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Discussion Starter · #1 ·
Hello,

Can you quickly describe me the purpose / usage for Bass DI / preamp pedals.
I have active Czech made Spector with single coil EMGs. It has built in preamp powered by 9v battery.

When I plug in into mixer / monitors, it sounds great.

I purchased from amazon couple of different DI boxes (Ampeg SCR-DI and Ampleg preamp Classic. Eden world traveller, MXR 80 I think (and returned all of them))..

I don't see/understand their purpose.
Ampeg SCR-DI I liked but the sounds is so similar between all of them (and without them) that I don't really understand.

Eden could produce wide variety of sounds. Amper SCR-DI had a really nice punchy sound.

But still, yes there are differences, but they are so subtle that when played you wouldn't know the difference.

Is it because the bass is active and it would be big difference on passive bass or?

I was expecting big difference like with guitar/amps/pedals.

But for bass everything is so subtle. And even better whatever I use / do - it always sounds great.


Let me know your thoughts
 

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DI is for exactly that - go to the FOH so that the person running sound can control your levels out front. The preamp would be for shaping the tone of said DI sound (since no one likes bad tone). A lot of people run the sansamp di into a bass amp as tonal shaping. Many bass heads also have DI outs now.
 

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Discussion Starter · #3 ·
ok, that I understand. But there are so little difference between going straight from bass into mixer, and bass -> DI -> Mixer, that I am on "why bother" camp.
Yes you have a little more EQ options - but I have those in mixer as well.
Yes some DI pedals give a little but different sound - but the difference is so little...

Is it possible the reason is that bass is active, so that EMGs are already doing that pre-amplification? Or it would be the same with any kind of bass
 

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ok, that I understand. But there are so little difference between going straight from bass into mixer, and bass -> DI -> Mixer, that I am on "why bother" camp.

...
Is it possible the reason is that bass is active, so that EMGs are already doing that pre-amplification? Or it would be the same with any kind of bass
There is a difference. If it has worked for you it is NOT because the bass is active (if anything that would, most likely - see final paragraph, make the impedance mismatch between the mixer LoZ mic inputs and the HiZ output of the bass worse as active [usually] = higher level signal than passive). What I suspect is that the mixer has a 1/4" line input which is tolerant of HiZ signals. Not unheard of. Some mixers even have built in DI inputs on at least a channel or two. This is likely what is happening here; you are using a DI (or a tollerant / well designed line level input) vs the typical XLR mic input. Everything has got a DI these days so you could be using one and not know it.

The purpose of a DI is twofold: convert unbalanced 1/4" output to balanced XLR and to convert the signal level. All the tone shaping stuff (the 'preamp' part) is gravey and as you said not needed if you are otherwise happy in that regard.

There is also the slim possibility (I am not familiar with your bass) that you are using an instrument with LoZ output. This can be achieved via LoZ pickups (such as the ones in my Gibson LP Triumph bass, see also LP Recording/Professional/Personal models from the 70s) or via active electronics (providing a balanced XLR output on the bass itself) though this is not common at all.
 

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There is a difference. If it has worked for you it is NOT because the bass is active (if anything that would, most likely - see final paragraph, make the impedance mismatch between the mixer LoZ mic inputs and the HiZ output of the bass worse as active [usually] = higher level signal than passive). What I suspect is that the mixer has a 1/4" line input which is tolerant of HiZ signals. Not unheard of. Some mixers even have built in DI inputs on at least a channel or two. This is likely what is happening here; you are using a DI (or a tollerant / well designed line level input) vs the typical XLR mic input. Everything has got a DI these days so you could be using one and not know it.

The purpose of a DI is twofold: convert unbalanced 1/4" output to balanced XLR and to convert the signal level. All the tone shaping stuff (the 'preamp' part) is gravey and as you said not needed if you are otherwise happy in that regard.

There is also the slim possibility (I am not familiar with your bass) that you are using an instrument with LoZ output. This can be achieved via LoZ pickups (such as the ones in my Gibson LP Triumph bass, see also LP Recording/Professional/Personal models from the 70s) or via active electronics (providing a balanced XLR output on the bass itself) though this is not common at all.
Active EMG pickups have an internal preamp and are low impedance output.
 

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Active EMG pickups have an internal preamp and are low impedance output.
Didn't know that about EMGs in particular (all of them or just some - coulda swore some were HiZ cuz guitarists generally hate LoZ outputs - but never personally owned them, so dunno?) but that would def explain it as I said above.
 

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Didn't know that about EMGs in particular (all of them or just some - coulda swore some were HiZ cuz guitarists generally hate LoZ outputs - but never personally owned them, so dunno?) but that would def explain it as I said above.
There used to be EMG-HZ pickups (maybe still are?) which were passive and Hi-Z. Commonly used on mid-range import guitars. Before being called EMG-HZ I believe they were called "Select by EMG".
 
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