Preamp

[gareththegeek]

I am using an M-Audio Delta 44 on Xubuntu 8.04 with the Ubuntu Studio packages and I am loving it!

I have one question which is not really linux related but..

People always say you need a preamp to bring a guitar up to line-level for recording but it has always been my experience that electric guitars are always too loud when connected directly to a sound card and must be turned down.

Can anyone explain this to me, why use a preamp?

Cheers!

[AutoStatic]

Hello gareththegeek, I'm not familiar with the M-Audio Delta 44, I have an Edirol UA-25 myself. All I know is that I need the pre-amp switched on otherwise the signal is both dull sounding and not loud enough.
It also depends on what kind of pick-ups you're using. Single coils have a lower output than humbuckers. When I plug in a guitar with humbuckers I have to turn the volume down indeed, but the guitar still sounds better with the pre-amp switched on.

[mcduck]

There's a bit more to the difference between line level and the signal coming from instrument pickups & microphones (or headphone & speaker signal levels).

It's not just a question of voltage ("signal loudness"), but also includes stuff like output impedance and nominal signal level. Even while the loudness of the sound signal might be OK when using wrong connection, the quality of the sound will suffer.

So if you want to get good sound quality, you need to use a pre-amp to handle the conversion to line level, even though the sound might be loud enough (or even too loud) without a pre-amp.

[eric71]

Not a preamp but a DI Box may be what you are thinking of.

http://en.wikipedia.org/wiki/DI_unit

I just got a used Behringer Ultra G from a friend and I can finally record my guitar directly with its volume turned up properly.

http://www.behringer.de/EN/Products/GI100.aspx

[gareththegeek]

Actually I was wrong before when I said I had to turn the guitar down. I have to turn my split coil bass down but my humbucker guitar isn't loud enough. I solved the problem by connecting to one of these http://www.wavesgtr.com/html/product_igtr.html

Since this takes the signal from instrument to headphone levels.

Is this as good as using a preamp or di, would I hear the difference if I shelled out for one?

Cheers for the replies!

[AutoStatic]

I own a Line6 PocketPod which is a similar device. It's not really a DI or a preamp so if you want to record just your guitar and process it further on your PC then I'd look for a seperate preamp (http://www.thomann.de/gb/art_tube_mp.htm) or a decent soundcard with good preamps (http://www.thomann.de/gb/cakewalk_ua_25_ex_cw.htm).

[gareththegeek]

So to summarise, ideally I should use a preamp to provide impedance matching for optimum efficiency of power transfer (giving less noise) but my method will be fine for now until I have some spare cash!

Thanks for all replies!