Active vs Passive PUPs Log Out | Topics | Search
Moderators | Register | Edit Profile

Alembic Club » Miscellaneous » Archive through December 12, 2010 » Active vs Passive PUPs « Previous Next »

Author Message
mike1762
Senior Member
Username: mike1762

Post Number: 696
Registered: 1-2008
Posted on Sunday, December 05, 2010 - 5:45 pm:   Edit Post

I asked this question at a different site but never got an answer, so I'll try here!!! Isn't the only difference between an Active PUP and a Passive PUP the fact that an Active PUP has a preamp incorporated into the PUP housing? For example: both Alembic and Music Man have "Active" electronics by virtue of an on-board pre-amp, but the PUPs themselves are Passive. I just bought a bass that is loaded with EMG HZs (a Passive PUP) hooked-up to an on-board 18V 3 band EQ. I read some reviews where the vendor was criticized for using Passive PUPs with Active electronics. Did they miss the point or do I misunderstand something?
crobbins
Senior Member
Username: crobbins

Post Number: 743
Registered: 6-2004
Posted on Sunday, December 05, 2010 - 10:15 pm:   Edit Post

http://alembic.com/club/messages/449/83563.html?1280979778
bigredbass
Senior Member
Username: bigredbass

Post Number: 1566
Registered: 9-2002
Posted on Sunday, December 05, 2010 - 11:48 pm:   Edit Post

The active EMGs have fewer turns of wire in the coil, their original designs actually including a preamp in the shell. These fewer turns result in a low enough output to require this powered (from the 9- or 18-volt battery assembly) setup to present a strong enough signal to the preamp section of your amp. These can then be run thru EMG's BTS/BTC networks or any of their accessory tone modifiers built into the bass.

The HZ EMG's can be wired up with regular pots if need be and run exactly like 'regular' Fender or Gibson pickups. They can also be run into 9- or 18-volt tone networks as well, and this is where you see the 'passive pickup/active electronics' setup you're talking about.

The real difference in the real world (tone preferences aside) is that the HZ pickups obviously have enough turns of wire to make enough output on their own, but they can potentially be noisier because of that, and that noise will be amplified by the add-on active tone network. In my experience, the true active EMGs are deathly quiet. And they are internally grounded: This eliminates that ground wire back to the bridge you'll need with HZ pickups, largely increasing the chance of getting bit by the mic if your grounds are all over the place in a crummy electrical environment ! Also, since the preamp is shielded in the shell, I've owned very quiet EMG basses that had no shielding in the control cavity at all, a truly strange sight. You could never do that with passive pickups.

If you're familiar with mics, think of it this way: High impedance picups are like so-called 'dynamic' mics; low impedance pickups are phantom-powered, just like that kind of mic, whether it's the 1 or 2 9v batteries, or the rack-mount power supply of the Alembic Series axes.

Or think of it this way: You COULD run EMG low impedance pickups and the high impedance ones with a preamp in the shell. You could NOT do the same thing without preamps.

And bear in mind, the use of the terms 'low' or 'high' impedance, or 'active' or 'passive' is very loose. I only used EMG as an example as I've a lot of experience with them. Other brands would require some homework for me to give you a proper answer.

J o e y
mike1762
Senior Member
Username: mike1762

Post Number: 697
Registered: 1-2008
Posted on Monday, December 06, 2010 - 2:39 am:   Edit Post

Ok... I get the High/Low impedance thing. Using my example again: both Alembic and Music Man have "Active" electronics by virtue of an on-board pre-amp, but the PUPs themselves are Passive (Alembic PUPs are Low impedance and MM PUPs are High impedance). PUPs might be referred to as Active either because they are Low impedance and/or have an incorporated pre-amp. Is that a correct statement?

So in the case of my instrument: I have an on-board pre-amp (thus it is "Active"), so I can continue to use the High impedance HZs or I COULD exchange them with a pair of Low impedance PUPs. But I WOULDN'T want to use anything that had an "incorporated" pre-amp (since I already have the "active" circuitry external to the PUP)???
bigredbass
Senior Member
Username: bigredbass

Post Number: 1568
Registered: 9-2002
Posted on Monday, December 06, 2010 - 10:04 pm:   Edit Post

Maybe . . . what brand pickup(s) and preamp / tone network are you using?

J o e y
mike1762
Senior Member
Username: mike1762

Post Number: 698
Registered: 1-2008
Posted on Tuesday, December 07, 2010 - 3:30 am:   Edit Post

The bass hasn't even been delivered yet, but its a fretless Schecter Stilleto Studio-5. I had a chance to play the fretted version and was pretty impressed by the features offered at the price point (35" Neck-through with Maple/Walnut, Rosewood FB, Mahogany body, Bubinga top). The electronics are a pair of EMG HZs (never used them before) with an EMG 18V 3 band EQ.

What got me off on all this was some user reviews regarding the PUP/preamp combination. Several people said they were going to change out the Passive PUPs for Active PUPs... I got to thinking about that and started wondering "What is an active PUP?". EMG isn't helping matters because they actually market some of their PUPs as "Active". However, those PUPs are sold WITH the preamp: so they are referring to the electronics as a whole... not just the PUP (it's not clear whether those PUPs are low impedance). I guess the advantage of using active electronics with high impedance PUPs is the tone shaping ability that you wouldn't have with passive electronics (but as you say, it can add noise).
bigredbass
Senior Member
Username: bigredbass

Post Number: 1569
Registered: 9-2002
Posted on Tuesday, December 07, 2010 - 9:15 am:   Edit Post

I've played one of those and I think you'll be fine as is. However, EMG does quite a bit of OEM sales to various builders (their website has a page for OEM only). I'd play it, see what you think. I'd believe IF you want something different, you may luck out inasmuch as EMG probably makes low impedance versions in the same shell size that would drop-in and work with the electronics already installed. I came close to buying an EMG-loaded bass with these size shells, and had already decided to swap out the J-based neck pickup for a P-loaded replacement.

And yes, the current norm is the three band EQ built onboard the bass. This is fashion now, and with all that EQ plus the ton of EQ most bass amps run these days, it's a quick recipe for mud ! REALLY makes me want a filter and three knobs on an F2B !

Anyway, you could certainly call EMG and they could advise.

See what I mean? Lots of people sling these terms around in a really confusing manner !

J o e y
mike1762
Senior Member
Username: mike1762

Post Number: 699
Registered: 1-2008
Posted on Tuesday, December 07, 2010 - 1:53 pm:   Edit Post

You're right... my Carvin has high impedance PUPs with active electronics, but I find myself running it passive most of the time.
funkyjazzjunky
Senior Member
Username: funkyjazzjunky

Post Number: 652
Registered: 5-2007
Posted on Wednesday, December 08, 2010 - 12:12 pm:   Edit Post

Mike,

I also play my Carvin basses in passive mode.

Topics | Last Day | Last Week | Tree View | Search | Help/Instructions | Program Credits Administration