The reason you probably didn't get much response is that its tough to do short of writing a book. So much depends on something very personal to you...What do you really want to get out of your system and how good are your listening skills. By way of example.....
I've have a good system, good listening skills, and reasonable expectations and am quite satisfied with the components I use, all seperates, because of the flexibility it allows me, as well as the quality of their sound and the synergy they create. I recently purchased an inexpensive, medium powered tube integrated, thats sort of idiot proof but can easily be voiced by tube rolling, and when I'm not listening very carefully I don't know what I'm missing, and for a more casual listener I quite confident they might actually prefer this little integrated.
You have mentioned the "sonic signature" of the Polks. For those of us who haven't owned them, or listened to them extensively in our own rooms, what exactly is their "sonic signature". When you can answer that question without describing your electronics or the room you are hearing the speakers in or their set up, or conversely describing all of those things exactly, we have a starting point.
Perhaps you could re-think your question and rephrase it so that specific answers are possible. Folks here usually chomp at the bit to give advise............
The LSi's are very detailed yet also very warm. SMOOTH is the best word I could use to describe them. Much much smoother then the B&W's, Totems and Paradigm's I've heard. Higher frequency's simply seem to float through the air.
I've owned and/or demo'ed 6 or 7 SS amps and 7 or 8 SS and tube preamps in the last 4 years.
My experience is that for the most part, preamps with a decent or better reputation are for more similar than they are different. Aside from a couple that were simply way too subdued regarding detail and resolution.
My experience is also that for the most part, amplifiers of a decent or better reputation are much less similar in characteristics. In addition, there appear to be far greater compromises with amps. For example, one amp may have an almost sweet presentation with excellent transient speed, yet severely lacking in the lower bass regions where the bass was ill-defined and compressed (it was a Sim Audio product). Or another amp that had pretty good bass definition (still far from the best) but was out to lunch in the upper frequencies.
To find an amp that does it all is rare, but they do exist.
Therefore, I'd focus on the amp first and foremost. Over the preamp and every other component, speaker, cable, or room.
If you intend to stay in your current budget, I'd highly recommend researching a used McCormack DNA 0.5 or the DNA 0.5 revision A amplifiers and perhaps a used Pass Labs X 2.5 preamp.
To the best of my knowledge, there are very few amps that can even begin to approach the sonics of this little amp.
But there are also a few very good integrated amps. For example, supposedly the Audio Refinement Complete is quite inexpensive and very first rate.
it is all combinations, but I am going to disagree with the above, I have found a bigger difference in preamps, althought I have heard big differences in poweramps,but the pre amp comes before the amp, so its sonic signature is going to be there no matter what amp you hook up to it. BUT the are a combo so both are very important.
IF YOU ARE NOT INTO TUBE S.E. AMP AND A FULLRANGE SPEAKERS,THEN YOU ARE MISSING A LOT.TRY LOWTHER YOU WILL NEVER ASK FOR ANYTHING ELSE.
Preamp over power amp. I am not that familiar with your equipment. However, as a rule of thumb... A Preamp upgrade, whether it is a stand alone component or within a higher quality integrated, is the fastest way to the pot at the end of the rainbow (At least in my experience).
The right preamp CAN make an astonishing improvement . To comment on a reference to Totem speakers above , i have found every model the company makes to be smooth and grain free . There is not a dud in the entire line .
In my extensive personal experience, the PREAMP makes the biggest difference sonically.
They all sound vastly different, and they can make or break a system.
I have had more frustation over the right preamp than any other components in my system, by far!
Power amps can also make or break a system, but not to the degree that a preamp can in my own personal experience.
The only other component that can make as big, or bigger, sonic improvement than a preamp, IMHO, are the loudspeakers.
Just my 2 cents.
I'm going to make a suggestion that might be so obvious that I'll get hooted off the board. If your current integrated has a capability to separate the pre and power sections, perhaps you could work with a dealer and get some pre's and amps that fit your budget to demo. Try a pre using the inputs to the power amp section and then compare the sound to using the pre-outs from your integrated with a better power amp. The comparative results might tell you where your money could best be spent. Then you can stagger upgrade purchases appropriately to get biggest sonic bang for your budget.
Brainwater: I've heard many great things about the Totem lineup. I've heard the Mani2's powered by Simaudio Celeste and wasn't impressed at all, even the owner of the Totems prefered the LSi's to his older Mani2's. Perhaps it was the mix, but I found the presentation to be stale, the LSi's really bring you in. I can listen for hours.
I've always been a source first guy, hence the reason I've spent so much (or little depending on how you look at it) on my redbook player, to ensure everything upstream would benefit. I really don't know what kinda level of preamp amp I would have to get in order to best a top flight intergrated like the Simaudio i-5 or Classe' cap 151 any suggestions?
I am going to step quietly back into this . I have just purchased the CJ Premier 350 solid state amp. I have never been as shocked by a solid state amp as i am by this thing. I have always had a more signifigant impact by preamp upgrades ... till now . I now am rethinking my theories .... again.
It makes sense that a Preamp will make more of an impact. They "manage" signals that are very small in magnitude and amplify them to drive amps. If something goes wrong at that low level of magnitude, once you amplify it, you'll also amplify the "mistakes" made. Most audio-designers would say that is a lot harder to build a proper preamp, than it is to build a proper amp.
As far as the I-5 Vs the I-3 goes...both are good amps, the I-5 is more refined though. On the other hand, as an owner of a LSi15 pair, I can tell you, they like power. They like an amp that can take control of them. So in that sense the I-3(since is a bit more powerful than the I-5) could be a better match. I would suggest trying something even more powerful. If you like the convenience of integrateds(as I do) and need something powerful, I'd suggest check out the Perreaux integrateds. I've had the Perreaux 200iP, and now I have the Perreaux Radiance R200i(both are rated at 200Wpc at 8 Ohms and about 350Wpc at 4 Ohms), and I'm very happy with the results.
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