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Re: 30W per channel (300B) to drive 81db LS3/5A?

69.208.89.160

Posted by ARC on January 7, 2007 at 08:16:04

In Reply to: 30W per channel (300B) to drive 81db LS3/5A? posted by sktung on January 7, 2007 at 05:27:01:

Personally, I wouldn't drive 81/db efficient speakers with anything less than something like an Audio Research D250... but that's just me. I know many people post things like "well, with a speaker that has a flat impedance curve everything changes, less power is needed, yada yada yada" IMHO, this IS true, but 30 watts for ANY speaker that is 81db efficient just ISN'T enough. From personal experience with Magnepans (quite flat impedance curve) that were either 84db or 85db efficient (in other words they required about HALF the power of your 81db speakers for any given volume level) I was never satisfied below 100 watts/channel, with very well designed, high-headroom tube amps. Other folks will say that it depends on THIS, it depends on THAT, but if you are looking for "bass extension" and "good dynamics" 30 watts simply WILL NOT drive 81db speakers. I have heard it over and over-- even a friends pair of Altec 287F 75wpc (conservative) amps that used a PAIR of type 845 transmitting triodes at 1150 volts on the plates only sounded punchy with speakers 85-88db and up. I am a 20+ year veteran of tube audio and have heard many "wishful thinking" combos of SET or parallel SE amps driving everything from Wilson Watts, Tyler Acoustics, UREIs, Quad ESL 57s and Quad ESL63s.. and just when the sound was getting sweet and rockin' the amps started rolling off the bass and treble, then outright clipping. MAYBE possible if your speakers were 84-86db and you ONLY listened to female vocal and classical, (and your speakers had a perfectly flat impedance curve-- very rare!)but I just think you would be pullling your hair out with this combo. I'm not trying to be an asshole here, just sharing long experience and informed opinion. Hope this helps, and sorry if I bummed you out!

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