Why Do We Use Preamps?

A preamp serves five functions:
control volume
select inputs
provide any needed gain
buffer volume control from output cable

and the least understood (but nevertheless very real):
control the interconnect cable, i.e. prevent the cable from having an effect on the sound of the system.

PVCs have no buffering or cable control, so as you decrease the volume you will find impact and bass diminished. TVCs can do the job properly if designed correctly.

Active line stages can too, although IMO too many designers fail to understand the fifth point above. If an active line stage is properly designed and built, however, it will be more transparent than the cable it is driving. So if you experience it the other 'way round, guess what?

because most people can't afford a 15,000.00 memory player !

This thread is perfect timing for me. I was having issues with my Esoteric X03 SE into my preamp on certain CD's - I had dismissed it as poor recordings until my $69 Esoteric SACD (disc) sounded BAD, so I investigated. I bypased my preamp and the sound was UNBELIEVABLE. I was listening for hours. Totally taken in by the musical experience - not the sound. I was playing entire CD's, which I hadn't done for years. I listened for 10 hours the first day. I did some research and found that there was a known, albeit infrequent issue, with my preamp. Decided to audition an ARC LS26 active preamp (hasn't come in yet) but could not believe adding something between the CD player and amp (actually active crossover w/volume control) would sound better. I researched passive preamps and was prepared to audition one (either Bent Audio or Music First--I do need balanced and SE inputs-a few of them). So, before going the passive route, I decided to bypass the preamp for my turntable/phonostage. Figuring if the preamp doesn't drive the crossover, a passive won't cut it. When I placed the needle in the groove, I heard some pretty good sounds (clean, black, detailed but not sure if better or worse than with the preamp). I just finished listening with the preamp back in the line. Just as quiet, detailed and black but with PRAT, and better soundstaging. The PRAT was missing without the preamp. Just a better presentation, slam, dynamics - sounded pretty darn good. So, I don't think I will be changing preamps either to an active, or passive. I will just switch cables when I want to go from the Esoteric to my preamp. So, I am sure system synergy is key but in my system, my preamp degrades the CD sound but does make the phonostage sound great. I also tried my Benchmark DAC direct bypasing the pre and wasn't happy with it. Much better with the preamp. Saves me $6,000 for a new preamp, and less convenient but I am very thrilled with the sound I am getting from all sources.

Ryan, no offense intended or taken.

A pre amp and a tube buffer are separate animals with different purposes.
In my experience an active tube/ss pre amp is a must for a complete system.
Dayzee chain 2 or 3 pre amps together,what kinda drugs you on?

So if the goal is to add more depth and clarity to the sound, would it then serve almost the same purpose as a tube buffer, or maybe even a separate full-sized amp with gain control that you use further up the chain? Could you daisy-chain 2 or 3 pre-amps together?

Thanks Theo for posting a thoughtful response. No offense, Unsound.

Ryan

I have gone both the passive and the active route. In theory, your are correct that a passive should give greater purity and transparency. And I do hear that with a passive, but I also think it comes at a cost.

The music loses some oomph, weight, drive and robustness. It can get bleached and thin and somewhat threadbare compared to an active. Personally, I prefer active cause I think it makes the music sound more real and alive.

And please don't say I got these results because I did the passive thing wrong. I followed all the rules: short low capacitance IC, impedance matching, amp highly sensitive on the input, gutsy source output, etc.

Others may hear differently and prefer differently. I'm sure anyone can hear the active vs. passive differences. Then it just comes down to subjective preference. Just use your own ears and decide for yourself.

In my opinion the advantages to a seperate pre-amp vs. intergrated or receiver is, better quality of sound.
This is acheived by seperate power supplies doing one task.
In a receiver or intergrated you would have a power supply
powering amplifier section along with the pre amp. And in a receiver the tuner or processing circuitry. All these various items can produce their own noise and infect the sound path. Regardless of how much the manufacture isolates the different circuitry I think it is impossible to completely isolate within a single box using a single power supply. The other reason that I like the seperates is that I can mix and match with different brands, models, SS/Tube etc. I provides much more flexability to any system. In my case I use Audio Research Tube pre amp with McIntosh SS amps. I can use my Pre-Pro by utilizing the unity gain in the pre amp. This virtually gives me one system that is two, one HT and 2 channel. I guess another example can be the use of CD transport with a DAC vs. single box CDPs. I don't use a seperate dac with mine but it has advantages that some prefer. Again a good transport can sound quite differently with various DACs. So one can tailor the sound to please his/her ears. We are all different and the more flexabilty we have in a system the better the odds of conquest in our search for the Audio Grail. These are all of course my opinions and other may add to or disagree. One last note is, that I wrote this today and it is not in the archives..yet. Sometimes the same question gets asked but different answers pop in as not everyone reads each thread. The beauty of these forums is there are no rules against asking.

1. to match impedances between source and power amplifier
2. to control the volume between source and power amplifier

Please check the archives.