Ignorant Newbie Question

Happy Face · March 04, 2014, 10:30:43 AM

Can you make any passive bass active by jamming in a preamp? Or should you use specific pickups?

amptech · March 04, 2014, 10:44:05 AM

Yup, you can use practically any pickup and have a preamp after it; booster, tone cct. and whatever you want. Or you could go all the way and join the fuzz tone club! (mud bucker with fuzz cct.)

There might be some trial and error finding the right preamp for your pickup, but there must be a lot of threads for this.
Current drain (battery lifetime) and signal/noise are common issues, but there are good designs out there.
Personally I do not use active cct´s in my basses (except for my EB0F of course

) but in some situations i can see why people use them.

Dave W · March 04, 2014, 09:13:14 PM

Most active basses are actually active preamps mated with passive pickups. The original EMGs are the major exception, they're internally active.

amptech · March 05, 2014, 02:17:36 AM

Many who wants to go active just needs to boost the pickups, but a boost pedal probably does the job - and then if you don'd like it you can just trade it for another or something. I even once bought a pedal eq for a horrible bass. At least you don't make a mess in the control cavity.. Another idea is to bypass the controls (wire the pickup directly to the output jack) and work on the new onboard preamp
outside the cavity, if you are not allready experienced in this field.

Happy Face · March 05, 2014, 06:15:09 AM

Thanks gents. A difficult to reverse mod is always a worry.

godofthunder · March 05, 2014, 08:27:53 AM

Years ago I had a DOD Bi-Fet pre amp pedal. I loved that thing, simple gain and tone controls it could really put some Umph in a passive bass.

gearHed289 · March 05, 2014, 09:21:57 AM

I used EMGs for about 15 years before going back to all passive (except for my fretless). What I do now is run everything through a Sadowsky preamp pedal. It's just got knobs for bass boost, treble boost (no cut), and volume. It also has a tuner output and a mute switch, which is nice - one less thing in the signal path. I go easy on the boosts - about 10 o'clock on the bass and 11 o'clock on the treble. I've found that the more you boost, the more mids get lost, and that's where the "character" of individual basses seems to come from. The more you boost, the more everything starts to sound the same. It REALLY gives a great starting point for the sound guy to work with, especially if you're only getting a DI.

Happy Face · March 05, 2014, 10:18:56 AM

Thanks for the wisdom.

I'd have an active bass in my stable until recently. I especially miss the sounds I could get from an Alembic or the Ricky I put Alembic pickups and preamp into.

I'm seriously pondering doing the same with one of my Guilds which have the neck profile I love best. Was wondering if I'd have to change the pups as well as putting in a different circuit. Best of all worlds?

slinkp · March 05, 2014, 10:23:57 AM

I think the main reasons to use a preamp are:

1) the pickups are weak (but I have not found that to be a problem even with my Danelectro; just turn up the amp!)

2) the bass came with a preamp that is integral to its characteristic sound (eg. Alembic ... or maybe the old Music Man basses)

3) the preamp gives you some control that you like having at your fingertips always, and that you wouldn't have without it.

In the latter category, I still have my much-abused Ibanez blazer with added Alembic Activator pickup & preamp combination. The tone control on these is unusual - it's a slightly resonant lowpass circuit and the knob adjusts the cutoff frequency. More like the "filter" slider you see on a lot of old analog synthesizers. The resonance is not adjustable (just as well, I'd probably just f*** things up).

So the bass is a bit of a chameleon, and turning the knob changes character quite significantly, while always preserving lows.
Still one of my favorite one-knob tone control designs ever. But I'm not sure it would work well with a pickup that already had a strong personality. Would have to try it.

I rarely if ever turned it DURING a song, so technically I could have got similar results with an outboard tone control, but I still love that bass and that knob is an important part of it to me.

All of this was a happy accident. I wasn't happy with my sound (in retrospect, I blame my shitty Peavey amp) and kept trying different things. I bought the Alembic pickups because I was a huge Entwistle fan and he was playing Alembics at the time. I had no idea I would come to love that tone control.

hieronymous · March 05, 2014, 11:40:59 AM

You might want to consider picking up a used Alembic SF-2 - it's two Alembic filters that can be run in mono & combined with the direct signal, or run separately in stereo. It's a pretty amazing device! You can use one filter to boost deep bass frequencies, and the other to set the filter cutoff for the range of sounds that Alembics are known for. That can mean sizzling high end, but it can also mean more flatwound-like sounds from roundwound strings with the filter cutoff at lower settings.

hieronymous · March 05, 2014, 11:44:16 AM

Quote from: slinkp on March 05, 2014, 10:23:57 AMIn the latter category, I still have my much-abused Ibanez blazer with added Alembic Activator pickup & preamp combination. The tone control on these is unusual - it's a slightly resonant lowpass circuit and the knob adjusts the cutoff frequency. More like the "filter" slider you see on a lot of old analog synthesizers. The resonance is not adjustable (just as well, I'd probably just f*** things up).

So the bass is a bit of a chameleon, and turning the knob changes character quite significantly, while always preserving lows.
Still one of my favorite one-knob tone control designs ever. But I'm not sure it would work well with a pickup that already had a strong personality. Would have to try it.

I rarely if ever turned it DURING a song, so technically I could have got similar results with an outboard tone control, but I still love that bass and that knob is an important part of it to me.

All of this was a happy accident. I wasn't happy with my sound (in retrospect, I blame my shitty Peavey amp) and kept trying different things. I bought the Alembic pickups because I was a huge Entwistle fan and he was playing Alembics at the time. I had no idea I would come to love that tone control.

I finally had a 3-position Q-switch put in to my Activator equipped bass - makes a huge difference! With the preset Q-bump it boosted the bass too much at lower settings - didn't balance with the higher settings - now I can have zero boost for deeper sounds, then more if I want to accentuate higher frequencies.

Linking to my previous post, the SF-2 does have variable Q with a rotary knob instead of switch.

Happy Face · March 05, 2014, 12:30:11 PM

Thanks Hieronymous. I was hoping you'd chip in.

And thanks to everyone. There's a wealth of info here, isn't there?

Dave W · March 05, 2014, 12:39:57 PM

Quote from: slinkp on March 05, 2014, 10:23:57 AM
I think the main reasons to use a preamp are:

1) the pickups are weak (but I have not found that to be a problem even with my Danelectro; just turn up the amp!)

2) the bass came with a preamp that is integral to its characteristic sound (eg. Alembic ... or maybe the old Music Man basses)

3) the preamp gives you some control that you like having at your fingertips always, and that you wouldn't have without it.

....

There are basses whose pickups were designed to be mated with a preamp, like the MusicMan, but if you're thinking of adding one, the real reason is No. 3. It's a matter of convenience and control. You can get the same thing in an outboard preamp pedal -- e.g. that's why Sadowsky made his original external pedal, to bring the same circuit from the onboard preamp in his basses to a pedal so you could use it without modding your vintage bass. For that matter, you can get control from the preamp section of your amp head. It's just not as convenient as doing it on the bass.

Happy Face · March 05, 2014, 02:38:37 PM

"the real reason is No. 3. It's a matter of convenience and control. You can get the same thing in an outboard preamp pedal -- e.g. that's why Sadowsky made his original external pedal, to bring the same circuit from the onboard preamp in his basses to a pedal so you could use it without modding your vintage bass. For that matter, you can get control from the preamp section of your amp head. It's just not as convenient as doing it on the bass."

In other bands I had the luxury of turning around and changing tone controls on my amp, especially after I changed basses. Which I'd do a lot being in a cover band, swapping between a bass with rounds and a bass with flats.

But now I'm in a "march or die" band that strives for 5 second pauses between many songs. Having a bass where I could make radical tone chhanges on the fly would be very helpful. No doubt a pedal would do the trick as well, but the bass in question is refinished and modded already so no harm done.

hieronymous · March 05, 2014, 04:59:47 PM

I have told Mica Wickersham of Alembic that I would love a stomp-box version of the SF-2, even with just one filter, with expression pedal control for the cutoff at the very least. That way you could easily go between different settings, even mid-song. I have considered setting each channel of the SF-2 to different settings, then using an A/B box to switch between the two, but that's getting too complicated.

Maybe something like the Tech 21 VT Bass Deluxe? You can set up to six presets. Question is, whether SVT sound is what you are going after. You could do a modeling unit like the POD, but that is digital, not sure you want to go that route (the Tech 21 is analog signal path with digital switching)

I think we need more info regarding what kind of sound/s you are going for. Do you need "modern" high end sizzle? Or are you looking for varieties of drive/clean?