preamp vs amp: relative effect on sound?


Recently, there was an interesting thread on combining a tube preamp with a SS amp, which is what apparently a lot of people do.

So two questions.

Q1: in a preamp + amp combo, does each unit affect the eventual sound equally, 50/50, or is one going to affect the sound more than the other?

Q2: in a combo of higher gain preamp + lower gain amp, will more gain being provided by the preamp have any effect on your answer to Q1?
C943649e 64b4 48a7 a173 3590ba214727twoleftears
60/40 sounds right.
The preamp is further up the signal path and therefore has a greater influence. So, while the right answer is always it depends because it is a system and components are different. But say maybe 65 / 35 pre / amp for thinking about it. But if you have an underpowered amp then upgrading this will have a disproportionate difference, as an example.

Q2.. All the components I have bought have not varied enough that it has influences Q1. In most cases the gain on the preamp normally been roughly the same as I swapped them. I remember some big differences in the  40 to 50 years ago timeframe. 

 

Anybody else?

How about Q2?
Depending on your speakers, the amp could be as much as 80%.

For q2, it’s more about the the voltage required for full output on your amp. For example, if your amp requires .5 v for full rated power, you would probably want to pair it with a low gain preamp.

Also, the input impedance of the preamp should be at least 100 times higher than the output impedance of your preamp as a general rule of thumb.
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.
This sort of reductionist questions are useless, but they just keep coming. The audio system is what the word says: a system and a complex one. With a bit of imagination you could even draw a comparison with system theory in physics. When the audio set is stable (as in 'well balanced') the change of individual components will have less of an impact. When the system is unstable even a cable swap may throw things out of whack. Then every change will likely trigger another in a whole string of 'upgrades' until there's a new found balance, a new 'order out of chaos'. If you're lucky. 

@atmasphere Most designers of solid state amplifiers seem to strive for minimal or even zero feedback. Feedback is treated as a negative, something that should be avoided at all cost. Your remark seems to suggest sufficient amounts of feedback are required to reduce distortion. Then why would most solid state designers try to avoid it?



Most designers of solid state amplifiers seem to strive for minimal or even zero feedback. Feedback is treated as a negative, something that should be avoided at all cost. Your remark seems to suggest sufficient amounts of feedback are required to reduce distortion. Then why would most solid state designers try to avoid it?
@edgewear  They don't. Solid state amps that eschew feedback are quite rare!
they both have an equal effect but an amp or preamp with distinctive characteristics will dominate.  
In my experience the preamp has an incredible sound impact.

I upgraded from an integrated amp to preamp and amp in two steps.

I first bought a tube preamp (McIntosh C 2600) and it took over the preamp duties from my NAD C375BEE. I was shocked on the impact.

I was able to 'audition' it at home and the improvement in preamp was audible using tape deck, turntable, streamer and burned CDs.(tube preamp has phono stage and DAC built in).  

I then bought a MC 302 McIntosh amp and it was an improvement but I the preamp was the reason the journey was accelerated.  I think its about 65/35 split.  

I can't answer Q2.