what will make the greatest differance in sound.

I can only replace one item at this time. My system consists of Martin Logan Prodigy speakers, ML 336, Monster 2.4 speaker cables, Magnum Dynalab Tuner, Monster interconnects, arc LS1 preamp, California Audio Labs icon/mkii cd player. Feed-back from an earlier forum suggested I replace the preamp, cables and cd player. But which one first? I am considering a ML preamp 380s at some point, would like to know if this will improve the currant configuration and sound?
If you are planning to keep your Martin-Logan speakers (which are excellent), I think the place to start making changes is your preamp. After the speakers (which are transducers, and therefore the most subject to variations in sound between various types and models), the preamp is the most likely to impact the rest of your audio chain.
I agree. Dump the arc but also the ML 336. There's much better out there for less $.

There is currently a used McCormack DNA-2 Rev A amp for sale in audiogon.com for $4200. An amp that few solid state amps can come close to. And ML's are not among them.

I agree with the pre-amp, but I just can't understand with your list of components how the ML 336 could be a weak spot? You would just be exchanging one excellent amp for another. At their performance level it really comes down to personal taste, no one is really right or wrong.
Your on the right path...at some point garbage in gargage out...so I'd vote to start at the source. For the money, you CAL Icon is really good, I used to have one. But your speakers and amp are in a totally different league. One good option, if you are running mostly digital, is to go with a ML CD player. Sell the ARC and CAL, buy a 39 or 390s. Then, work on your cables, interconnect first, then speaker...

Going from a ARC to a ML 380S pre-amp should certainly make your system sound different, but whether it's better or not would be strictly a matter of (your) personal preference, and of course only you can decide that. Finding ways to audition such expensive equipment (in home) as the 380S can be difficult.

Years ago Monster ICs and cables did not have a very good reputation among audiophiles. It was generally considered soft, dull, and slow with rolled off HF. I'm not familiar with their recent offerings, but that would be the first area I would be suspicious of and want to address.

Why not give the Cable Company a call (www.fatwyre.com) and discuss ICs and spkr cables with them relative to your system, and BTW, you have some nice equipment already. Several years ago I bought all my Synergistic Research wire(s) through them-- after much home auditioning, and have never looked back. They gave me about a 15% price break. The home auditioning was worth a lot. Good Luck. Craig
Monster cables are the weekest link. You can sell the cables and get cheaper ones and still benefit in performance or just leave as is for less. In most of my cases I'm trying to stay as newtral(lo-reactance) as possible choosing interconnects and speaker cables. To me there are very few brands: Cardas, VanDenHul and AudioQuest that are worth paying attention even for the most cheap models. Among these three VanDenHul(if proper research is made) offers the most performance over a buck spent.

I also believe that source have to be the strongest link. The one I would recommend is EMC1
The least expensive upgrade is the cables. I agree with the preamp comments.
I would suggest:
1) cables first
2) pre second - if you liked tubes, you should probably give serious thought to a good tube pre and/or the Audio Aero Cd player
3) source last - Levinson 390s is quite good, but I personally do not like the 390-380-336 combo - I find it quite fatiguing - so I would break it up either at source or pre... I have found Levinson dealers are usually great about home demos, so (if possible) you should consider a home audition of the full set... and see if you don't feel tired relatively quickly too...

Good luck,
Several other considerations:
1. The listening room - are the acoustics of the rooms well suited to the speakers and their placement? Minor changes can yield excellent results.

2. Do you have a dedicated electrical circuit? Again, for small dollars, this will provide good results.

After these two things, many of the above recommendations have merit.

Happy listening, Joel
I owned the Prodigy's and loved them with tubed gear. I had them hooked to a Mac MC2000 and a Hovland preamp. I used Alpha Core Goerts M12 Veracity speaker cables (very inexpensive & good)and had a mix of IC's. My CD player was a Sony SCD-1, which is also quite good, feeding a Dodson DA217MKIID for redbooks. The combo worked quite well and was very musical, & with quality recordings, magical. The new Mac MC 2102 tubed amp is quite reasonable, especially used. See if you can get a dealer in your area to let you audition a good tubed amp & preamp combo, especially if you find the Prodigy's a bit dry. With the right gear, the Prodigy's are terrific.
IMHO the cables should be done last because they should complement the sound not define it. Your question was where should you start that will make the biggest impact.

This is like asking which is better solid state or tube. There are all kinds of reasons and all kinds of opinions but there is no absolute way to termining a clear winner. There is so much subjectivity and emotion in music what is one person's heaven is another person's hell. Just look at today's thread about ugliest speaker...some people say the Avant Guard's are ugly and one person sees them as art. Who is to say? Even though I think they are ugly...hey what does my opinion matter, whatever floats your boat.

A couple of comments below but I am not saying which should be changed first because order is like beauty. The CD player and preamp need to be addressed so just pick one and go (further comment on cables later).

If you are willing to spend the kind of money needed to buy the 380s then you can afford the best pre-amps in the world (bar just a couple of crazy expensive 2 box units). I think you need to understand what kind of sound you are looking for. There is no "best" in anything and you have started down a certain sonic trail by getting the Martin Login's and using the ML amp.

You may want to get more of the same or look for something that brings more warmth and richness to the presentation. If you don't have a dealer(s) in town where you can audition the equipment, you should be able to hook up with some store long distance that will accomidate your search. Unless you are bucks up and can afford to buy and resell you need to spend some time with the new unit(s) in your system.

Some of the hotest names in Pre-amps right now(all the same or less the 380s price range)are: Hovland, CJ, CAT, Blue Circle. Earlier this week there was a thread about a pre-amp many are saying is as good as you can get out there and it is only $2100-$2500. If I had the cash, I would look into this...http://www.cantech.net.au/~supra/preamps.html. See the thread "Preamp Deal of the Century".

All these companies are making world class gear so the choice comes down to one of personal taste. No one, no matter how well meaning, can tell you one item is clearly better than another. If it is better to you, it is better because your listening enjoyment is the most important thing.

It really is a toss up which is more "important" the CD Player or the preamp. Remember, a signal can not get any better once it leaves a component, it can only degrad less or have added "character". So, starting with your CD player, once it leaves the outs on the player it will never get better, and then once it travels accross the cable it can never get better. It may appear to be improved but technically it can not improve it can be altered but not improved. {actually it can't get any better than the software recording itself but you get the idea). There have been a number of good threads recently talking about the best in one box CD players which include discriptions of sonic characteristics. At this point you may want to decide if you want to do something with SACD or DVD-A and that will narrow your choices. I understand that you could get the best of both worlds if you buy the Sony SCD-1 and have it tweeked out (you can also find this in recent threads).

CD players....again, depends on how much you want to spend and what characteristics you want in your presentation. The Martin logins seem to like a lot of power so the ML 336 is probably a good choice as far as that goes, so if you like the characteristics of the ML then you are good to go. For me, ML sounds just a tad dark and all the times I have heard them they seem lifeless and all the ML gear seems to have the same signature. Now lots of people think they are the beat-all-to-end-all so this is just preference. I bring this up to illustrate the need to define what YOU like.

Even if you like the ML sound you may not want it throughout your system...you know, too much of a good thing.

As far as cables go, again, I have been taught that cables, racks, power management, and the like should be saved to finish out your systems unique sound. I am not saying the cable can't impact the sound a great deal, quite the contary it can have a big impact, however, if you start messing with the cables in the middle of your main component chagnes you will have a hard time seeing what piece is doing what to the overall sound.

Even with this said, you may want to buy some better cables than you now have while you evaluate because the cable you are now listening with isn't the best. You may want to start with midline cable from Van Den Hul or Nordost. Van Den Hul is little warmer and laid back (compared to Nordost) and Nordost is considered very netural and fast. Whatever you choose, make sure you understand the characteristic it will bring to your system and don't mess with them as you go through your review.

Good listening,
What a great response. It shows what a fine and and helpful group contributes to audiogon. You feed back and honest opinions are greatly appreciated.
A lot of responses, but you haven't stated what you wanted to improve, what don't you like? If you aren't even close to what you would like, IMO, speakers will easily make the most difference.

Are you wanting to upgrade just to upgrade?
I realize that the preamp and cd player are ventage. I am interested in reaching the potential limits of the prodigy speakers in accurancy (vocals)separation of instruments and pleasing smooth sound with great depth and three dimensional soundstage. The base response could use a little improvement. I am not a base inthusist but enjoy pop, vocals, instrumentals and the 70's & 80's music soft rock I grew up with. I am not someone who has auditioned many conponents nor will. I am looking to invest in one conponent upgrade to move in the direction of these these sound attributes. I am not a trained audiophil owner. I just like music. Opinions are all i have to base these decisions on and appreciate the opportunity through this forum. Thank you all.
All the units we talked about are good but it sounds like you want an example with little or no hassle. If you get ML preamp you will improve in all these areas and it is built like a tank and has the coolest volume knob in the business (and the best read out). You could save yourself quite a bit of money by buying the 38S instead of the 380S. You can pick up a 38S for $1900 to $2400 where a used 380S is $3400 and up.

If you want to stay with all ML the 39 or 390 are well made CD players and many think they are among the best. The transport tray is clearly the slickest one in the industry.
ML is known for service, reliability, and upgradability...oh, and the white gloves.

Now if it was me, I would go with the Mephisto or Electrocompaniet just for a change. The Electro is apparently better on bass but the Mephisto is warmer slightly more musical. The Meph is a sexy looking French top loader probably one of the best looking units in all of audio. The Electro is a top loader also and is quite nice looking in its own right.

Cables: I would recommend Nordost SPM (unless you can afford Valhalla but they are probably overkill) for interconnects and speaker cable. Many reviewer’s and phile’s reference. These cables are known for neutrality, speed, openness, and tight bass.

If you want to talk about other options email me and I would be happy to talk to you about options.

I always argue that speakers make the greatest difference in sound. That does not mean that you should go right out and buy new reproducers. You need to discover within yourself the kind of sound that you like. Do you want a warm, enveloping sound (heirs to the "West Coast" sound of our forebears) or something cool and reflective ("BBC monitor" sound) or something analytical and ultra-precise. I'm overgeneralizing madly, as someone will doubtless remind me, but I hope you get the idea.

My point is that the speaker, more than any other component, will establish the foundation for the kind of sound you like. Having set that cornerstone, you then choose electronic components consistent with your overall sonic goal. There's no magic to this synergy business, simply a clever and careful matching of the strong points of each link in the signal chain to yield an overall consistent endpoint without concatenating so many weak points that you have unacceptable defects in the finished product.

Listen, listen, listen. Not only to everybody's system you can get access to but also to as much live music as possible. Define your own tastes. Figure out how much you can spend. Buy what you like. Enjoy.

There are a lot of good suggestions. My suggestions are:
1. Get rid of the Monster cable, my god, you have a great system, this will give you a serious improvement.

2. You are kind of waffling between preamp and CD player. I think you should consider a CD player with vol. control, such as Wadia. The critique of these are that a low volumes they lose resolution. With your inefficient speakers, you will not usually be at the bottom of the volume range so you can really take advantage of "1 less link" in the audio chain.

Anyway this is just something to think about, plus you get to lose a box to make it less cluttered.