[Jlee80]

I see preamps around the forum, but what are preamplifiers used for? Do people generally use it with their headphone set-up or mainly speakers? Would I benefit from a preamplifier in my set-up? I have foobar2000 -> Chaintech AV710 -> Entech Number Cruncher 203.2 -> Headamp Gilmore Lite -> HD650. I am looking into bookshelf monitors right now, and may get a Beta22.

 

[vcoheda]

i can't imagine someone using a preamp in a headphone only set up.

 

[Kees]

No use for a preamp in a headphone setup.

 

[LoweArt]

Pre-amps are used inconjunction with power amps.

Some headphone amps are able to be used as pre-amps which
would suit people wanting to use this same rig to feed to a power amp
and hence a stereo hi fi speaker setup.

If you are just wanting to power/drive headphones, there is no
advantage in adding a pre-amp into the equation.

On a side note, I just sold my old pre-amp and bought the latest model for
my stereo Hi Fi rig -> http://www.audioresearch.com/LS26.html

My wallet hurts !

 

[Jlee80]

So preamps are mainly used to connect to another power amplifier and then to speakers? What is the use? Why doesn't a person just connect the speakers directly to the power amp to the receiver or DAC?

 

[Alpha 904]

As far as I can tell, preamps are used to give a bit more juice to the signal before reaching the power amp. the most common type of preamp is a vinyl preamp used for record players. I've tried using a record player directly with a stereo receiver and it sounded rather thin. A vinyl preamp is especially necessary if you have a headphone setup.

 

[KrooLism]

Quote:

Originally Posted by Jlee80 /img/forum/go_quote.gif So preamps are mainly used to connect to another power amplifier and then to speakers? What is the use? Why doesn't a person just connect the speakers directly to the power amp to the receiver or DAC?

Your power amp should only have one input and one set of outputs for speakers.

So how would you control the volume?
You also have CD player, DVD player, Turntable, Laptop and Set-Top Box you wish to play though the speakers.
Sure, you can plug and unplug cables all the time... but who on earth would want to do that?
What if you had two power amps and sets of speakers and only one source...??

That's where your pre-amp comes into play.
I have a Grace Design M902 headphone amp / dac.
1 - I have PC going into the S/Pdif input
2 - I have CD player going into the RCA inputs
3 - I have a laptop going into the USB input
4 - I have a turntable going into the Balanced inputs.
5 - I have DVD going into the optical input.

For the outputs
I can control two headphones at once... AND a set of speakers using the RCA outputs independent of the headphones.

It basically ties all my audio sources and equipment into one.

 

[LoweArt]

Quote:

Originally Posted by Jlee80 /img/forum/go_quote.gif So preamps are mainly used to connect to another power amplifier and then to speakers? What is the use? Why doesn't a person just connect the speakers directly to the power amp to the receiver or DAC?

Most ( not all ) power amps don't have the correct input impedance to accept the signal purely from the source equipment like a CD, DVD or DAC to be able to amplify it correctly out to the connected speakers. That aside, the majority of power amps ( not integrated amplifiers ) don't have any volume control what so ever so even if you connected your source component straight into a power amp, how are you going to control the volume ????????? Pre-amps not only provides and conditions the source equipment's signal for delivery into a power amp, it serves as volume and or balance control as well as multiple input selector/control.

Here's the setup ->

Source Component ( CD player ) -> Preamplifier -> Power Amp -> speakers

or how most people have it ->

Source Component ( CD player ) -> Integrated Amplifier -> speakers

Still confused, I use 2 solid state power amps ( bi -amped ) one that powers the mids/bass and one that does the highs and all is controlled by a tube pre-amp !

 

[Dept_of_Alchemy]

Impedance matching, whatever that means. Phono pre-amps apply a RIAA curve to modify the signal and it's necessary for vinyl to sound correct (funny how nobody even mention this degrading sound quality of vinyl rigs).

 

[KrooLism]

Quote:

Originally Posted by Dept_of_Alchemy /img/forum/go_quote.gif Impedance matching, whatever that means. Phono pre-amps apply a RIAA curve to modify the signal and it's necessary for vinyl to sound correct (funny how nobody even mention this degrading sound quality of vinyl rigs).

Agreed.

I've recently had the pleasure of sampling Meridian's top end products and I truly believe that the future of recorded music is digital.

Come on Sony and Philips - the 99.9999999% of the iBud population will never pay you money for SACD or DVD-A technology... might as well release it for free so recording companies can start making hybrids!!!

 

[LoweArt]

Quote:

Originally Posted by Dept_of_Alchemy /img/forum/go_quote.gif Phono pre-amps apply a RIAA curve to modify the signal and it's necessary for vinyl to sound correct (funny how nobody even mention this degrading sound quality of vinyl rigs).

Correct ! That's what phono pre-amps are for because the signal supplied straight from a stylus ( regardless of whether it's MM or MC ) is not enough or correct to be fed into an integrated amp's or pre-amp's inputs.

I'm a bit puzzled by the comment of "funny how nobody even mention this degrading sound quality of vinyl rigs" I have about 60 vinyl LPs of which I bought because the CD versions were not up to standard ( very bad transfers to digital or bad mastering ). I even have one of Norah Jones' albums on LP and no one that comes over for a listen on my stereo rig could pick up that it was an LP and not a CD playing until I told them.

 

[onvn]

Preamps amplify weak signals to line-level..? That's wiki-knowledge for you!

 

[tot]

Preamps do not amplify anything, they are mostly for source selection and volume control. Line level signal is typically around 2V max and for power amp that means maximum volume.

There are also passive preamps which do not have any electronics at all, the volume just passive attenuation.

If your source has volume control and you have no need for source selection after that (like some DACs or CDPs), you could hook poweramps straight to them. Less electronics in the signal path.

 

[Agnostic]

Quote:

Originally Posted by Jlee80 /img/forum/go_quote.gif I see preamps around the forum, but what are preamplifiers used for? Do people generally use it with their headphone set-up or mainly speakers? Would I benefit from a preamplifier in my set-up? I have foobar2000 -> Chaintech AV710 -> Entech Number Cruncher 203.2 -> Headamp Gilmore Lite -> HD650. I am looking into bookshelf monitors right now, and may get a Beta22.

If you need a nice cheap amp for those bookshelves have a look at the Sonic Impact T-amp. Looks like ugly plastic but sounds great. Needs efficient speakers to sound it's best though.

 

[Contrastique]

Sorry to hop in on this one but I might be considering a Rudistor RPX33 in the (far) future. Would it make a differ or would it be even meaningful if I use it as a preamp in my home-rig? I have a Akai Digital Integrated Amp AM 69.
Or is it only meaningfull if attached to a poweramp? And if so what would be the benefit of such set-up compared to an integrated amp set-up except for the more connections possibility?
Maybe dumb questions but I am new to this.