Quick question. I have a pair of RT25i bookshelf polks. In their specs, it's recommended that I use an amp rated at 20-100 w/channel. Their nominal impedance is 8ohms.
As of now, I have a crappy Optimus (Radio Shack brand) pre-amp/amp powering them. It's a mere 25w/channel unit.
Now here's my question. I run a stereo signal from my computer's sound card LINE-OUT, into this Optimus pre-amp/amp, then into my Polks. Most of my music seems to play fine. I get occasional clipping in the tweeter with classical/vocal/piano music however (but not other types of music). Even when I lower the volume, I still hear the clipping (mostly trebles). Clipping which I don't hear in headphones, so I assume it's the ****ty Optimus unit being driven into clipping, not the speakers, correct?
Would this clipping be eliminated if I got a more powerful, 100 w/channel 8ohm amplifier like this?
Could I run a line out from my computer's sound card, directly into this amplifier, then out to my speakers? Or do I really need a pre-amp? (that would cost more $$ which I unfortunately do not have at the moment).
I'm ready to buy that Onkyo unit, but I thought I'd ask you whether it's my underpowered Optimus unit which is causing the occasional trebles to clip.
My second question. How is it that the 25w/channel Optimus unit can drive my Polks with great bass given that it's such a weak pre-amp/amp? Is this due to the fact that the line-out from my soundcard is already amplified?
I guess I'm just somewhat puzzled by the logic. I would think that if speakers are 100 watts each, then you need a 100 watt/channel amplifier, yet a 25 watt/channel amp, which I have now, powers them just fine.
In any case, thanks for any advice you may have.