QUOTE (muzzy66 @ Apr 14 2007, 06:02 PM)

Ahh yeahhh Milbert. I knew I forgot one

ahh yes, the 'flux capacitor'
Analog amplifiers are not what they used to be, and neither are tube amps - the days of noise, hum and waiting an hour for the amp to warm up are mostly long gone, unless of course you still love using old-skool gear. The improvment in technology has brought tubes a long way, some would say to the point where the 'tube' sound has lost it's soul and character - because of the electronics evolution.
I say there's a place for everything and everything in it's place. Sorry tube amp fans, but I firmly believe tube amps belong with fender stratocasters, gibson les Paul's and 335's and SG's where they were 'born' into the music world, and their 'sound' came from the guitar players who plugged in and turned them up.
Yes, I love the sound of a tube amp. BTW, tubes cost a sh**load to replace these days, and they're getting real hard to find. Exact replacements are what you need too, not some generic one. there's a lot to be said for different tubes, more than there is to be said for different models of different brands of car audio power amplifiers. (They've been around a lot longer too)
I've got a different take on music than some, maybe it's because I'm a muso. ?
my take is simple. You use the tools to create the sound you like (tube preamp / line-driver etc, plus effects). You take that sound (a sound you 'like') and record it with analog or digital gear, depending on your budget. how much of an audiophile or perfectionist you are becomes obvious at this stage, not so much later..
the source is what you have to work with, isn't it.... so for this example, I'm eliminating all the variables here and will state that the result for this particular example that i'm putting forth is an accurate Digitally mastered signal.
or if you like in cd-speak a DDD recording.
What you do after that, depends on how you want to hear it. tube amp / digital amp..... it's personal.
however if we talk about accurate reproduction, that also means adjustments in the car for EQ, TD, sibilance and a bunch of other factors, over and above adjusting the amp's linearity (or lack of) on output.
again, the advantage here is that a non-tube amp suffers less from 'walk' (the change in sound as the valves warm up and cool down, how much power is applied etc) Walk is hard to adjust for, because it's never exactly the same, the flux is variable on a magnitude far greater than solid state gear.
Let's not overburden ourselves with a discussion on solid-state amps with tube preamps just yet, ok? read on...
So for SQ, for 'reproduction' of the sound, you want accuracy. Accuracy is Zero or One. thats a digital signal, as far as you can use it. all the way to the amp if you can, and yes you have to use analog to drive the speakers obviously, but that reduces your weaknesses in a system to simply the d/a converter quality (components- head unit, amp- the digital source) and speaker quality, install quality and the quality of the recording.
So I use D.O output from my 'headunit' into a D.O input on my Focal DM. No rocket science there. The signal from the mac is digital optical all the way to the amp's D/A converter. Thats just reducing the physical layer complexity to the lowest common factor. less bits equals less possible sources of distortion.
But the difference is that I can know exactly what the signal is going in, and I can measure the signal going out and directly compare the waveform.I know what output waveform to expect for a given input, and if I were perdantic, I'd correct any anomalies there. Then I'd measure same with the speakers installed and compare the waveform and adjust the level and eq accordingly, because I know what the input is and know what the output should be in proportion.
This is so much harder to account for with a true tube amp because of the 'walk'
as an aside, many digital amps have some very tricky circuitry in them to stop the harsh 0dB 'clip' and now scale the output waveform so that the peak amplitude is a fraction under 0dB, meaning you get the same waveform 'shape' without the loss @ the clip level. analog amps don't clip, they just drive the signal into distortion, so this is where many people perceive the tube wins over solid state.... and yes, it could, but you have to control the input and output gains so much more tightly, and always drive the signal with the least amount of power necessary to achieve the level you want. way harder to do on a true tube amp.
So thats about as pedantic as I get. some days I don't give a toss, and love to enjoy cassette hiss, because there is something about an analog recording or just plugging in and ripping it up that appeals to some visceral nerve.
That also happens to be where the rolloff between SQ and SPL Junkie seems to occur.

I don't believe there are any hard and fast rules in what amp you use, what headunit you use. you have chosen some awesome speakers, now the trick is getting the best out of them by tuning them to your car's environment.
oh and guess what. it won't ever be perfect, because we are human.
Just enjoy the sound for what it is, and tune it as best you can, using whatever amplification you like/can afford - and if you're not happy get a pro to help.
Thats what I do anyway.
(edited for some really bad typos, left the less important ones)