Active or Passive

[warwickhunt]

39 minutes ago, NancyJohnson said:

 

Go and watch the video from the Bash. 

 

 

I did a 'blind' test re 10" 12" 15" speaker cabs(and multiples of) and posted my recordings on BC asking for educated guesses on which was which and nobody was able to correctly identify which was which.  Not a criticism at all but a lot of folk will make sweeping statements about speaker dimensions and tone!  

[NickA]

1 hour ago, fleabag said:

Nope.  Just pull the active / passive knob

which on my Dolphin just turns off the EQ which is the same as putting the tone knobs to 0.  Still needs a battery as the pickups are active.  Never seen the point really.

[tauzero]

2 hours ago, fleabag said:

Nope.  Just pull the active / passive knob

 

Pulling my knob wouldn't help on my Ibanez EHB1265MS, or my Sei Jazz - but the toggle switch would.

[crazycloud]

6 hours ago, tauzero said:

Pulling my knob wouldn't help

WRT instrument tonalities, there's a considerable amount of knob pulling.

[crazycloud]

7 hours ago, warwickhunt said:

 

I did a 'blind' test re 10" 12" 15" speaker cabs(and multiples of) and posted my recordings on BC asking for educated guesses on which was which and nobody was able to correctly identify which was which.  Not a criticism at all but a lot of folk will make sweeping statements about speaker dimensions and tone!  

Having done a substantial amount of DBT/ABX testing of audio gear, I'm not surprised at all. And speakers being transducers, are far less linear than the majority of amplifiers.

[NancyJohnson]

 

 

 

Edited November 27 by NancyJohnson

[Stub Mandrel]

29 minutes ago, NancyJohnson said:

 

 

 

 

Blind Bass Tony was a little known blues artist from downtown Chicago in the 1930s and 40s.

 

[Woodinblack]

On 25/11/2024 at 21:25, SimonK said:

 demonstrates why active pickups were created in the first place - precisely so that you could control EQ better on the bass itself!

 

No, active pickups were created so that you could use a smaller magnetic field which would have less drag on the strings, giving you a more pure sound of what the strings were doing, but doing that creates less power from the pickup so you amplify it to bring it up to the output level of a normal pickup with a strong magnet.

active preamp (on passive pickups, like most basses) was made so that you could control the output impedance of the bass, without the output and frequency response of the bass being governed by the output cable and whatever you plugged into, to give it more consistency between amps / effects. As a side effect you could then also control EQ better, but that wasn't the point.

 

Ultimately all basses are active if you plug them in, it just depends if you want the amplifier before or after the jack cable.

[Stub Mandrel]

10 minutes ago, Woodinblack said:

Ultimately all basses are active if you plug them in, it just depends if you want the amplifier before or after the jack cable.

 

Very much this.

 

Though one potential advantage is with twin pickup basses - being able to mix them onboard without the crosstalk of passive mixing. Although that interaction is part of the sound of some basses and not all onboard preamps used with passive pickups do this.

 

 

Edit: SOME but not all actives (e.g. my Hohner Jack with EMG licenced pups) have a weak passive signal due to low impedance pups. My Sire seems to have a better passive signal but still not as hot as a typical P. This means the active/passive comparison for an individual bass doesn't always equate to comparing two active/passive basses of similar configuration.

Edited November 27 by Stub Mandrel

[Woodinblack]

4 minutes ago, Stub Mandrel said:

 

Very much this.

 

Though one potential advantage is with twin pickup basses - being able to mix them onboard without the crosstalk of passive mixing. Although that interaction is part of the sound of some basses and not all onboard preamps used with passive pickups do this.

 

Indeed - makes other things possible too, I was surprised that Leo never brought the stacked volume/tone per pickup thing back on the jazz with an active pickup, most of the early work with pre-amps was him anyway

 

But I suppose quite a few people like the pickup mixing on a jazz where turning both pickups full takes the highs out of the signal

 

[Steve Browning]

I have two basses that are active. The OLP Stingray that was converted to pre-EB spec and my fretless Precision. That's actually a passive Lace Sensor with a piezo in the bridge. I installed a buffer to bring the piezo output down to the LS level.

 

I only use the fretless on gigs and have a Mike Hill switcher that has a level control on one channel so I can balance the outputs to the amp. In terms of eq, I use the eq on the fretless  to get the tone, keeping the amp eq the same for both this bass and the SVLs that I play for the majority of the set.

[fleabag]

12 hours ago, NickA said:

which on my Dolphin just turns off the EQ which is the same as putting the tone knobs to 0.  Still needs a battery as the pickups are active.  Never seen the point really.

 

Yup, my passive turns off active EQ, but the passive knob has its own EQ ,  and no battery needed.

[NickA]

I'm going to stop posting on this thread.  I just agree with everything @Woodinblack says. 😂😂👍

[ped]

5 hours ago, NancyJohnson said:

 

 

 

 

I didn't know the basses in the test beforehand but I was able to identify the J, P, MM, Spector, Tbird. I mistook the Rick for a Jazz. I really think the differences are clear. It was definitely easier to recognise them with fresh strings.

[tauzero]

6 hours ago, Stub Mandrel said:

 

Though one potential advantage is with twin pickup basses - being able to mix them onboard without the crosstalk of passive mixing. Although that interaction is part of the sound of some basses and not all onboard preamps used with passive pickups do this.

 

I'm not sure that any of my active basses with passive pickups (all of them except the Warwicks) have buffers prior to the blend. My Sei Original did originally (see what I did there?) have a Bartolini preamp that buffered the pickups prior to the blend, but it went titsup so got replaced by a Delano that doesn't.

[itu]

6 hours ago, tauzero said:

I'm not sure that any of my active basses with passive pickups (all of them except the Warwicks) have buffers prior to the blend.

True. There only few preamps that mix pickups: John East, EMG, Audere. Noll Mixpot is an active mixing component. Most of the other systems use simple blend pot which loads both pickups, and cuts high end.

 

pickups - blend - vol - tone stack - output

 

As I have said countless times, any part of this signal path can use battery powered buffers producing lo-Z ("active") signal. But any does not mean that every part is lo-Z.

 

@Woodinblack wrote:

"...active pickups were created so that you could use a smaller magnetic field which would have less drag on the strings, giving you a more pure sound of what the strings were doing..."

 

The main point is, that with lower inductance (less windings in the coil, and weaker magnet) you get wider frequency response. Very high output pickups have stronger magnets, more wire, and narrow f response.

 

@Woodinblack:
"...active preamp (on passive pickups, like most basses) was made so that you could control the output impedance of the bass..."

 

I think you are partially on the right track here. Yes, lo-Z output is good while transferring signal through the cable. If Z and noise were the most important things, we would have balanced line outputs in our basses. But I have seen just few balanced output systems in basses, like in Wal, Sei and Vigier.

 

Alembic did quite many trials with preamps during 70's (they weren't the first, but very visible). As they used very low impedance (power hungry and high quality) opamps (NE5532/4 family) they needed external PSUs. I do think their main goal was to make a functional preamp with powerful tone tweaking options. On top of that the result had a lo-Z output.

[NickA]

Wals don't merely buffer each pickup, they buffer each hum cancelling coil pair (which I think are wired in series); then filter the total from each pickup and only then mix them. The 4-string pickups have a total of 5 cables coming out of them which go to a summation circuit who's imput impedance is matched to the pickup output impedance to achieve a particular frequency response .... you can't do that on a passive bass!!

 

They have balanced DI outputs too, but as those are fed via a transformer, I doubt the output impedance is as low as using the jack socket - it's just balanced to allow grounding of the output at the mixing desk I guess. Never used it. 

 

I was going to shut up about this .. but it's been an obsession over the years leading to my own active circuit designs ... eventually abandoned because John East and Electric Wood do it better than I could!  The final iteration of my own design did have an active / passive switch and the difference between the active sound and the true passive sound was so marked that I had guitarists asking me to make their guitars active "to get that clarity".. in the case of a vintage Burns guitar, I refused to mess with it, but put the active electronics in a little stomp box for him instead.