Preamp or Amp?


I started a thread that has gotten no responses so I've started another one. Hopefully this is much more direct. I have a simaudio intergrated amp. Would I hear a difference moving up from an i-3 to a higher i-5 or Classe' 151 OR would I be best to move my budget up slightly and begin the trek down the seperates road.

Does the Preamp effect the overall presentation of a system more then the amp? I will be using Polk Audio LSi15 speakers. At what level of separates will I hear a significant improvement in sound quality? I've been doing some light reading, and have read up on some preamps the Copland 305, some CJ units...regardless of what I buy down the road, it will be used. Can a Jeff Rowland concentra or SimAudio i5 really keep up with most separates? I've been told by a few people they can. I'm not sure if it matters but the source is a John Wright modiffed Museatex DAC/transport combo.

I like the idea of simple one box solutions, not to mention the money saved on wiring. But a few people on this forum have told me if I like the sonic signiture of the LSi speakers, perhaps maybe it's time to look at getting a dedicated amp/pre-amp for further improvements, if thats the case which should I get first, the amp or preamp?
lush
Forgot to say...

Are the LSi15 one of the bigger bargains in all of Audio or what??

Its funny cause a lot of people would just dismiss them because of their brand name. I auditioned a pair of Sonus Faber Grand Piano speakers. Couldn't justify selling my Polks to by those. In fact, I downright preffered the Polks.
I've heard the SimAudio i-5 might be spec'd lower then the i-3 but draws nearly double the current and is a much much more powerfull amp then the i-3, I'll look into the perreaux's, they seem up there in price, perhaps used.
I forgot to mention...

I spoke to Paul DiComo (VP or Press relations at Polk Audio) once, and he mentioned he liked the sound of the LSi 15s paird with an Ayre AX-7 integrated amp a whole lot. That amp is not all that powerful...

Anyway, I can only say from having tried a few different amps, they like power.

As far as the I-5 drawing more current, it doesn't make the amp more powerful, it makes it less efficient. It may be that every section in the I-5 is biased higher than in the I-3 does making it draw more current. Having said that the output power of the I-5 could still be less than that of the I-3, as specified. Regardless the I-5 its still a more refined amp, and if your room is of medium size the I-5 it shouldn't run out of gas.

The thing I like about the Perreaux is mostly the control. If paired with the wrong amp the LSi15 could sound a little loose on the bottom end. Which is why tube amps are a no-no with those speakers. All Perreaux amps have really low output impedances, making their damping factors real high. All this means that the amp is always in control of the speaker drivers. Bass is tight, and very musical. The midrange and treble are clear, detailed and smooth.
The whole system is a synergy of wire, resistors, caps, etc...each playing some role in the over-all sound. Each component can make a difference, including the wire. Amps can give you more or less of what it is being fed, but pre-amps seem to give depth, attack, pitch [speed], soundstage effects more than other electronic components.

A top notch pre amps abilities will not be fully realized with a sub-grade amp or speakers, or with sub-grade interconnects for that matter.

This is the audiophiles dilema and the audio products makers cash-cow.
In my experience, changing the preamp has made a significantly larger difference than changing amps. There is a lot more circuitry in a preamp and the voltages are low-scale so this adds up to a bigger difference in sound quality realtive to design and build considerations. my 2 cents! Arthur