Pre-amp - how critical is it for sound quality, relative to power amp, for CD & DVD

[PENG]

.....the larger difference in sound quality happens at the pre-amp level anyway when you get into seperates, but why "wouldn't" a quality dedicated amplifier with build-quality geared to "ONLY" amplify, do a better job?.....

mtrycrafts:

mule is not the only one who claims the larger difference...at the pre-amp....., could you please phone your friend at Bryston (as opposed to google links ) and find out what the reason is, I am just curious. I am talking about CD & DVD line level stuff, I find it hard to believe the pre-amp would be as critical as the power amp that actually does the amplification.

With low level output phono cartridges, pre-amps actually amplify the signal and I have no problem seeing why they are so critical.

Thank you in advance.

 

[highfihoney]

count me in.

im with mule on this issue & i agree that the biggest differences are noticed with preamps when going from recievers to seperates.

im not sure that i'd equate "sound quality" with using stand alone preamps but i do equate differences in sound when comparing different stand alone preamps, these differences in sound have a direct impact on how a system will ultimately sound, this sound will be good to some & bad to others so im excluding quality as that is subject to each listener.

assuming that the speakers used are able to reproduce the different sonic traits of different preamps i place the level of importance with the preamp being 1st, then the amplifier, then the source being last.

i also think that hearing these differences is highly dependant on the speaker system being used,when i tried different preamps with my klipsch corner horns the differences between preamps were not so easy to hear,when i compared preamps using my line array speakers the differences are easily heard.

here are some examples of how different stand alone preamps sounded very different in my system with the line array speakers.

pass labs x1 solid state/ bloated bass, good midrange, extremely bright highs.

audio research ls9 solid state/ weak bass,over extended midrange, bright highs.

mcintosh c-100 solid state/ weak bass,great mids,smooth sounding highs.

mcintosh c-39 solid state/ strong clear bass,good mids,good but not perfect highs.

mcintosh c-2200 tube/ weak bass,perfect mids,great highs.

my all time personal favorite, marantz 2240 reciever (circa 1970's) used as a preamp in the same system, perfect bass, perfect mids,the best & cleanest highs ive ever heard.

disclaimer,these differences i heard in my system are not based on science nor am i recomending that anybody buy anything,i am only speaking of what i heard or what i "percieved to hear.

 

[Pyrrho]

mtrycrafts:

mule is not the only one who claims the larger difference...at the pre-amp....., could you please phone your friend at Bryston (as opposed to google links ) and find out what the reason is, I am just curious. I am talking about CD & DVD line level stuff, I find it hard to believe the pre-amp would be as critical as the power amp that actually does the amplification.

With low level output phono cartridges, pre-amps actually amplify the signal and I have no problem seeing why they are so critical.

Thank you in advance.

Assuming we are dealing with equipment that is well designed and not intended to alter the sound (an assumption that is false for many units), what is "most important" will depend on other things, such as the speakers used. If, for example, the speakers are a difficult impedance, then the power amplifier will be critically important, whereas with a speaker that is an easy load and reasonably efficient, the power amplifier will generally make little difference.

The main theory behind the idea that preamplifiers are more important to the sound than power amplifiers is that one is dealing with weaker signals, and therefore smaller imperfections will make a greater difference. Of course, at the input of the power amplifier, one is dealing with a preamp level signal, so the theory is not entirely satisfactory.

 

[Snarl]

Don't have the technical depth of some of the previous posters but from experience I can definitely attest to the value of a superior pre-Amp. My personal take on the situation has been that some receiver manufacturers have a greater degree of expertise in amplification and some in Pre-Amplification add the specialization of processing into the mix and things get exponentially more complex. I've had two integrated amplifiers, one in particular was a Yamaha AX592 that sounded a little harsh. I had the opportunity to Tap my Denon 3805 Pre-out into the Yamaha when experimenting with Bi-Amping and remote Zones and immediately noticed an improvement in sound quality. I suspect the Yamaha Amplifier in this case was excellent but the Denon appeared to have the superior Pre-Amp (Yes I experimented with tone/direct settings).

IMHO

 

[mtrycrafts]

mtrycrafts:

mule is not the only one who claims the larger difference...at the pre-amp....., could you please phone your friend at Bryston (as opposed to google links ) and find out what the reason is, I am just curious.

I'd love to call Chris Russell, chief designer, or anyone could. He is a great guy who will answer such calls He is up in Canada. But, this question is based in an assumption only, not in facts.

David Rich and Peter Aczel, 'Topological Analysis of Consumer Audio Electronics: Another Approach to Show that Modern Audio Electronics are Acoustically Transparent,' 99 AES Convention, 1995, Print #4053.

Rich covered preamps as well over the many years of his testing
His conclusions are different from mulster; Rich used DBT protocols

It is all about the human hearing thresholds. Good preamps are below those thresholds. I know some rather not read the spec sheets even if they are from 3rd party sources, but the devil is in there, if it has a devil to hide




I am talking about CD & DVD line level stuff, I find it hard to believe the pre-amp would be as critical as the power amp that actually does the amplification.


Very good belief, and you would win in a bet unless you are talking about a euphonic preamps. Easy to design one of those.

With low level output phono cartridges, pre-amps actually amplify the signal and I have no problem seeing why they are so critical.

Thank you in advance.

Yes, it would, and it does very well.
Folks in Toronto could also call Don Morrison that has preamps and audio. The Audio Critic reviewed his preamps a while ago. Impressive specs and so far below the thresholds, not even funny

 

[PENG]

mtrycrafts:
I'd love to call Chris Russell, chief designer, or anyone could. He is a great guy who will answer such calls He is up in Canada. But, this question is based in an assumption only, not in facts.

I know, but Bryston does make some fairly expensive preamps. Their BP26 for example is likely going to list for 3K or more, so I think Mr. Russell would likely defend its merit by telling us why preamp is a critical component for sound qualtity even for line level output sources such as CD and DVD players.

 

[mtrycrafts]

I know, but Bryston does make some fairly expensive preamps. Their BP26 for example is likely going to list for 3K or more, so I think Mr. Russell would likely defend its merit by telling us why preamp is a critical component for sound qualtity even for line level output sources such as CD and DVD players.

Well, his amps are not cheap either. The on line The Audio Critic reviewed their recent multichannel amp, 875HT, $5195. It shows the famous power cubed measurements for it. The TAC also did the Behringer A500 with its power cubed test and pictogram. The A500 is a bit better, certainly not worse, for $180.
Bryston has a 20yr warranty, not the A500. Etc. Not sure it can be defended but I haven't see anything from Bryston claiming anything special for their components beyond what they designed into them; that is in the specs.

That Don Morrison 2ch preamp, less than $1k, has specs at the thermal noise floors. Competent design with nothing mystical claimed but transparent.