shinobi
New member
i decided to put this up because many bassists seem to be confused over the terminology, whereas this might not be so where guitarists are concerned. this is probably because many manufacturers combine preamps with DIs.
this is written using my own knowledge and experience, so it's by no means perfect. constructive input is welcome.
i'll try to use simple explanations without compromising too much on the accuracy of description.
1. etymology & description
preamp - preamplifier
D.I. - direct injection
from wikipedia:
http://en.wikipedia.org/wiki/Preamplifier
2. preamp
amps comprise of 2 main sections - preamp + power amp
at the preamp stage you will have your input gain and EQ. this prepares the signal for the power amp, which will amplify the signal to 100W, 200W, 500W and so on. input gain is an active boost that might be called 'pre-gain', etc. after the power amp there is usually a passive cut that can be called 'post-gain', 'volume', etc. this, however, varies depending of the specifications of the amp.
most players, especially newer players, will be more familiar with combo amps. as the name suggests, it is a 'combo' of preamp, power amp and speaker cabinet.
perhaps i or someone else could make an amp FAQ as well.
there are 2 ways of looking at pedal preamps;
1. they perform essentially the same function as a pre-amp unit, in a pedal.
2. they perform essentially the same function as the preamp of an active bass (i.e. the electronic components of an active bass), in a pedal.
depending on the specs of the pedal, it could provide some EQ control, sometimes gain, sometimes drive, usually a buffer.
3. DI
a DI basically prepares the signal from your instrument for a mic-level input, such as a mixing console.
conventionally, DIs are more popular among bassists than guitarists because bassists usually play clean. hence they do not lose out much or may even benefit by going directly into the mixer.
on the other hand, it is common among guitarists to drive tube amps to the point that the signal clips. this is what you call overdrive or distortion. hence the type of amp and cab use factor heavily in their tone. as such, it is common for guitarists to use an amp+cab combination, which then goes into the mixer by placing a mic in front of the cab.
of course, in the modern day, effects are very common among bassists, due to experimentation and creative implementations in music today.
4. relationship between preamp & DI
as explained earlier, it was conventionally thought that bassists prefer a clean signal. this could be one explanation why DI is more common among bassists than guitarists.
the problem with DI is that since no amp is involved, the player has significantly less control over his tone.
manufacturers realised this and hence combined preamps with DIs.
5. examples
DIs :
Boss DI-1
preamps without DI:
Aguilar DB924
Xotic Bass BB Preamp
Sansamp Character Series
onboard preamps:
John East J-Retro
ACG
Audere
Aguilar OBP
preamp + DI:
Sadowsky Outboard Bass Preamp/DI
Sansamp Bass DI
Seymour Duncan Paranormal
MXR M-80 bass di+
this is written using my own knowledge and experience, so it's by no means perfect. constructive input is welcome.
i'll try to use simple explanations without compromising too much on the accuracy of description.
Contents
1. etymology & description
2. preamp
3. DI
4. the relationship between preamp & DI
5. examples
1. etymology & description
2. preamp
3. DI
4. the relationship between preamp & DI
5. examples
1. etymology & description
preamp - preamplifier
D.I. - direct injection
from wikipedia:
http://en.wikipedia.org/wiki/Preamplifier
http://en.wikipedia.org/wiki/DI_unit
most preamp pedals for bass do pretty much the same thing as the preamp of an amp.
2. preamp
amps comprise of 2 main sections - preamp + power amp
at the preamp stage you will have your input gain and EQ. this prepares the signal for the power amp, which will amplify the signal to 100W, 200W, 500W and so on. input gain is an active boost that might be called 'pre-gain', etc. after the power amp there is usually a passive cut that can be called 'post-gain', 'volume', etc. this, however, varies depending of the specifications of the amp.
most players, especially newer players, will be more familiar with combo amps. as the name suggests, it is a 'combo' of preamp, power amp and speaker cabinet.
perhaps i or someone else could make an amp FAQ as well.
there are 2 ways of looking at pedal preamps;
1. they perform essentially the same function as a pre-amp unit, in a pedal.
2. they perform essentially the same function as the preamp of an active bass (i.e. the electronic components of an active bass), in a pedal.
depending on the specs of the pedal, it could provide some EQ control, sometimes gain, sometimes drive, usually a buffer.
3. DI
a DI basically prepares the signal from your instrument for a mic-level input, such as a mixing console.
conventionally, DIs are more popular among bassists than guitarists because bassists usually play clean. hence they do not lose out much or may even benefit by going directly into the mixer.
on the other hand, it is common among guitarists to drive tube amps to the point that the signal clips. this is what you call overdrive or distortion. hence the type of amp and cab use factor heavily in their tone. as such, it is common for guitarists to use an amp+cab combination, which then goes into the mixer by placing a mic in front of the cab.
of course, in the modern day, effects are very common among bassists, due to experimentation and creative implementations in music today.
4. relationship between preamp & DI
as explained earlier, it was conventionally thought that bassists prefer a clean signal. this could be one explanation why DI is more common among bassists than guitarists.
the problem with DI is that since no amp is involved, the player has significantly less control over his tone.
manufacturers realised this and hence combined preamps with DIs.
5. examples
DIs :
Boss DI-1
preamps without DI:
Aguilar DB924
Xotic Bass BB Preamp
Sansamp Character Series
onboard preamps:
John East J-Retro
ACG
Audere
Aguilar OBP
preamp + DI:
Sadowsky Outboard Bass Preamp/DI
Sansamp Bass DI
Seymour Duncan Paranormal
MXR M-80 bass di+
