What is the most difficult component to upgrade

At least with a preamp, there are ways of acertaining just what it is doing in your system, if you can directly plug one of your sources into your power amp (don't try this before you have an idea how loud any particular recording will play in your system without attenuation, or unless your CD playback is equipped with its own volume control).

The most difficult thing to know what to do about when it comes to upgrading is cartridges, in my experience. There is almost never a good way to comparitively audition these - or often even any way to audition them at all. You're usually at the mercy of recommendations and reviews.

The preamp is a puzzler all right... why the heck should it make so much difference? After all, it basically just does switching and a little bit of amplification, as well as volume control. And then there's balance and... OK there's a lot to get right after all. My own preamp's manufacturer ONLY does preamps ( Klyne ). So the puzzler is which one to get, there are a whole lot to choose from and only a few are really great.

But IMHO the hardest thing to upgrade is a source component because ( as UHF pointed out to me when I asked them for help ) money spent here will not improve music through the whole rest of the system--just music played through that source. In fact a big upgrade to one source can even have negative effects : it can spoil listening to the others, as I found out when I upgraded my turntable.

And I think Zaikesman is dead right : who can audition cartridges before buying, these days?

The preamp is a puzzler all right... why the heck should it make so much difference? After all, it basically just does switching and a little bit of amplification, as well as volume control. And then there's balance and... OK there's a lot to get right after all. My own preamp's manufacturer ONLY does preamps ( Klyne ). So the puzzler is which one to get, there are a whole lot to choose from and only a few are really great.

But IMHO the hardest thing to upgrade is a source component because ( as UHF pointed out to me when I asked them for help ) money spent here will not improve music through the whole rest of the system--just music played through that source. In fact a big upgrade to one source can even have negative effects : it can spoil listening to the others, as I found out when I upgraded my turntable.

And I think Zaikesman is dead right : who can audition cartridges before buying, these days?

Preamps can make a HUGE difference in a system. Many audio people have told me that a systems sonic signature is many times most determined by the preamplification. I have had digital preamplification, passive preamplification, active SS preamplification, active tube premplification, and preamplification built into a DAC/CDP. All have their plusses and minuses. ALL sound very different, having their own general sonic attributes. And this is not even considereing the great differences in the sounds of the different brands of preamps in each category.

Long ago it used to seem silly to me to spend money on preamps. How much difference could they make? My first preamps were passive. Very inexpensive and in theory were supposed to sound good... Well I moved onto an active preamp (Morrison ELAD), a very nice piece for its price that offered a lot more detail than the passive pieces. Then I moved onto digital and finally to tube active. Anyway, the differences can be STAGGERING if your other components are as high of quality (in transparency) or higher than the preamp you are using.

My 2C

KF

KF I agree, the preamp has always made the biggest difference in my system the amp was second with source (digital) third. The toughest thing for me to spend additional upgrade money is cables. One I got to a certain level of cable any upgrade had little if any impact on my system.