How important is the pre-amp?

Everything matters but after 3 decades and God knows how much equipment I firmly believe the preamp and source are super important.

A preamp can make a big difference - positive or negative - in my experience.

This weekend I auditioned some equipment for my system.  I am interested in purchasing a more powerful amplifier.

My situation is I have a McIntosh C 2600 preamp and McIntosh MC 302 amp with Moon 280D DAC and Rega P8 turntable.

I chose to listen to McIntosh MC462 and Moon 330A (with the intention of buying 2 and using as a mono block. 

The test system was McIntosh C2700 with the Moon 280D and Rega P8.
 I also had Moon 390P available to listen to the impact of the improved DAC and the difference of a solid state preamp.  My rationale was to test any synergies of using the same brand.

My experience was unexpected:

1.  I preferred the Moon amplifier.  I felt it provided more details especially with delicate sounds or when there's a long of different music going on such as part of David Bowie's Let's Dance and during Black Sabbath War Pigs.   I felt the highs were a bit 'brighter' with the Moon.  Potential for harshness so I listened to a variety of recordings and my conclusion was the McIntosh provided a bit more mids such as around voices and there was less clarity when things were busy.  The Moon was better and having congruent yet details in all the music. 

Given that I did a sound comparison between using just the Moon amplification. 

2.  Tested the sonic difference between Moon 280 D and Moon 390 just as a DAC.  The 390 has more detail - aligned with the product placement.

3.  Used the 390 as a preamp instead of the McIntosh.  The sound impact was more details and delicacy.  I recently upgraded from Sonus Sonetto V to Olympica Nova V - the clarity in details was that significant.  Note preamps are different philosophy tube versus solid state.  

My take away- preamps make a difference as does the whole system (Millercarbon states it regularly and I observed it as well).

Can a quality integrated amp sound great?  Yes and better is going to be a personal preference. 

Enjoy the journey. 

Thank you all for the super interesting responses, just what I was hoping for.

I liked the point that a perfect preamp would do nothing to the sound, but what would it cost? Maybe my 1K preamp is far from what it could be. 

A general theme appeared to me that people found running without a preamp made their system sound a bit weak, undramatic. I had noticed this myself years ago, but thought that was just me. Now I have long interconnects (balanced) between pre and power so I can see that I need something to drive that cable.

I think my next treat will be a decent preamp. I am going to hunt around for one with a MC phono section but without an inboard DAC (as I think that technology is still changing fast, and I like the idea of keeping the digital stuff out of a mainly analog box). Something that feels classy to use (as the preamp is mainly what one touches). 

Thanks all for sharing. 

Now I have long interconnects (balanced) between pre and power so I can see that I need something to drive that cable.

I don't know of a preamp that cost only $1000 that supports the balanced standard. Since you are driving long cables what you might consider is getting a set of Jensen transformers to sit at the output of the preamp and then have them drive the cables properly. You might be surprised at how well this can perform. You can do this with a single-ended preamp too.

I'm assuming that the amplifier has a balanced input. Its easier to build a balanced input that supports the standard than it is to build a preamp output section that does the same thing. So you may not need transformers at the input of the amp(s).

If you do try this, the output of any line transformer has to be loaded for best results. Jensen Transformers can advise you in this regard with their product, as should any manufacturer of a quality line transformer.

Passives seem to have the edge with faster transients and a somewhat leaner sound.
We need a contribution here from georgehifi.

Back from holiday.
Look at it this way if "going direct", "going passive", "going active" all drive the amp/s perfectly, with no impedance or voltage restirictions.

The one that sounds closest to a piece of wire is the best, that’s the "direct" next best is the "passive", then the "active".
Going direct imitates a piece of wire with no colourations, next is passive, last is active as it has the most colourations/distortions.

Cheers George