Active - please explain

[scrumpymike]

Just deciding on a new bass and not sure which way to go with the electronics. Never owned an active but my preferred control layout on passive basses is 2 pups with 3-way selector switch plus 1 vol and 1 tone pot. With active electronics, do you get a pan knob that effectively does an even better job than a selector switch by allowing you to steplessly sweep across the complete tonal spectrum (assuming you have the volume up on both pups)?

Also, as my amp head has 2 inputs - active and passive - could I gig with an active and a passive bass both plugged in at the same time to allow for a quick change-over between songs (obviously with the volume turned down on the one I'm not playing)?

[cheddatom]

you can get pickup blend pots on passive instruments, no need for it to be active

you can plug any basses into either input on your amp, and two at the same time would be fine. Your passive bass into the active input might be a bit too quiet

With an active instrument, you generally get some sort of EQ which is much more powerful than a passive tone pot. They are normally louder than a passive instrument too

[HowieBass]

Another vote for an active instrument is that the signal is buffered so longer cables won't affect tone as they might with passive instruments. Some active basses use pickup selector switches and one volume. There are quite a few basses with active/passive options, some that just apply no tone EQ when in passive mode, others offer a master tone control (treble cut) in passive mode. A number of active basses have 3 band EQ and offer a choice of frequencies for the mids using mini-toggle switches. Time to go audition a few basses!

[GreeneKing]

As Tom says.

Passive tone control takes away. Active usually does +/- and in a set range of frequency. Some basses are 2EQ, treble and bass, others are 3 or 4 adding mid control.

Many active basses have an active passive switch so you can change if you prefer or if you get caught out with a low battery. Some even give you passive tone control as well.

Depending on the active EQ you may get other added 'bells and whistles' like adjustability 'under the hood' or a bright switch.

Edited December 21, 2016 by GreeneKing

[NickD]

As above, you can have a pan pot on a passive. My Jake+ usually has Vol, Vol, Tone, but I asked Adrian if there was any technical reason he couldn't make it Vol, Pan, Tone, and he said it would be fine... and it is. Between the controls it has it's easily as versatile as my active Elwood. I find on the Elwood I change my tone mostly with the pan pot and serial/parallel switch... The bass and treble boost/cut controls may as well not be there.

[yorks5stringer]

Can I be the first along to warn you if you have an active bass it [b]may[/b] cut out mid song due to battery death...! Never happened to me, but just one more thing to worry about ( and one more thing to carry in your case)!

Am sure it's a warning put out by passive bass makers and Duracell!

As mentioned above some have circuits which allow passive only if the battery dies, mine (Seymour Duncan Steve Baily 4 band) starts to distort and warns if the battery runs low.

Edited December 21, 2016 by yorks5stringer

[dannybuoy]

Some active preamps, although Audere is the only one I'm aware of, buffer each pickup individually and then blend them like an active mixer. This reduces the interaction effects between the pickups giving you a nice gradual blend between the two rather than what you usually get which is a sharp drop off as soon as you nudge the blend either way off centre.

[BassBunny]

[quote name='dannybuoy' timestamp='1482335373' post='3199686']
Some active preamps, although Audere is the only one I'm aware of, buffer each pickup individually and then blend them like an active mixer. This reduces the interaction effects between the pickups giving you a nice gradual blend between the two rather than what you usually get which is a sharp drop off as soon as you nudge the blend either way off centre.
[/quote]
East, Noll and Glockenklang do as well as far as I am aware. In fact Noll make an active blend that you can add to a passive instrument and get the best of both worlds.

[Woodinblack]

[quote name='yorks5stringer' timestamp='1482335179' post='3199685']
Can I be the first along to warn you if you have an active bass it [b]may[/b] cut out mid song due to battery death...!
[/quote]

Has that ever happened to anyone? I can't think of a way you would do a circuit where it would actually cut out due to battery death, as batteries tend to get flat, not just die. As a result, you will just start to get clipping, and as most batteries discharge quite slowly with the sort of power an acitve circuit needs.
Certainly never heard of it actually happening since I got my first active bass in the 80s.

Anyway, The answer is that there is no direct answer. Most circuits take advantage of the active circuit to add bass and treble controls, but the whole point of an active bass is to buffer the low level signal from the bass and stop treble loss and noise in the cable.
Some don't bother with this - the G&L L2500 is exactly the same tone controls in passive or active, the only difference is there is a mode with a treble bright switch. There is no real difference between normal passive and active on that, if you have a short perfect cable.

[Woodinblack]

My Elwood has a pan control, and as you know, the pickups are quite different, a P and a Humbucker.

There are 5 clear tones, full way both ways, the sound of just the P or the J, in between, a varying sound between the two, and then a specific different sound just at the point you turn away from one pickup, which is completely unique.

I am not a fan of two volumes. Volume / Pan always seems better to me.

[scrumpymike]

Thanks for the useful info everybody but still not clear: is it still worth having a pup selector switch if I go for an active bass?

[Woodinblack]

For me I would say not, I would have what I have on mine, which is Volume, Pan, Treble, bass, but it depends on the way you play

[markstuk]

If you have more than two pickups ?

[yorks5stringer]

[quote name='Woodinblack' timestamp='1482341663' post='3199759']


Has that ever happened to anyone? I can't think of a way you would do a circuit where it would actually cut out due to battery death, as batteries tend to get flat, not just die. As a result, you will just start to get clipping, and as most batteries discharge quite slowly with the sort of power an acitve circuit needs.
Certainly never heard of it actually happening since I got my first active bass in the 80s.

[/quote]

It was tongue in cheek as many seem to quote this as an issue with an active bass...like I said, I got some distortion/clipping as warning. I suppose the other issue is if you are used to leaving your Bass plugged in all the time (maybe as I do at home with a passive), with an active you will use up the battery quicker.

[GreeneKing]

[quote name='BassBunny' timestamp='1482340831' post='3199754']
East, Noll and Glockenklang do as well as far as I am aware. In fact Noll make an active blend that you can add to a passive instrument and get the best of both worlds.
[/quote]

The new East Uni pre has an active and a passive blend. When you switch the type of blend switches. There's also trimmable pots to adjust the individual pickup levels. So you have all the merits of a simple switch plus infinite blend settings.

[stingrayPete1977]

My East circuit gives no warning at all, but I always have a spare bass at a gig and a spare battery at a practice. Everytime I've had a total failure it's been a broken wire sort of deal, active/passive being irrelevant.

[kodiakblair]

Can anyone shed light on active pickup/passive pots ?

My recent Peavey RSB has them but I'm stumped for reason.

[Woodinblack]

What do you mean by active pickups / passive pots? do you mean the pickups are powered and the wiring is just like an ordinary passive circuit?
That is just the same as if you replaced the pickups in any other passive bass, you get the advantage of the lower impedance and noise reduction. If that is factory fitted I assume they have a model without the active pickups.

[TrevorR]

[quote name='Woodinblack' timestamp='1482341663' post='3199759']

Anyway, The answer is that there is no direct answer. Most circuits take advantage of the active circuit to add bass and treble controls, but the whole point of an active bass is to buffer the low level signal from the bass and stop treble loss and noise in the cable.
Some don't bother with this - the G&L L2500 is exactly the same tone controls in passive or active...
[/quote]
[quote name='kodiakblair' timestamp='1482347424' post='3199825']
Can anyone shed light on active pickup/passive pots ?

My recent Peavey RSB has them but I'm stumped for reason.
[/quote]

See Woodinblack's answer above for the reason. Have watched some YT vids testing different lengths of cable run with and without any active buffer. If they're true on long runs the difference is remarkable.

[lowhand_mike]

[quote name='markstuk' timestamp='1482345533' post='3199807']
If you have more than two pickups ?
[/quote]
what is this sorcery of which you speak?

personally i like the boost/cut of the EQ where a passive just gives you cut. mine has a volume and pickup pan and a passive switch so im covered but for multi pickups you either need volume for each or a selecta

[stingrayPete1977]

My Jazz hasn't got volume for each or a selector, it's master volume then a pickup pan knob, stacked bass/treble. I always prefer a single volume knob to fade my volume down on stage, I'm yet to meet a passive bass I like, every one I've had has ended up with a circuit stuffed inside!

[kodiakblair]

[quote name='Woodinblack' timestamp='1482349157' post='3199842']
What do you mean by active pickups / passive pots? do you mean the pickups are powered and the wiring is just like an ordinary passive circuit?
That is just the same as if you replaced the pickups in any other passive bass, you get the advantage of the lower impedance and noise reduction. If that is factory fitted I assume they have a model without the active pickups.
[/quote]

That's exactly what I mean. Pickups are connected to 9V battery,passive Vol,Tone & Blend. This was the only version of the model.
Manual tells you very little, just says clockwise for more treble/anticlockwise for more bass.

I'm not complaining as I prefer it to the earlier Sarzo bass with it's 3 Band EQ and trimpots.

[darkandrew]

[quote name='kodiakblair' timestamp='1482347424' post='3199825']
Can anyone shed light on active pickup/passive pots ?
[/quote]
Basically the problem that pickup designers have is that they need to juggle output, inductance and capacitance; generally the more winds of wire you put on a pickup, the higher the output will be but also it will have increased inductance and capacitance which will adversely affect its frequency response. Fewer winds will give a flatter response but at too low an output, so you have to build a preamp into the pickup to raise the level - this is essentially an active pickup. The output from this can then be shaped using a simple resistor/capacitor arrangement to short varying amounts of high frequencies to ground (passive tone control) or another preamp that actively boosts or reduces varying amounts of specific frequencies (active tone control). Some active tone control circuits can be bypassed with a switch to re-route the signal if the battery dies but an active pickup cannot be switched in a similar way.

Edited December 22, 2016 by darkandrew

[chris_b]

[quote name='scrumpymike' timestamp='1482319350' post='3199475']
Just deciding on a new bass and not sure which way to go with the electronics.
[/quote]

What kind of bass and what kind of sound are you after and how flexible do you need to be?

I run my Precision with flats and IMO it sounds best as a passive bass. My 2 pickup basses have round wounds and are are active. 2 of them have 3 band pre amps.

I've just been checking out an active J type bass that has a 3 band pre amp with a switchable mid range centre and 4 trim pots. I'm not sure I have a need for that amount of flexibility but in the end it's all about how good the bass sounds.

[kodiakblair]

Thanks for that darkandrew.

Perfect explanation.