why should i use a on/outboard preamp?

[Rokoko]

Hi everybody

i have played bass for bout 10 years, both passive and active ones, and i just recently got round to wondereing if i should use some kind of preamp with my fender jazz.

The thing is, i dont have miles of cable run, and im playing on a decent amp (GK 150MB-IIIE). So even though im used to guitar DIY i cant really figure out what a simple preamp (aguilar DB924, Audere JZ3 etc) will give me that my amp hasn't got already.

might be a vague question, hoping for a clear answer though

Best regards
Johan

[Bruce Lindfield]

They are great with passive basses - but not much use on active ones..?

[Rokoko]

That much i know. But why not just boost bass/treble om the amp?

[Bruce Lindfield]

I think you tend to lose something and there are also issues about impedance. If your amp has an input specifically designed for passive basses and you always use this - then you probably don't need it - but if you are likely to be turning up at gigs where you just plug in to what is there - then they can be very useful to keep your own sound.

They are also essential for piezo ..?

[mech]

I like on-board pre amps because they let me change the tone between or during songs without going to the amp. If you are satisfied with the tonal sounds available with the current controls on your bass all night or don't mind going to the amp to make changes, it won't really do anything for you.

A pre with an active/passive switch gives the best of all options.

mech

[SGD Lutherie]

The reason I like on board preamps is that I can change the tone from song to song, and the preamp preserves my tone no matter what I plug into. My amp only has a 7 band EQ, so I do all my tone shaping from the bass. I set the amp up for a good tone in the room with the bass' controls set flat.

You do not lose anything with preamps, but you do lose something with passive basses. The thing is people are used to the tone of passive basses, so they think that's the real sound of the pickups; but it's not.

With a passive bass your controls and cable are loading the pickups. Both because of impedance and capacitance. What you get is some of the highs rolled off and the pickup's resonance peak is lowered.

Another advantage to active basses is you can plug directly into a mixer for recording without using a DI box.

[SGD Lutherie]

Originally Posted by Bruce Lindfield

If your amp has an input specifically designed for passive basses and you always use this

The passive/active inputs, or switches only pad the input to reduce the level. I prefer to use the passive input with active basses with my amp. I get a hotter signal.

They are also essential for piezo ..?

Yes, you cannot use a piezo passive. Well you can, but they don't sound very good. They sound scratchy and harsh because of the impedance mismatch.

[4Mal]

Originally Posted by Bruce Lindfield

They are also essential for piezo ..?

That depends entirely on the piezo system used. The Shadow system in my Kala sounds great w/o preamp. I also have basses with Graphtech and LR Baggs - both those need the preamp.

On board pre-amps, other than for those two piezo systems are really a matter of taste. My taste says no in general.

[depalm]

I have a bunch of passive and active basses and I choose whatever suits better the situation.

Onboard preamps are nice because you have the freedom to shape your tone by yourself, on a recording session with many musicians requiring the engineers attention is easy to get lost in the mix and playing "blind". With a good preamp you can tweak a bit and get back on track.

On certain boomy stages you can cut some low end to get things a bit clear.

I also like how some kind of preamps adds "color" to instruments tone.