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Preamp + power amp. Which one is more important?

Andiush

Active Member
Hi guys,
Can anyone explain me what is more important - preamp or power amp? For example, if I connect Yamaha preamp and Arcam power amp, what sound shall I get? Will it sound like Yamaha or Arcam (you can put any other brand names instead)?:confused:
 
D

Deleted member 781788

Guest
Difficult to say! but for my money I would say power amp.
However, I only have one source (my DAC) - so technically I do not need a pre-amp!
If you have a turntable, then the answer may be reversed.
What sources do you have?
That tells what the pre-amp is actually asked to do!
In my case (for example) a pre-amp is redundant.
 

BobBob21

Well-known Member
However, I only have one source (my DAC) - so technically I do not need a pre-amp!
Is it not more accurate, as per your signature, that your DAC is also a preamp but with the limit of only a two sets of analogue inputs?

Have to say I've always wondered the same as the OP and did wonder if I'd get a more "musical" experience simply by adding a stereo poweramp to my Onkyo AVR or by replacing it with an Arcam AVR with a longer term plan of adding a poweramp to that too (but will I maintain the Arcam sound if I got another brand of poweramp or not etc)
 
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Deleted member 39241

Guest
In my experience the pre-amp changes the tone and characteristics of the sound (eg bright / warm / harsh / soft) whereas adding more power makes the sound clearer and more expansive.

Having attempted to get good 2 channel sound from a variety of AVR's, I have found that just connecting my cd player directly to a power amp, sounds significantly better than going through any AVR. Connecting a power amp to the AVR pre-outs does improve the sound, if you already like it, and if you are adding more power than the AVR can provide on it's own in 2 channel mode. But the pre-amp in the AVR does still definitely affect things to a very large degree. Even when using pure direct mode.
 

Jampot90

Active Member
Which is more important - your left leg or your right?

Think rather in terms of matching the power amp to the speakers and the pre amp meeting your needs in respect of connectivity. Of course they need to be compatible with one another but that usually only amounts to matching the output of the pre to the input sensitivity of the power. In exceptional cases impedance plays a part but not likely to be an issue with most modern offerings.

Power amp and speakers and room interaction will have more influence in terms of how things sound and any variety of pre amps may change that - as Ken says, a cd with volume control is as simple as it gets and will likely reveal exactly how the power amp /speakers / room interact.

Unless it's all hidden away in a cupboard, the visual impact may be important too and (usually) same make stuff wins hands down.

Jim
 

BobBob21

Well-known Member
In my experience the pre-amp changes the tone and characteristics of the sound (eg bright / warm / harsh / soft) whereas adding more power makes the sound clearer and more expansive.

So power amps are just about power? In other words a £1,000 X branded one with 250w of power will sound the same as a £5,000 Y branded one with 250w of power?

Which is more important - your left leg or your right?
Right, I've a doctors letter to prove it too :)
 
D

Deleted member 39241

Guest
So power amps are just about power? In other words a £1,000 X branded one with 250w of power will sound the same as a £5,000 Y branded one with 250w of power?

Very possibly!

This is an interesting read, if you've not seen it already:

Matrix HiFi --> Blind testing high end full equipments

I actually bought a Behringer A500 after reading this last year, because Amazon had stock and it was extremely inexpensive (plus sale or return option) and I was curious. I did an A B test with my CD player going through a Cambridge Audio CXR 200 (£2k AVR) and then going through the Behringer (£150 PA), same speakers, Kef Q700, same cables, same room. The Behringer sounded better.
 
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Deleted member 781788

Guest
Is it not more accurate, as per your signature, that your DAC is also a preamp but with the limit of only a two sets of analogue inputs?

Have to say I've always wondered the same as the OP and did wonder if I'd get a more "musical" experience simply by adding a stereo poweramp to my Onkyo AVR or by replacing it with an Arcam AVR with a longer term plan of adding a poweramp to that too (but will I maintain the Arcam sound if I got another brand of poweramp or not etc)
My Dac may have more inputs, but I do not use them, All I need is a volume control!
I do have a 15W tube power amp at work, which I installed a stepped resistor bank volume control to, connected to DAC and that will do me.
My point was that, with one line-level input - provided you have a volume control - one does not need a pre-amp.
But a turntable does need an RIAA cartridge preamp, that does introduce its own sonic characteristic.
Otherwise line-level preamps do not serve any purpose - they can be replaced by a passive volume control in most cases.
and as turntables have become less popular these days, preamps are becoming more redundant.
AV receivers are a different kettle of fish altogether.
They do serve as DAC too, connected to a multi poweramp section.
But since this is a HiFi forum, I do not want to discuss Audio video issues.
 

BobBob21

Well-known Member
Ok, to flip the question around then..... what is the definition of a preamp?

When does something that takes an input from a/multiple source(s), has a volume control and then passes it to a power amp become a "pre amp" and when is it something else?
 
D

Deleted member 781788

Guest
Ok, to flip the question around then..... what is the definition of a preamp?

When does something that takes an input from a/multiple source(s), has a volume control and then passes it to a power amp become a "pre amp" and when is it something else?
I suppose when it does amplify or process the signal!
Or call it when it can not be replaced with passive circuitry .
Switching inputs, or attenuating the signal level can be achieved by un-powered (almost) inert passive components.
A switch box and volume control, is a control unit.
Preamplifier - Wikipedia
Misnomers[edit]
In a home audio system, the term 'preamplifier' may sometimes be used to describe equipment which merely switches between different line level sources and applies a volume control, so that no actual pre-amplification may be involved.
 
Last edited by a moderator:

Ugg10

Distinguished Member
Punctilio - interesting observation but i would argue that these two amps share the same space in terms of price per amp. The Beringer is approx £200 for two channels (£100 per channel) and the Cambridge is £2000 but the Cambridge is a 7.1 amp and has a second zone and bi-amp capability so say 9 amps. So when you add the pre-amp, decoding circuits and software licenses the Cambridge is not far off £250 per channel. Which is more than the Behringer but not the order of magnitude it seems on the face of it £200 vs £2000. Less circuits and processing in the signal path obviuosly helps make the stereo designs system work well compared to the AV receiver.

Ken T - got to agree that if you have only a couple of sources then and one is digital then a Dac with a volume control is all that is needed. I have a Fostex A3 fed by my PC through USB and feeding a pair of Rotel Power Amps - works well for me. The Beresford 7510/7520/Cayman is also in the same category as well as the more expensive Audiolab M-Dac and the Dacmagic Plus.
 
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Deleted member 39241

Guest
Punctilio - interesting observation but i would argue that these two amps share the same space in terms of price per amp. The Beringer is approx £200 for two channels (£100 per channel) and the Cambridge is £2000 but the Cambridge is a 7.1 amp and has a second zone and bi-amp capability so say 9 amps. So when you add the pre-amp, decoding circuits and software licenses the Cambridge is not far off £250 per channel. Which is more than the Behringer but not the order of magnitude it seems on the face of it £200 vs £2000. Less circuits and processing in the signal path obviuosly helps make the stereo designs system work well compared to the AV receiver.

Fair point! I actually paid £130 for the Behringer last year, looks like the price has gone up since then. The Cambridge only has 7 amp channels, so if you bi-amp or use zone 2 you can only run 5 speakers in the main zone, but you are right, it has a whole load of other features incorporated into it, whereas the Behringer is a pure power amp.
 

BlueWizard

Distinguished Member
Hi guys,
Can anyone explain me what is more important - preamp or power amp? For example, if I connect Yamaha preamp and Arcam power amp, what sound shall I get? Will it sound like Yamaha or Arcam (you can put any other brand names instead)?:confused:

It depends on what you mean by important. You really have to have both. If you mean important to the sound quality, that is also difficult to answer. It would depend on which Yamaha Pre-Amp and which Arcam Power Amp. As to which sound you will get, likely it will be a blend. As to which sound will dominate, meaning be more noticeable than the other, again, difficult to determine.

Can you be more specific about why you are asking this question? Perhaps more context would help us come up with better answers.

I would say generally, the quality of the sound is related to the quality of the equipment you buy. Price may not be a guarantee of quality but it is a good indicator.

Generally there are a limited number of Pre-Amps to choose from and they all tend to be on the expensive side relative to getting an Integrated Amp. Equally Power Amps tend to be expensive relative to getting an Integrated Amp. So, if you want the best value, get an Integrated Amp.

As to how important a Pre-Amp is in general, it depends on what you have to connect to it. If you have a Turntable, CD, Network Streaming, BluRay, DAC,... you are going to need a Pre-Amp with lots of inputs. However, if as Ken T said, you have one and only one source component, then a single volume control could be enough.

Then we get down to what constitutes a Pre-Amp. They do make purely passive pre-amp, so in that sense, a simply passive volume control could technically count as a Pre-Amp.

The real question is - What do you need to do? That is, what do you need to accomplish? Buy equipment that you like that you can afford, that do the job that you need done, and you should be fine.

As to AV Receivers, keep in mind that most AV Receiver convert the Analog Inputs to a digital signal so they can process it, then convert it back to Analog again. Some people object to that unnecessary level of processing. Though I think you can over-ride that conversion if you select Pure Direct Mode. That should bypass the additional A/D-D/A conversion.

So going back to the beginning - Why are you asking this question? What is happening in you Audio Life that prompted this curiosity?

Using a Car as an analogy, what is more important, the engine or the wheels? The reality is, the car is worthless without both. Same with Audio, you need both to make the system work. But, as has been indicated, the degree to which you need both varieties depending on your personal needs. Ken T gets by with a simply Volume Control. Myself, I like having Tone Controls though I rarely use them. I like having a DAC built into my Pre-Amp, it is the most economical choice. I like having Pre-Amp Outputs on my Integrated Amp. I would much rather have Pre-Amp out than have a Sub Out. The Pre-Amp out can drive a Subwoofer, but a Sub Out can not drive a Stereo Amp.

So, it is not about one absolute right choice, it is about the choice that best suits your personal needs.

As to what you should get in a Pre-Amp/Power-Amp combo, that's down to your personal requirements and the budget you have available. You do the best you can with what you've got. Few of us can get the best, the best we can do is really just the best we can do.

Steve/bluewizard.
 

BioPaul

Novice Member
To answer the question directly, the preamp is far more important than the amp from the point of view of sound quality. The preamp delivers a signal to the amp to amplify. The higher the quality the preamp the higher the quality the signal the amp has to work with to deliver to the speakers.
I am surprised by the poor, indirect and muddled answers to this simple sound question in this forum.
 

dannnielll

Well-known Member
Hi Biopaul, I am not sure the previous answers were muddied... And whether your answer clarified anything. There is confusion as to what constitutes amplification.
It was clearer in the bad old days of vinyl and pickups. The signal was typically only a few millivolts in amplitude,and capable of microamps of current from a pickup. The primary task of the preamp was to increase the voltage by nearly a thousand fold and to compensate for a deliberate frequency curved response from the recording studio. The preamp also provided tone controls . It also provided for switching in alternative signal sources from tape recorders and later CD players. However the signals from these other sources are typically provided at 1 volt amplitude,so the voltage gain function the preamp is bypassed.
The power amplifier section , provides only modest voltage gain , perhaps only a factor of 20 to 40 , but is capable of driving large currents perhaps 5 or more Amps into speakers.
 

BlueWizard

Distinguished Member
To answer the question directly, the preamp is far more important than the amp from the point of view of sound quality. The preamp delivers a signal to the amp to amplify. The higher the quality the preamp the higher the quality the signal the amp has to work with to deliver to the speakers.
I am surprised by the poor, indirect and muddled answers to this simple sound question in this forum.
The pre-amp is only the most important if it does what you need done. The best in the world falls short if it doesn't meet that goal. First you must know what you need before you can get what you want.

In short neither is most important, meeting your goals and budget is the objective. It can't be reduced to one item over another, it has to be driven be specific needs and budget, and has to be a system approach.

Though I'm not necessarily disputing the point you made.
Steve/bluewizard
 

Paul7777x

Distinguished Member
The power amp has to have at least enough power and current reserve to handle any combination of low impedance busy music signal that that the speaker and source will put it through.

And, obviously, that means without discernible alteration of the signal.

Once that’s achieved then the better quality (most transparent to the source signal) the pre/dac is, the better for those in this hobby or, in many cases, lifestyle.

Neither are as important as the room or the speakers.
 

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