, with the Quads about 5ft from the wall, and me only sitting about 5-6ft from the Quads, so pretty near field. Quads are ideal in this room since their dispersion is linear and minimizes room reflection. Even without the preamp gain added, an SPL calculator shows I can get up to 101db at listening position. 

Because of the size of the room and listening distance, everything sounds superb, but in many of the threads I read, people always state, including Ralph Karsten of Atma-Sphere, that the Quads need more than 50w of power to perform their best.


Does the fact that I am pairing the Atma-Sphere with a higher gain preamp help this situation? I’m not hearing any clipping or noise due to driving a stronger signal into the amp. And even if the signal coming into the amp has more gain to begin with, at I still limited to small headroom due to the 30w the amp puts out?


Happy to provide any specific information needed to answer this. Thanks for helping me understand the science behind it because aurally it sounds great.


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Showing 1 response by gs5556

Look at it this way: assume two cars with the same engine are accelerated to 50 mph. The first car requires the gas pedal depressed 1-inch and the second car requires the pedal depressed 1.5-inch. Both have a different gain but both have the same maximum hp and both are putting out the same power. The only differences are the second car may run out of pedal before max power is reached;  the first car will still have pedal travel after max power is reached but nothing changes in that extra travel.