Which has greatest influence?

I have recently upgraded my amp but got to wondering which really has the greatest affect on the quality of sound --the preamp or the amp? Or is there a difinitive answer to that question" I have heard it said that your s ystem is only as good as youre weakest componet. Is this always true?
No, there is no definitive answer. The amp/speaker pairing is paramount. amp/pre impedance matching is usually not an isuue, but when it's bad, it stinks. Trying different combos is the only way to know what has greatest impact in YOUR SYSTEM. Cheers,

Each component contributes a different area of quality to the overall sound. There is some overlap, of course. Amps and preamps both contribute to dynamic range and resolution, frequency extension, clarity, musicality, smoothness, etc., etc. But an amp cannot increase the resolution over the signal it receives from the preamp. Likewise, even the highest resolution preamp, while preserving signal integrity and passing it on to the amp, cannot control the speakers or deliver the current to improve linear behavior at all frequencies. That's the amp's job.
There are great amplifiers and great preamps. If I had only one choice it would be the preamp FWIW.
Actually it's neither,look to your source that's where it all begins.
The amp/speaker interface is the most important interface (or matching) in your system, right up there with matching cartridges and arms on a TT set up. But once you get that down, the weakest link in the chain saying applies.

FWIW, if I were starting out fresh, or all over, the first component I would buy would be the 'best' pre-amp I could afford and build my system around it. That said, if I were buying new speakers for what ever reason, I would always assume I might need to buy a different amp, just as if I were to buy a new cartridge I might have to get a different tone arm or phono stage.

Just my 2 cents.
Switiching to a tube Pre-amp gave me the most satisfying change in my system. This particular component was the first major upgrade in my starter audiophile system after reading lots of replies to a similar question from earlier forums.
All things equal, given only one choice, I'd get a better pre-amp first.
I would say the amp/speaker match is the most critical, get that wrong it doesn't matter. Get that right and most decent preamps and sources will be ok, and only better as you upgrade, but nothing will ruin things faster than an amp and speaker that do play well toghether IMHO.
Thanks for all of the thoughtful answers. My setup at present
starts with a Prima Luna Pre amp, I recently added Conrad Johnson LP 705. Speakers are B&W 804s. The CJ impreoved my system greatly. Just wondered if I changed the Preamps would I get a similar boost?
Wondered too about matching preamp and amp CJ all the way. would that make a difference? I am somewhat new ro all of this and these questions pop up in the middle of the night,
I use the PL pre-amp in my system. Specifically what was the 'boost' you refer to. Can you describe the sonic differences it brought? What further improvements would you want to bring about by changing the PL3 out. Having some knowledge about the PL3 and how it interfaces with some amp's I might be able to help. BTW, what is you amps input impedence. I'm not familar with the CJ LP705.
#1- Speakers
#2- Source
#3- Preamp
#4- Amp
#5- Wire/Tweaks/Room etc.

This is true provided that all componets are of a reasonable level of quality and the room is of an adequate size! There are exceptions of course.
All components matter, which is why we build systems. Component switching can improve or degrade systems, but there is no predictive formula that tells us we will improve things with a certain amount of dollars spent. This is the chase to do as much improvement for as little $.

Also the ears, brain, emotional state and physical condition at any given time will determine in part how we perceive our systems to sound. And then there's the room...

Nice setup and I like the CJ addition; they make great gear.
I am a hater of Pre-amps! after 20 years of playing around in this wonderful hobby I have learned that pre-amps have the highest potential of messing things up.

Let's say you find your dream source, a great amp/speaker combination and a room that cooperates, all that can go to hell fast with the wrong Preamp. They are necessary for switching among multiple sources (most systems for sure) and to "attenuate" the playback level (90% of the time) and occasionally amplify the input level (10% of the time?).

My most satisfying solution has been the use of a passive pre. I am currently using a Luminous Axiom pre which is nothing more than a potentiometer shunted to a quality resistor. No switches what so ever in the signal path. I believe they do offer models with multiple inputs if needed. Most folks shy away from passive pre-amps because they are not as straight forward to apply. I have had terrific results with many amp/speaker combinations as long as you follow these simple rules:

Keep the interconnect runs short
Use amps with the highest possible input impedance (30K or higher, 100k best)
Use amps with an input sensitivity as low as possible (say 1 Volt or less for full output).
Source with 2 volt outputs or higher (most players)

What that means is if your amp is rated to put out 100 Watts at 1 volt and you run your CD player directly (or through the passive pre) at 2 volts you have more than enough to drive the amp to more than full rated output!

What you get is the least messing up of your source signal. Having said all that, there are excellent active preamps out there that don't mess up the signal AND make the sound more dynamic with slightly more detail due to the fact that impedance matching is no longer an issue and the signal goes through an amplification stage (only to be attenuated again!). Good preamps tend to be expensive.

Pick the best source
Don't mess it up with the pre
Choose an amp with the sound signature you like and enough power for your speakers/room
POSITION your speakers for best sound, this can be a drawn out effort.

The end of Bokfudo's post nailed it. During my long since past audio career - it constantly amazed me how often I'd sell some at least decent speakers to a guy and then find out they'd been set up in some absolutely bizarre configuration.I am also completely convinced that the classic British approach to a HiFi system is most likely to lead to a great result : Listen to and then buy the best source you can possibly afford , try and get some electronics that will work with the speakers you like - but the speakers will probably continue to sound better and better as you improve the rest of your system.
For instance - many years ago at the Polk factory I briefly heard the smallest and cheapest speaker those folks made drivin by a system that included a pair of Threshold Class A Monoblocks - I had listened to those speakers both in my store and customers homes a lot and to be honest - wasn't terribly impressed- wow - given simply outrageous stuff pushin 'em - these were wonderful speakers.
Stonedeaf, Amen to that. Good upstream equipment can make relatively inexpensive speakers sound great.

Jacknorth, Before going out and spending money on new electronics you may want to try some Elrod cables, power and/or speaker. I installed them and it was like putting in a new upgraded component.
Only as good as your weakest link, hard to answer. Lets say you had nice equipment and speaker cables were the weak link, I think the system could still sound fine, you may not even be aware the speaker cables are the weak link. And so some things are more important than others, and yet they're all important. I'm trying!

Having to choose only between amp and preamp, I would have to choose amp. I say that because amps have to interface with loudspeakers, proper synergy is of utmost importance. Amps also just seem to give the most 'flavor' to a system, think about all the different tube configurations possible.
IMO, all system components should be matched as to level of performance. A $20,000 preamp will make little or no difference in the SQ of a $5000 system.

However, the speakers need to be driven by adequate amplification. That is more important than the preamp as far a SQ goes. Once that is achieved, then attention can be given to the preamp. Unlike an amp or the speakers, the preamp will determine the type of control one has over the system. Does one need tone EQ, remote control, phono input, computer input, headphone output, etc...?

Having just upgraded my amps and then my preamp, I found them to be roughly equally important, but each effected the system in profoundly different ways. For me it came down to what the amps do and what the preamp does not do. My new amps control my speakers much better than the old amps did. Bass is tighter, deeper and more focused. Dynamic range increased as well as improved soundstage size and definition. My new preamp gets out of the way much better than my old pre did. It is quieter and more neutral. Micro and macro details improved, timbre and transients improved. However, each upgrade made the listening experience more involving in roughly equal amounts. They are from the same manufacturer, so they work very well together. My system is built around my electronics. Its the only area I have really upgraded over the past six years.

Having said that, I have found the most critical component/relationship is the room-speaker interface. This is about scale, placement and taste. Then the speaker-amp/cable. And finally the amp-preamp. The front end is a completely different thing and can be thought of as its own system(especially analog). It can be of equal or better quality but is not as interdependent as those other components are and can be thought of independently from the rest of the system.

At least, this has been my experience having just upgraded my electronics.
Which has greatest influence?

In response to Newbee: You asked several questions in your post which I will try to answer: Re What I meant by 'boost' I wish I knew the vocabulary of the audiophile. It simply opened a richere, fuller sound, larger soundstage, a feeling of being closer to the real thing. I was just wondering if the changing of pre amp would open that door even wider. Sorry my finger slipped when I tried to identify my new amp. It is a Conrad Johnson LP 70S.
And I think the impedence rating is 100. Would appreciate any thoughts y0u might wish to share wirth an old duffer who just t`urned 90. Jack North1178
An old duffer who turned 90 or finally hit 90? More likely the latter I think. :-)

I do believe you could improve your systems sonics with a different pre-amp.

I use the PL3 with a PL5 and combined they are excellent lacking only a little bit of ultimate resolution and deep bass power. BUT, seperately, the PL5 is deficient in the bass when driven by other pre-amps I've tried, and the PL3 is somewhat dark and closed in with the other amps I've matched it to, including tube amps with a high input impedence (I assume yours is 100K, not 100, and a technical impedence match would not be a problem).

Now what pre-amp and how much money you might want to chase after it is another thing, but you should try some out. You might try out one of CJ's pre-amps that compliment your amp.

Hope that helps a bit.
Thanks Newbee. No - had ny 90th in July. Tell me, when you go to matching pre amp to amp what are you matching? Are there som specifics to look for? Jacnorth1178
I have read all the above responses and I believe all pieces in your system are important. Proper line conditing is just important & will make your system sing.
I have heard your amp and I own a CJ preamp, a CT5 would be a great match.
Jack, what you are 'matching' for the most part is pre-amp out put impedence (low is good) and amp input impedence (high is good). Too high an output impedence from the pre-amp and too low an input impedence in an amp is not so good, it will roll off frequency extension, highs and lows mostly noticible in the lows. The other thing you want to consider, and involves speaker efficiency is the amount of gain from the pre-amp, this input sensitivity of the amp, and the speaker efficiency. You don't need (or want) a lot of gain from a pre-amp if you have an amp which has high sensitivity (a low(er) number) and or speakers that have high efficency. Its all a balancing thing and your dealer should be able to help you to get the 'numbers' all lined up.

Apart from that the only other thing to consider, and actually the most difficult for lots of folks, is tonal synergy through out the system and making sure that the clarity/resolution levels in your other components are not impeded by the sonics of the pre-amp you have chosen.

The good news though the sonics of the pre-amp are, or at least should be, the least problematic in setting up a system in the first place, and less difficult to introduce to an existing system.

I hope that helps you some.