preamp vs amp: relative effect on sound?

Q1.. I was always of the belief that pre amps had the biggest impact regarding sound that changed after i bought the AGD amps. But in most cases i would say it's 60/40 with pre's having the biggest impact.

Q2.. Higher gain pre's can deliver more dynamics and detail.

@twoleftears

it is highly situation specific, as you can imagine

prentice is correct, preamp will have more influence if the amp has a pretty easy time gripping and driving the speakers, otherwise, amp to speaker interface and interaction can be dominant

for many years i have always felt the heart of my system is my conrad johnson linestage (prem 16ls2 or et5 or art over the years), but i used fairly easy to drive bbc heritage speakers like spendor harbeth proac quad -- and i use plenty of amp to drive them whether tube or ss -- thus the cj brought the magic to the party...

My "fun" system which I use for music and HT purposes consisted of Wharfedale Opus-3, Krell KRC-3 and Adcom 5802. My preamp is nearly twice the price of my power amp, but I think it is the best way to bring out the sound quality of my system. I swap out the Adcom for a Mark levinson 23.5 and only observe about 5-10% improvement. So, I could almost certainly say that the preamp makes more impact on my overall sound quality comparing to the power amp. How much more impact? I really don’t know.

There are too many variables. You can't lump all solid state in the same basket; some are harsh and bright no matter what you do. The brightness and harshness is the result of distortion; the ear assigns a tonality to all forms of distortion. In the case of solid state, the distortion is higher ordered harmonics which the ear uses to sense sound pressure so its keenly sensitive to their presence, even though on paper they appear to be 'negligible'. They are not.


If the amp is able to employ enough feedback and for the record most are not, it will be able to get rid of most of that annoying distortion. But 99% of solid state amps out there have this problem.


Solid state preamps often have this problem as well. Again in a nutshell, if the circuitry in the preamp is discreet, its likely that it will not have enough feedback to control the higher ordered harmonics and so will also sound bright even though its distortion on paper is quite low.

So if you're going to involve tubes to get around this problem you'll want to use a tube preamp, since the brightness of a solid state preamp can be reproduced by any good tube power amp.


There are solid state preamps that are based on opamps. These have the possibility of not being bright if properly designed (i.e. not asking too much gain out of the opamps; 20dB is about the upper limit with most opamps; this leaves enough gain bandwidth product to prevent distortion from causing brightness). If you have a preamp like this then a tube power amp could be used, or a solid state for that matter.

One tip: most amps sound decent at low volumes. Its when you crank it up that the brightness (if its there) becomes unpleasant! The mark of a good system is that it remains relaxed at high volumes such that you can't tell how loud its playing. IOW if it sounds loud that's bad- move on.

In theory, preamp should have bigger impact on the sound. However, in reality, no matter how good your source and preamp are, you will not get good sound until the amp driving the speaker with ease.

The biggest impact of the system is speaker. AND speakers have to match with amp.