Educate me -- why do we need a preamp?

Mystery

I do not have a preamp yet.
I've couple of HT receivers and stereo receivers.
For my purpose, they work fine.
For HT, I have my computer, DVD player and MP3 player hooked up.
For stereo, I have few inputs hooked up for music.
They all work fine and I never run out of headroom on volume.
Even a quarter volume is more than enough.

However, when I read others' good setups, I see preamp in all of them.
How does preamp help?
Is it just increasing input level so amp doesn't have to be cranked high for same volume?
How does preamp work for different sources such as portable players with low output level and CD player with higher volume output? Does the preamp automatically adjust level so amp always gets same level to prevent constant volume adjustments??? :question:
Thanks for clarifying.

bmbguy

If you have receivers, you don't have a need for a preamp because receivers have the preamp and power amp 'components' all in one package.

With separates, the preamp has the multiple source connections, does source switching and tone/volume control, while the power amplifier provides, well, power!

Mystery

Thanks for comment.
So for my current setup, there is no need of a preamp.
Will anything improve if I get a preamp?

polkfarmboy

I used to think that the preamp was the DAC but now there are so many DAC's that have volume control its seems just like its of no use

bmbguy

Mystery wrote: »

Thanks for comment.
So for my current setup, there is no need of a preamp.
Will anything improve if I get a preamp?

Most here will tell you that you will get better audio from quality separates than from most any 'receiver', and I don't doubt that is true. But I have not spent much time (or money!) exploring a great deal of gear, so I simply don't have the experience to offer any real opinion on the subject.

I'm sure others will have plenty to add -- those who have owned many of each!

Toolfan66

bmbguy wrote: »

Most here will tell you that you will get better audio from quality separates than from most any 'receiver', and I don't doubt that is true. But I have not spent much time (or money!) exploring a great deal of gear, so I simply don't have the experience to offer any real opinion on the subject.

I'm sure others will have plenty to add -- those who have owned many of each!

For HT a good receiver will do the job with a good amp IMO.

For a 2 Channel set up I would never use a receiver, separates are the only way to go IMO.

and let me add that if I only had the room to have one set up I would have my HT set up but I would still have a preamp with HT bypass and a quality DAC for when I listen to music.

Thanks God I have room for two set up's for I love my 2 channel rig.:cool:

mhardy6647

Two basic flavors of preamps - active and passive.

If one's power amplifier has enough gain, and one needs no contouring networks (e.g., an RIAA network to play LP records, or tone controls or some sort of analog EQ), a passive preamp can be a good choice. Typically, the only components are a volume control (attenuator) of some sort and an input source selector.

An active preamp adds (usually) a gain stage, and at minimum, an impedance buffer circuit between source and power amp. Active preamps typically also include source selection, sometimes include EQ such as tone controls, and might also include equalized additional gain stages for MM (or even LOMC) phono cartridges... in the olden days, they also frequently included a "head amp" and EQ network for the early commercial "tape decks" that had only the very low voltage output direct from the tape head.

I am currently using a simple passive preamp consisting of an autoformer volume control and a source selector. It is the silver box in the photo. It provides signal attenuation and connects multiple sources to my (slightly modified) "Simple 2A3" power amplifier.




Information on AVCs: http://www.intactaudio.com/

The JE Labs/Angela Labs Simple 45/ Simple 2A3: http://members.myactv.net/~je2a3/simple45.htm

Mystery

mhardy6647 wrote: »

An active preamp adds (usually) a gain stage, and at minimum, an impedance buffer circuit between source and power amp.

But the gain depends upon input source, correct?
For example, when I hook up my MP3 player, the volume knob in my receiver is at 11 O'clock but when I switch to CD player, I only need to turn the knob to 9 O'clock for the same amount of sound.
Does having active pre-amp adjust the input automatically?
I guess, I still have to adjust volume whether I have pre-amp or not.

mhardy6647

Nope, it will just provide additional gain if needed - this can be attenuated by the volume control. But, that said... some (actually quite a few) active preamps over the years contain "trimmer" potentiometers to normalize the volume levels of disparate sources to avoid the 'blasting' effect when changing from one source to another. A classic example (that I happen to have an example of and a photo of as well) is the McIntosh C-28. The black knobs on the top panel in the photo are (mostly) trimmers for the various inputs. There are some other gizmos and gadgets there, too.

I prefer the "less is more" approach to my active (and passive) electronics, personally. The C-28 isn't a great sounding preamp (even though it's still held in fairly high regard by the Mac fanboys). All the extra fluff in it certainly doesn't make it sound any better.



(trimmers are visible in a double row near the top of the photo)

tonyb

Basically put, a receiver is an all in one compromise. Tuner, pre amp, dac, processor, power amp, all in one neat little box. Take all those componants and stack them up seperately, and you'll wonder what compromises had to be made to get all that in one box. The biggest difference imho anyway is that seperates have their own power supply for each componant while a receiver shares one power supply for all.

steveinaz

A preamp is basically your systems control center, when you have seperate components. Providing connection from sources, volume control, signal routing, etc.

thsmith

In my case my HT and 2 channel are all in the same room. For me my preamp is a better front end than my AVR for 2 channel. So my AVR feeds my preamp for BRP and HD source. My TT and Music Server are connected to my PREAMP.

If you like what you got then your set. I would think a receiver would be better for music than AVR.

evhudsons

Toolfan66 wrote: »

For HT a good receiver will do the job with a good amp IMO.



and let me add that if I only had the room to have one set up I would have my HT set up but I would still have a preamp with HT bypass and a quality DAC for when I listen to music.

great idea, how would I do that? I have my HT in my living room which is where I am getting sloshed on barley and hops enjoying my SDA universe. My bedroom setup is mainly for the wife. I would love to switch back and forth between HT and 2 channel in one room. I have a local connection for a parasound 1500 preamp that would match the amp I'm using for the crs+. I'd love to figure out a way to incorporate that and share those speakers.

Mystery

Thanks for comments.
So I don't need a preamp right now.
I think they are a must have where amplifiers (instead of receivers) are used or for those who don't care to spend $$$$ to improve little sound quality. For a normal HT and music listening, receiver is good enough.