Passive Bass vs Active Bass in Passive Mode

[Lo-E]

Depending on the configuration

This phrase is the key to this whole topic.

“Active” is really a blanket statement that covers any and all circuits that contain a preamplifier and/or active EQ and/or buffer anywhere onboard the instrument. There can be any number of circuits that fit that description and some can be made completely passive and some can’t. It all depends upon the circuit’s topography and how the bypass is achieved. There are too many variables to answer your question with anything but “it depends.”

Totally fair: what about a bass with a Nordstrand 3 band bass preamp with active/passive switch and Nordstrand jazz pickups vs the same pickups in a vol/vol/tone passive setup?

If the active/passive switch is truly a bypass it should sound identical to a passive J.

 

[KidAmnesia]

Totally fair: what about a bass with a Nordstrand 3 band bass preamp with active/passive switch and Nordstrand jazz pickups vs the same pickups in a vol/vol/tone passive setup?

If the passive mode in that bass completely bypasses the preamp and leaves you with a VVT configuration, it should sound and behave like any passive jazz. If the switch does some other thing, the results may vary. Some basses will not have a tone knob in passive mode for example.

But generally speaking, yes, it should be pretty much the same.

 

[Cory rich40]

Just my 2 cents, something I just thought about and can’t believe I didn’t think about it sooner. I know that there are several on here that use basses that have the passive/active switch that feel like the volume decreases in passive mode. I’ve experienced this with my Ibanez basses. What if I switched my amp to passive mode after I switched my bass to passive. Somehow I’ve never thought to do this. I also realize that not all amps have the pad.

 

[DJmtd]

Like others have said, an active/passive switch physically bypasses the preamp. The switch is placed between the blend and master volume. In one position, it goes through the preamp before hitting the output. In the other position, it goes right to the output. If you like the same pickups in a completely passive bass, they will behave identically in an active/passive setup in passive mode. We include a passive tone control in the basses that come stock with a/p switches. I actually pulled mine because I like to have my tone wide open all the time.

Edit: I typed wrong - the switch on our pres is between the blend and master volume. I incorrectly said it goes between the volume and output, which would not work the way you want it to. You need the master after the pre, for obvious reasons.

I recently read a hilarious reddit thread where people were saying all kinds of wild stuff about what's going on in there and an active/passive switch makes it impossible to get 'true coil sound.' This is all nonsense.

MTD doesn't do well either.

Which ones have you tried? I tend to set my eq flat or with just a little mid bump, so active or passive doesn't really change much for me. On the other hand, a lot of people who play MTD do the Gouche thing and dime the entire preamp. If you're one of those types of players.... yeah it might be a little jarring to use passive mode

 

[ProbablyTooLoud]

@micguy curious to hear an acoustic physics take on this topic

 

[GIBrat51]

In your experience, is there much of a difference in tone between a passive bass versus a bass with an active preamp in passive mode? For example, a passive fender jazz versus a fender jazz with an active preamp in passive mode?

In my experience? Well... out of the 5 active basses I own, only one - a '15 G&L ASAT bass - has a "passive" mode. The Alembic, the Shecter, and the 2 Stingrays, are stone dead without a battery. There is no "passive mode" with them... As for the ASAT bass? No, there's no discernable difference in the tone - to my ears, anyway. Active tone is just... louder. TBH? It hasn't had a battery in it, for several years. If I want "louder"? I just turn the amp up... As has already been stated; how the bass is configured, is the determining factor - assuming the bass actually works in both modes...

 

[cfortner]

If you completely remove the preamp from the audio path using a two-position switch, an active bass with passive pickups in passive mode can sound exactly like a fully passive bass with the same pickups. To achieve this, neither the input nor the output of the preamp should be in contact with the circuitry while in passive mode and the resistance of the vol and tone pots should be identical in both modes (hi Z).

In addition, the preamp’s input should be shorted to ground in passive mode to prevent interference. Correctly, a three-way switch would therefore be necessary.

 

[BassicJazzy]

No difference.

 

[skier 913]

Totally fair: what about a bass with a Nordstrand 3 band bass preamp with active/passive switch and Nordstrand jazz pickups vs the same pickups in a vol/vol/tone passive setup?

nope. none. The key thing here is the pickups are the same. Some manufactures put different pickups in their active models vs their passive models.

 

[J Wilson]

To be precise, a so-called 'active bass' with a bypass switch is using passive pickups ganged to a battery driven boost/cut tone circuit.

Depending on the circuit(s) employed, passive or active operation can sound alike.

 

[ad9000]

It depends on the preamp. On most active basses that I own (or have owned) with active bypass there's little or no difference, but on my Alleva Coppola LG5 in active mode, with the tone controls set flat there's a little bit of a bump in high end and low end and a slight volume boost vs. passive mode. I haven't really investigated the signal path of the wiring to see why this is, but it doesn't bother me.

 

[MCS4]

Half my basses are Kiesel - they full on suck in passive mode. In all fairness they admit that (or they used to), saying it's just a temporary tool if your battery dies mid-show.

Not the case for me! I've played and gigged Carvin/Kiesel basses for decades and they have all sounded fine to me in passive mode. In particular my main Carvin LB70 is almost indistinguishable between the two modes if I leave the active EQ flat and use the internal trim pot on the preamp to match the passive and active volumes. I would much rather use that bass in passive mode versus pretty much any passive-only bass I have ever played. On my newer Kiesel Osiris there is a little more difference but they both sound good and I'm not really sure which I prefer. But everyone has different experiences and preferences.

 

[fourstringbliss]

In your experience, is there much of a difference in tone between a passive bass versus a bass with an active preamp in passive mode? For example, a passive fender jazz versus a fender jazz with an active preamp in passive mode?

This completely depends on the active circuit involved. Some active preamps have a baked-in tone which would be lost in passive mode. My favorite active preamps were made by Audere Audio and are completely transparent, giving passive tone when the EQ is flat. Unfortunately, they went out of business this year.

 

[fourstringbliss]

Just my 2 cents, something I just thought about and can’t believe I didn’t think about it sooner. I know that there are several on here that use basses that have the passive/active switch that feel like the volume decreases in passive mode. I’ve experienced this with my Ibanez basses. What if I switched my amp to passive mode after I switched my bass to passive. Somehow I’ve never thought to do this. I also realize that not all amps have the pad.

In basses with a passive/active switch I've rarely changed during a set, One option if you do switch would be to figure out where the volume knob should be in active mode so when you switch to passive you can dime it to match the volume.

 

[robert_stuart]

I've often wondered the same thing. I can believe it, that it depends on the bass's design.

I disagree that "if it runs without batteries, then the active circuit has no effect". I think it's possible that the passive circuit "sees" some components of the active circuit, which affect impedance, current, or frequency — even though the bass is still creating a sound.

For all the true passive effects, I'd only trust a 'true bypass'. And a big hint will be separate volume and tone controls for passive vs. active mode. I'm pretty sure the Fender Precision American Ultra II has this.

 

[dabbler]

This completely depends on the active circuit involved. Some active preamps have a baked-in tone which would be lost in passive mode. My favorite active preamps were made by Audere Audio and are completely transparent, giving passive tone when the EQ is flat. Unfortunately, they went out of business this year.

WHAT!?!?! Say it ain't so!! Nobody told me about this!!

Oh well, at least I got 3. Great pre's, IMO.

 

[fourstringbliss]

WHAT!?!?! Say it ain't so!! Nobody told me about this!!

Oh well, at least I got 3. Great pre's, IMO.

Yeah, and I was about to buy another one! The parts got too expensive for them to compete without lowering quality.

 

[Malak the Mad]

WHAT!?!?! Say it ain't so!! Nobody told me about this!!

Oh well, at least I got 3. Great pre's, IMO.

There's a thread or two about it somewhere on TB. I'm just wondering when they'll make good on the promise to turn the website into an info dump for those who've already bought one.

Yeah, and I was about to buy another one! The parts got too expensive for them to compete without lowering quality.

'Tis sad, but I get it. Cheers to them for not diving down the bottom of the barrel.

I lucked out and bought my first two off fellow TB'ers around the time they threw in the towel. Talk about cutting it close!

There's someone selling a five-stringer body in the classifieds that's decked out with an Audere. If it had an on-the-plate output jack instead of a side-jack port, I would've considered grabbing it just for the preamp and sold the rest.

 

[Yahboy]

On my Charvel Pro Mod PJ , both Active/Passive voice with onboard preamp sound totally different compare to fully passive mod ( A500K Volume / MN250K blend ).

 

[ga_edwards]

Depends. Passive isn't necessarily 100% passive.

For example. My EHB1005SMS has a passive blend knob. This results in a volume dip when it's centred in passive mode, but maintains equal volumes in active mode. Other active basses I've had have a buffer that is still engaged in passive mode that fixes this issue.