Is the preamp the “heart” of the system?

Maybe the Pre is the heart. I tried the passive route after reading a lot of the arguments for going that way. But for me it was missing the life I get now with my tube pre and SS amp. Love the musicality, it draws me into the music.

The Heart? Yo could just as easily say the amp is the heart. In reality it is the Speakers that are the heart as they determine the type of sound you have more so than any other component.

I say it's the brains of your system it gives the orders you tell it to do.

I use a tube pre in a digital based system. I believe the preamp serving as the 'heart ' of a system stems back to vinyl/tape only playback. Now days there is more debate on this. That said I can't see myself going with a passive pre in this system.

@mijostyn  If we are using an anatomy analogy then the amps and speakers are more like the leg muscles and legs themselves. They won't do much if they don't get a signal- and the key to that is a good preamp, one that is transparent enough that a passive can't compete (there are also active preamps with which a passive can compete easily...).

Out here in the Pacific NW the hydroelectric dam is the heart of the system, pumping out the electrons the whole system runs on.

[1] SPEAKERS... 
 
[2] ROOM... 

[3]  GEAR... 

[4] CABLES...

Now replacing my Audible Illusions M3B with John Curl phono boards with an Atma-Sphere MP-3 to match my A-S M-60 amps.
I agree the preamp is the brain and that the amp is the muscle and the speakers the legs or the voice. Then the amp would be the air from the lungs.
Believe that a great preamp can transform a system!

I would say the preamp is more the spinal column. It links everything together. The DAC is really the "brain" because it is generating the decisions on analog waveform. The preamp or spinal column is just linking and transferring those messages to the amps / muscles.  The hands/feet are the physical speaker medium moved by the amps/muscles.  The "heart" is really A/C electricity. lol.

Pancreas?

Anyone?

I found preamp to have a bigger impact on sound than I expected and matching with your amps is critical.  I have tried eliminating it via the preamp stage in a DAC and found it was a huge step down.

The preamp May add colorations, be less pure, add distortion, etc, etc...  I don’t particularly care.  My desire is to have an engaging and enjoyable system that delivers an extraordinary listening experience.   The “purer” the sound tends to be the less engaging on many recordings.  

The electricity provides the nutrition or energy. PCs are arteries. The source is the brain, thoughts. The preamp IS the heart.   The ICs are then other arteries. The amps are the muscle. SCs are veins. The speakers are the lungs, vocal cords, voice. The music is the soul that ties it all together with the soul of the artist-musicians.

Yes !!!  I have had a number of DACs and while all sounded great my system lacked the scale it had with my c-j tube pre.    It just sounds right.....

noooo way....really?

being educated by this portal...I'd say...its power cords!

The preamp May add colorations, be less pure, add distortion, etc, etc...  I don’t particularly care.  My desire is to have an engaging and enjoyable system that delivers an extraordinary listening experience.   The “purer” the sound tends to be the less engaging on many recordings.  

You are correct compared to going amp direct, or using a "good passive pre impedance matched, an active preamp will add coloration's, distortions and also have less dynamics. 
If you need this from an active preamp give this to your sound, then I say do something about your source to fix the problem, and then flick that expensive active preamp altogether.
The old saying continues to be correct "the best preamp sounds like a piece of wire", guess what that's what going direct sounds is. 

Cheers George

coming from a cath lab background, the pre is the Brian’s of your system and the amp the heart or power.  Pre makes decisions and the amp will follow. But in the end, who cares what normanclature you use to describe your system, just enjoy and follow what your looking for in the end.

Pre makes decisions and the amp will follow

Ho dear!  and if the pre is not totally transparent and free of distortion as the best pre in the world is "suppose" to sound "like a piece of wire" it's said. Then it's coloring and distorting the sound of the source.
For it to sound like a "piece of wire" it would then sound like the source direct to the amp.

Cheers George 

YES

Yes, yes... a straight wire WITH GAIN!
Passives mostly have the straight wire part but not the latter.
But “uncolored” is highly subjective. I think that preamp manufacturers all have their own idea of what music sounds like and embues their pre with their “house sound”. Or “no sound” if you will.
But no sound is not necessarily desired. I think the safest and, hopefully, the best choice is to match the preamp with the amp by using units of the same manufacturer. I have found an amp in which I love the house sound, Atma-Sphere. I believe it is unique and special. So, I want to emphasize that sound by using an Atma-Sphere preamp. I think and hope that this match will be my destination units. And the amps work great with my speakers. Off the merry-go-round!

mglik OP
Yes, yes... a straight wire WITH GAIN!
Passives mostly have the straight wire part but not the latter.

Sorry but where have you been, you don’t need any more gain, as 99% of sources today have enough voltage output to clip any amp to full output, you don’t need even more from a preamp.
The reason preamps had all that gain was from the dinosaur era when they had phono inputs, phono cartridges need it.
There’s no need for any gain today, even with vinyl, as today’s separate phono stages have 60db even 80db gain, even they can go direct with a passive pre as the volume.

Nelson Pass

“We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”

Cheers George

Hi George,
You are right... kind of.
When I talk about gain, I actually refer to "meat on the bones".
I lived with passives for decades and when I finally tried an active, I will never go back. I am not a tech guy but I think that this aspect has a lot to do with an active producing musical information that could be referred to as gain.

meat on the bones

Simple, impedance match, just make sure the output impedance is 10 x or more lower than the input impedance, which it is in most cases with passive preamps and today's sources, and in nearly all cases of going to amp direct. This then cannot remove any meat off the bones.

Like Nelson Pass said above above passives.

"It sucks the life out of the music”, is a commonly heard refrain. (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”

Cheers George

I wouldn't say so. Speakers, power amps, room, front end, all far exceed in importance. Preamplification is: volume control, selecting input, and maybe making a delicate signal slightly more robust (especially true for phono stage).

Isn't it a an oxymoron to say:
"They  sound finally had meat on the bones and a musicality that I was missing. And it was just as transparent!"  
If it is producing a different sound, more "musicality," then it cannot be equally transparent, which would mean not affecting the music signal in any way. 

I think it's the pancreas of the system.

pancreas/ˈpaŋkrɪəs/Learn to pronouncenoun

1. a large gland behind the stomach which secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans, which secrete into the blood the hormones insulin and glucagon.

Your all class Wolf

Cheers George