Active pickups vs passive + pedal preamp

[LiturghianPope]

Hello everyone,

 

I am trying to understand the difference between using an active pickup compared to a passive pickup + an external (I mean, outside of the bass) preamp. I guess it's much more versatile to use passive pickups since it offers the possibility to try various preamp pedals, right? But what are the downsides to this?

 

I guess that until not long ago I just took for granted that active pickups are the way to go, especially for heavy music, due to their higher output, but now I'm trying to better understand what are the implications of these two different technologies/approaches.

 

Are active pickups designed different knowing they will be marketed and sold followed by a preamp? Or are they just regular pickups and the whole 'active' pickup thing is just the (optional) addition of a preamp?

 

Thanks in advance looking forward to hear your opinions and past experiences with these two different kinds of pickups.

Edited March 3 by LiturghianPope

[MrDinsdale]

Active basses can be quieter than passive basses, it completely depends on the preamp and pickups. Many active basses have passive pickups, it’s the preamp that is active. Stuff like EMG has active pickups and preamps.

 

You can also use active basses and preamp pedals. Some people don’t like having many preamps/eqs in the signal chain as they might mess with the transparency of the tone etc or have multiple eqs interacting/fighting with each other.

 

I’ve used all kinds of combos but I’ve landed on passive mid output pickups and a stellartone tone pot or similar. I’m very keen to try the Lusithand NFP preamp though which acts like a Wal.

 

I actually have 2 preamps in my signal chain always on, the Jad freer Capo and EAE Model feT. That then runs into the front of my amp. This gets me a great basic tone which I can then layer grit to.

 

Just do what sounds good and fits the context. 

[BassAdder60]

Onboard bass preamp is useful for tone changes on the fly but personally I’m a passive pickup user and preamp on the floor or amp kind of player 

 

I find the tone from passive basses more to my liking 

[Boodang]

The mechanics; the more windings on a pickup the higher the output but narrower the bandwidth. So a passive pickup will have enough windings for a usable output but not much response above 4k. To get around this an active pickup will have few windings, a full bandwidth and to get over the very low output, a built in op-amp to boost the signal (hence the need for a battery). 
passive pups also have an output impedance fixed by the number of windings (usually around 10k ohms) whereas active pups have an output impedance set by the op-amp which can be 10k or as low as 600/300 ohms, in which case it’s a line driver and the capacitance of the cable will not effect the top end (ie roll off treble).

In practice it means active pups tend to have more top end and are brighter. There’s a good YouTube vid where someone goes through multiple types of replacement pups on a jazz, as soon as he plays the emg’s it’s a bright tone. If you want that bright hi-fi tone then actives are the way to go as no amount of boosting the top end will get what you want from a passive pup as it doesn’t have the bandwidth. Of course you can still eq an active pup but you might find a passive one does that for you. 
‘Organic’ is a phrase often used for the tone of a passive pup but that’s basically because it’s applying its own eq by virtue of a limited bandwidth. 

[Boodang]

As to which pickups I favour… it used to be active emg’s but I just ended up rolling off the treble. Now I only use passive pups, I get custom ones made to get as close to the tone I’m after straight out. So for my P the response is very mid heavy and cuts thru, for my jazz it’s alnico2 magnets on the bridge for more mids, and alnico5 on the neck for more bass. 
Pickup design is a rabbit hole. Different magnets, magnet size/shape, windings and wire diameter… there’s an endless combination. But nothing I like more than discussing a new custom pickup design and then seeing what the results are like. 

[Boodang]

13 hours ago, LiturghianPope said:

Are active pickups designed different knowing they will be marketed and sold followed by a preamp? Or are they just regular pickups and the whole 'active' pickup thing is just the (optional) addition of a preamp?

 

A quick note regarding pre-amps... these are completely separate to active pickups and you can use an active preamp with a passive or active pup*. A passive preamp can only cut frequencies (typically treble roll off), whereas an active preamp will also be able to boost frequency bands and possible have a line driver as well to reduce the line impedance. An active preamp can be quite useful as you can install one that works well with a specific bass. However you can just use an external preamp (on your amp, pedal or rack) to do the same job. 

* There are some exceptions; active pups have an op amp so they are buffered. This means that you could blend two active pups in parallel but you can't put them in series. So you can't install a series/parallel switch on a bass with active pups. Also, there are a few preamps that have pickup impedance loading options but again, as an active pup is buffered you can't do that either. 

[SimonK]

I use Stingrays with active pickups, and have just thought it was to do with the designers preference for how they want the pickup to sound, coupled with the convenience of being able to boost frequencies directly on the guitar (rather than just cut). Granted off-instrument preamps kind of do the same thing, but for me the convenience of a preamp pedal is to add some more colour on top of the sound of the bass itself. Granted I have often not used any external preamp, going straight into DI, but having an extra box on the floor with some EQ/tone options can be quite helpful especially when moving between different rooms/bands and needing to tweak a sound to fit the mix. Nothing ever sounds the same as you move between different contexts so the more tweakery the better!

[Boodang]

14 minutes ago, SimonK said:

I use Stingrays with active pickups, and have just thought it was to do with the designers preference for how they want the pickup to sound, coupled with the convenience of being able to boost frequencies directly on the guitar (rather than just cut).

Active pickups or passive pickups with an active preamp?

A lot of manufacturers install active preamps as it gives you a lot of tone sculpting power. 

[SimonK]

5 minutes ago, Boodang said:

Active pickups or passive pickups with an active preamp?

A lot of manufacturers install active preamps as it gives you a lot of tone sculpting power. 

 

Ooh good point - its the stock pickups which means, I think, they are indeed passive pickups with active onboard preamp. But from a practical players perspective it is often anything that needs a battery in the guitar, vs anything that doesn't - but I get the technical difference!

Edited March 4 by SimonK

[itu]

pickup - vol - tone stack - output

 

pickups - blend (or vol) - vol - tone stack - output

 

Practically any component can be battery powered (low impedance, "active"). Some system are even PSU operated (like Alembic Series II).

 

Coil-magnet pickups are "passive" (high impedance, hi-Z) components. As @Boodang so well put earlier, the basic idea to modify a "passive" pickup to an "active" one, is to add a buffer to it (EMG and few others). Then the lower output can also be compensated with that buffer. Yes, there are active units like infra red sensors, but they are rare. I have used an acceleration sensor: response starts from DC... amplifier cries... the system has now some HP filtering.

 

NOTE: The output of a pickup can be adjusted by the amount of windings, or the buffer settings. Hi-Z pickup output may be far more powerful than its lo-Z sibling's.

 

The most common way to mix two pickups is to use two vol pots. Pots are of mediocre quality, but very cheap - and therefore so common. The complicated thing is that this way of mixing loads pickups: the sound is affected. Vol pots are tone pots, too.

 

Some preamps are mixers (John East, Noll Mixpot). They can adjust the levels of the pickups without loading the pickups. This way the blend adjustment is independent from each pickup, which certainly is not the case with a simple potentiometer based system.

 

Tone stack may be just a cap and a pot. Cheapo, but functional. If you see an ad of an "active bass", usually only the tone stack is battery powered. Did you notice that a £300 Sadowsky preamp has simple vol and blend pots in front of B&T?

 

A battery powered tone stack may be a tone, a filter (LPF), a two or a three band eq, a tilt eq, a semi-parametric... or nearly anything. There has been lots of solutions, although B&T is probably the most common at the moment. It is cheap, modern opamps have ultra low power consumption, and many of us like its simplicity.

 

One thing that you should find out yourself is the output impedance. It affects (this is something I have found out by testing lots of stuff, and interviewing people) the input of OD/dist/fuzz and some compressor pedals (I have different pedal boards for hi-Z and lo-Z basses). Maybe your pedals are less critical, some of mine aren't.

 

I do not see any reason you couldn't use an external preamp with any bass you have. You can use any effect pedal, and you can use any preamp you want. Trust your ears. Do not rely on opinions, only your ears. Like OC-2 was made for g-word players. Then Pino found it.

[itu]

16 hours ago, Boodang said:

...it’s alnico2 magnets on the bridge for more mids, and alnico5 on the neck for more bass...

 

Magnet type does not dictate the response of a pickup. The type may tell you the highest possible field it can produce around it, but that depends on the production process. Therefore a neodymium can be weaker than a ferrite.

 

10 hours ago, Boodang said:

...active pups have an op amp so they are buffered. This means that you could blend two active pups in parallel but you can't put them in series. So you can't install a series/parallel switch on a bass with active pups.

 

There are pickups like EMG TW and TWX:

https://www.emgpickups.com/bass.html

[LiturghianPope]

On 05/03/2024 at 00:33, itu said:

I do not see any reason you couldn't use an external preamp with any bass you have. You can use any effect pedal, and you can use any preamp you want. Trust your ears. Do not rely on opinions, only your ears.

 

There's a lot of stuff i didn't know and in order to understand some of it I need to make more research. This is definitely not the kind of stuff you can understand in a day.

 

And yes, I am trying to rely on the actual sound because that's after all, the whole point.

 

However, one of the underlying aspects of the question, besides wanting to better understand what's going on beneath the casing, was whether passive pickups would allow greater flexibility and the ability to try various different external preamps and hearing major differences, as opposed to active pickups which already use a preamp which has a certain profile.

 

I mean I'd like to try various pedals especially some darkglass ones since they're very popular for metal bass tones and I was wondering if the weight of those pedals in the whole signal chain doesn't diminish if a preamp is already there (the pickup premp). 

 

Meaning, maybe, I'll keep trying various pedals but there's something I won't like in the tone and that might be the preamp in the active pickups. Alternatively, changing the pickup preamps is highly inconvenient - I mean sure I'd like to try three or four preamp pedals, but I wouldn't change the pickup preamp three times. 

 

Am I being too theoretical and hypotethical here? Am I imagining some cause-effect relationships that don't really translate down in engineering/physics? Just trying to figure out if I should get active pickups or not, I'm currently playing on schecter diamond series and it took me a while to come to the conclusion that I don't like them. 

[Boodang]

31 minutes ago, LiturghianPope said:

 

There's a lot of stuff i didn't know and in order to understand some of it I need to make more research. This is definitely not the kind of stuff you can understand in a day.

 

And yes, I am trying to rely on the actual sound because that's after all, the whole point.

 

However, one of the underlying aspects of the question, besides wanting to better understand what's going on beneath the casing, was whether passive pickups would allow greater flexibility and the ability to try various different external preamps and hearing major differences, as opposed to active pickups which already use a preamp which has a certain profile.

 

I mean I'd like to try various pedals especially some darkglass ones since they're very popular for metal bass tones and I was wondering if the weight of those pedals in the whole signal chain doesn't diminish if a preamp is already there (the pickup premp). 

 

Meaning, maybe, I'll keep trying various pedals but there's something I won't like in the tone and that might be the preamp in the active pickups. Alternatively, changing the pickup preamps is highly inconvenient - I mean sure I'd like to try three or four preamp pedals, but I wouldn't change the pickup preamp three times. 

 

Am I being too theoretical and hypotethical here? Am I imagining some cause-effect relationships that don't really translate down in engineering/physics? Just trying to figure out if I should get active pickups or not, I'm currently playing on schecter diamond series and it took me a while to come to the conclusion that I don't like them. 

So, if anything, active pickups have less of a profile than passive pickups in the sense of their response. An active pup will generally have a wider bandwidth (especially top end) and have a flatter response than a passive pup which will have less above 3Khz. If you want flexibility, then active pups is the way to go as they have the greater frequency response. 

 

You can use an active preamp with either passive or active pups. For the greatest possibly flexibility use active pups with an active preamp. All you have to do now is try out / listen to the almost infinite combination of both available to you, especially if you decide to add some kind of pedal as well!

 

You could play it safe and go for EMG active pups and Aguilar active preamp as a good starting point. In terms of preamp pedals, well, there's as many opinions as to what to get as there are pedals, so good luck! Personally, in terms of eq shaping I just use a compressor pedal (just please don't ask what compressor pedal to get as you'll end up starting 'that' thread again!).

[itu]

7 hours ago, LiturghianPope said:

...whether passive pickups would allow greater flexibility and the ability to try various different external preamps and hearing major differences, as opposed to active pickups which already use a preamp which has a certain profile.

Again, @Boodang wrote some very good notes.

 

I want to add that as long as you use any passive, hi-Z components in between the pickups and the preamp, the response is sacrificed. Any pot, be it blend, vol, or tone, will degrade the original sound.

 

You want pure sound from the pickup, connect it directly to the preamp. You have two pickups, you should use some non-loading circuitry (Noll Mixpot or similar) between the two, or use two preamps, one for each pickup.