Which is more important? Amp or Preamp?


Would upgrading the amplifier or preamp make the biggest sonic difference? Here's my scenario. I currently own a HT setup. Previously, I had what I considered to be a decent 2 channel system (Classe amp and preamp) but wanted to move into HT. After having gone on a recent tweak-fest with cables, power conditioners, power cords, and isolation devices, I only realize now how good two channel sound can be. So what would my next logical upgrade be? I'm considering two options: First, purchase a considerably better 2 channel amplifier for my front speakers for two channel listening (and using the current multichannel amp for surround sound) or option 2...look for a better pre-processor which excels at two channel reproduction. In the end, two channel is more important to me than HT, but I do want the convenience of having HT without having two systems. Here's the list of my current equipment:
Rotel 1098 preprocessor
Rotel 1075 multi channel amp
Arcam cd92 and dv27 cd and dvd players, respectively
PS Audio PS300 power regenerator
PMC OB1 front speakers (along with various B&W surround speakers)

I'm looking on spending around $2500 for my upgrade in the USED audiogon market. I'm leaning towards the 2 channel amp upgrade (YBA, Ayre, Bryston, etc), thinking it would make the biggest difference, but I'm not sure. Any suggestions or recommendations for amplifier or pre-pro upgrades would be appreciated!

Thank you!
calgarian5355
Calgarian, it doesn't look like you're getting any replies so I'll offer some comments, and hopefully others more knowledgable of the tradeoffs in trying to do an effective surround sound set-up will weigh in.

In my opinion, you've identified the critical issue: getting really good two channel sound, then going for the extra channels once that's accomplished. I think your instincts are correct to focus first on a good two channel amp. Rotel's own 2-channel amp is likely to have better sound quality than their multi-channel amp: just getting the power supplies right takes chassis space and significant parts. This is something Rotel usually does well, but I can't imagine they haven't had to make some compromises on this in the multi-channel amp. Many excellent alternatives exist for you to consider, as you've mentioned.

As to the preprocessor, there certainly are excellent sounding 2-channel linestages that will be superior, but it won't be *just* because they are 2-channel. Some linestages may not sound as good as your current preprocessor, so I recommend you apply some critical thinking and *listening* on this element of your system in a next phase.

There are several members on Audiogon who've assembled superb 2-channel systems to which they've added the surround sound processing capabilities for those ocassions when that option's desirable. Albertporter has posted a couple of times about how he's accomplished this in the world class 2-channel system he uses.

Good luck!
In my experience a preamp upgrade surpasses an amp upgrade. Search the archives on this question. Volumes have been written. My $.02 = Buy a mint-used $1,500-$2,500 tube preamp of your choice. Use the preamp 'main' RCA outputs from your Rotel processor into your tube preamp for HT. Run your CD player or other 2-channel material directly to your 2-channel preamp and your miles ahead of where you are now even with your existing Rotel amp.
Pre vs. amp depends, but some amps sound pretty similar. I've heard large differences in preamps (and amps too), but mid-fi amps can sound somewhat alike.
Why not invest in a Meridian 565 DD 5.1 processor unit? Many will swear that the sound in 2 channel is on a par with a very good pre and they can be obtained fairly cheaply, plus they do DD as well.
I have a 568 and use it for two channel -- it sounds considerably better than many processors I've been exposed to.
I certainlly agree with Maich with re. to the 565. The plain 565 does not do DTS;that requred the z3 upgrade. The sound quality on this piece is only limited by what amps and speakers you pair with it.--(Yup,had one.)