What does a bass 'preamp' do?

Your weapon of choice
Post Reply
User avatar
Mr Bass Man
Silver Member
Posts: 238
Joined: Sun Jun 17, 2012 3:10 pm
Bands / Groups: splt-second top Auckland covers band
Location: North Shore, Auckland
Contact:

What does a bass 'preamp' do?

Post by Mr Bass Man » Wed Feb 27, 2013 8:13 pm

This is probably a dumb blonde question and after playing bass for over 20 years I should know the answer, but what does a separate 'preamp' do?
I've seen bass amp heads that have preamp in / out inputs (don't think my warwick Profet 5.1 does though) and I've seen a cheap Jansen 'preamp' for sale on TM - but what does the preamp actually do? does it give you more control over the sound / tone of your amp, or does it lift the volume, meaning you don't have to turn your main amp volume up too much on stage?

Just something I've always wanted to know!
"We became rich a lot later than I thought - now I'm too old to enjoy my money" - John 'Thunderfingers' Entwhistle

DubnBass
Bronze Member
Posts: 41
Joined: Sat Sep 25, 2010 10:51 am
Bands / Groups: One Waka
Location: Chch

Re: What does a bass 'preamp' do?

Post by DubnBass » Wed Feb 27, 2013 11:31 pm

An onboard preamp is effectively an equalizer that allows you to boost or cut frequencies (commonly Bass/Mid/Treble or Bass/Treble). In most cases, basses with onboard preamps have a 'hotter' output than those without... Not always the case though!
Onboard preamps do exactly the same thing as the preamp in your amplifier, but often with wider frequency blocks. For example, my bass has a 3-band (B/M/T) EQ preamp but my amp has a 4-band (B/LM/HM/T) preamp. Some amplifiers have more bands... Like Trace Elliot's 12-band graphic EQ on their AH1000.
Just a brief description, but maybe someone with more knowledge can elaborate?
Hope this has helped!
Fender USA Deluxe Jazz V
Squier CV 60's Precision
GK Fusion 550
Mesa Powerhouse Traditional 6x10

martyforrer
Gold Member
Posts: 654
Joined: Thu Apr 09, 2009 4:25 pm
Bands / Groups: Borderline.... country rock
Blues Deluxe... jazz/blues/jump
Cabin Fevre..... Americana
Marty's Juke Joint.... 40s & 50s boogie woogie, rock n roll, jump blues.
Location: Napier.

Re: What does a bass 'preamp' do?

Post by martyforrer » Thu Feb 28, 2013 11:50 am

A preamp is necessary to amplify the miniscule signal coming from your pickups so the power amp can get a decent shot at amplifying it. All bass heads consist of a preamp and a power amp. The tone controls on the amp are part of the preamp section. A preamp on a bass guitar is just a glorified tone control system.

foal30
Gold Member
Posts: 1746
Joined: Fri Dec 01, 2006 8:36 pm
MySpace Page: myspace is owned by Lucifer himself
Bands / Groups: Pony Jones
Location: Chch

Re: What does a bass 'preamp' do?

Post by foal30 » Thu Feb 28, 2013 7:39 pm

and if you have a Fender Jazz got a Sadowsky outboard
Slave to the Rhythm Changes

martyforrer
Gold Member
Posts: 654
Joined: Thu Apr 09, 2009 4:25 pm
Bands / Groups: Borderline.... country rock
Blues Deluxe... jazz/blues/jump
Cabin Fevre..... Americana
Marty's Juke Joint.... 40s & 50s boogie woogie, rock n roll, jump blues.
Location: Napier.

Re: What does a bass 'preamp' do?

Post by martyforrer » Mon Mar 04, 2013 10:53 am

foal30 wrote:and if you have a Fender Jazz got a Sadowsky outboard
Or a J-Retro..... much more versatile than the Sadowsky.

Tim1
Gold Member
Posts: 269
Joined: Mon Oct 22, 2007 7:54 am

Re: What does a bass 'preamp' do?

Post by Tim1 » Sat Mar 30, 2013 12:16 pm

Or leave it as it is and accept that Leo got it right in the first place :D . I have always preferred passive to active basses, partly because I believe they sit more naturally in the mix. Depends on your style, I suppose, but I ain't no virtuoso and a passive P or Jazz is pretty close to heaven for me. Tried the Sadowsky add on active preamp many years ago with a J but discarded it - all very subjective and subjective I know.

mickeyj4j
Bronze Member
Posts: 31
Joined: Thu Aug 27, 2015 9:14 pm

Re: What does a bass 'preamp' do?

Post by mickeyj4j » Fri Aug 28, 2015 10:48 am

Tech 21 have the sansamp bass driver di which is a good pedal but they are not cheep. $379 TECH 21 SANSAMP BASS DRIVER DI AND PREAMP EFFECT PEDAL
Behringer make a copy V-TONE BASS DRIVER DI BDI21 I have one and its great pedal lots of clean to overdrive sounds. I can really tone out the overly muddy thump of the low B string on my aria 5 string bass and give it a warmth and bether sounding tone. For the price $55 you can't go wrong. Behringer BDI21 V Tone Bass Amp Modeler with Preamp/DI. Behringer stuff has been hard to get and over the years different stores have had them. (Currently musicworks.co.nz is the official stockest hope they stay that way).

**Note** I understand this thread is a bit old but am adding some info to the topic for people interested in this subject.

mickeyj4j
Bronze Member
Posts: 31
Joined: Thu Aug 27, 2015 9:14 pm

Re: What does a bass 'preamp' do?

Post by mickeyj4j » Fri Aug 28, 2015 11:48 am

oops double of post above

Post Reply