Dear Joe: Your question is a very controversial one: +++++ " How much of the front end depends on the preamp . " +++++
Analog front end?, I want to do easy: TT, cartridge/tonearm and phonolinepreamp. I know that we have to consider cables, platform, electric energy supply, etc, but like I say lets do easy.
All de links in this analog chain are really important and critical, how much important/critical they are: well, for this question we could have several/different opinions like the number of people that give an answer about. I think that there is no absolute answer only a relative one according our experiences and each one priorities.
In my case: 20% to TT, 35% to cartridge/tonearm and 45% to phonolinepreamp. I know that for other people the TT is more important that the cartidge/tonearm combo, here it is what I think about: the cartridge/tonearm combo is the analog audio link ( front end ) that has the task to track, " read " and translate properly the record information, all this task depend on the good match of the cartridge with the tonearm characteristic. I know that if we don't have a TT those cartidge/tonearm tasks can't do it, but the issue here is that the transducer is the cartidge it self: that's the high importance it has. I can give you an example: if you change your Rega TT for a better one maybe you could hear a little improvement in the quality sound reproduction but if you change your Rega cartridge for a better one you should hear a higher improvement on the quality sound reproduction, no doubt about.
Now, the phonolinepreamp has not only a very critical tasks but a very hard tasks.
The Phonolinepreamp has to amplify that very low level signal that comes from the cartridge&tonearm and has to amplify it with out noise&coloration&distortions in any way. Only for you can feel the weight of the phonolinepreamp work I give this example>
a moving coil cartridge that has a 0.2mv of output level needs that its low level signal be amplifyed 10,000 times , that is for 2 volts for an amplifier can runs the speakers. 10,000 times !!!!!!!!!!!!, just imagine.
This is the critical task for what we are talking about.
But it is not only this amplify task with out noise&colorations&distortions what the phonolinepreamp has on target there is, at least, another more critical issue> the inverse RIAA eq. curve and its accuracy. Almost all the LPs were cutting according the RIAA eq. standard curve where, in an easy explanation, the bass frequency were down in volume around 20db below the original and the high frequencies were over around 20db higher than the original. This up and down changes conform the RIAA eq. curve that afect the whole frequency range. This RIAA eq. curve is extremely accurate and the phonolinepreamp has to mimic this RIAA eq. at inverse, that-s means that the inverse RIAA eq. in a phonolinepreamp has to return the bass&high frequencies at its original level, meaning that after the inverse RIAA eq. the signal should be flat with out any deviation. This phonolinepreamp work is a task that only a few phonolinepreamps can do it with low deviation from the RIAA standard>. This deviation should be no more than 0.05db from 20Hz to 20kHz. Which of the phonolinepreamps that everybody use meets these critical and audible spec. Think about.
Regards and enjoy the music.
Raul.