Battery Drain with Active P'ups Forgetting to unplug

[MoireBass]

You could have a pedal switch the preamp on and off in any active bass. The cable between bass and pedal would need TRS connectors and be made of balanced mic cable instead of unbalanced instrument cable.

If connected to a power supply, on power-on the pedal would 1) wait a fraction of a second to allow its own power supply to settle, 2) activate a relay that connects the input connector ring to ground, turning on the preamp in the bass, 3) wait 1-2 seconds (so as not to get a very loud pop in the signal), 4) activate a second relay that unmutes the bass signal.

On power-down, it would have to 1) have enough stored power to finish, 2) detect the power-down state and release the second relay to mute the bass signal, 3) wait ¼-½ second, 4) release the first relay, disconnecting the ring contact from the ground to turn off the preamp in the bass.
You could also use a switch on the pedal and bypass both steps 1) above. Easy peazy, probably less than $35 worth of parts.

Don't know what you'd search for on Amazon to see if someone's already done it. It'd be a niche product.

 

[kgbeast]

You could have a pedal switch the preamp on and off in any active bass. The cable between bass and pedal would need TRS connectors and be made of balanced mic cable instead of unbalanced instrument cable.

If connected to a power supply, on power-on the pedal would 1) wait a fraction of a second to allow its own power supply to settle, 2) activate a relay that connects the input connector ring to ground, turning on the preamp in the bass, 3) wait 1-2 seconds (so as not to get a very loud pop in the signal), 4) activate a second relay that unmutes the bass signal.

On power-down, it would have to 1) have enough stored power to finish, 2) detect the power-down state and release the second relay to mute the bass signal, 3) wait ¼-½ second, 4) release the first relay, disconnecting the ring contact from the ground to turn off the preamp in the bass.
You could also use a switch on the pedal and bypass both steps 1) above. Easy peazy, probably less than $35 worth of parts.

Don't know what you'd search for on Amazon to see if someone's already done it. It'd be a niche product.

I have a version of it with two LEDs. One indicates that the thing is on, another turned off when voltage drops lover than 8V. No relays though. Pop is not too bad in my case.

I do not use it as I stopped worrying about it since I started using rechargeable batteries

Being inspired by this thread, I want to add a feature so the bass is powered by a power supply.
Probably will be to noisy... But will try once I get back home from my work trip.

 

[johnh89]

Great ideas all . But it is really a lot easier just to unplug the bass . A solution with no problem ?

 

[Snert]

Probably will be to noisy

Why? Plenty of pedals are used with very modest, in terms of design, linear or SMPS, to record with or play live, so why would it present a problem with an external PS with active PUs? Alembic have been using a very poor design with their Series basses for decades and it presents no issue for most users.

Great ideas all . But it is really a lot easier just to unplug the bass . A solution with no problem ?

Where is the angsty victimhood in that?

 

[PWolverine]

I never understood the complaint about unplugging your guitar after using it - especially with active electronics.
All my previous guitars in the past were passive, and my most recent (and currently only) bass is an active Fender that I use at home. It is just one of those things that you need to develop a habit of unplugging the bass when you are done. My first set of batteries that came with the bass lasted me about 8 or so months of use, with forgetting to unplug it about 5 times from memory, so it was left on over night until I used it again the next day. Second set of batteries I changed after about 10-11 months, just because I figured it would be going down a bit, but no noticeable difference in sound, unlike the first battery where I noticed I was upping volume and hearing distortion when it was near the end of its life - Active basses don't suddenly cut out too, they have a good amount of time where you will notice signs telling you that the batteries are getting low - Though that Batt-O-Meter mentioned earlier in the thread looks interesting.

We live in a world now where batteries are everywhere. They need charging or switching off after you use it has become common. It is no different (IMHO) to remembering to charge your mobile at night, or worrying about turning your lights off when you leave a car at night.

Fender's Manual says:

Typical battery life for both systems is approximately 600 hours of playing time.
All Fender basses with active preamps are equipped with switching jacks that engage the battery when a cable is plugged into the jack. To maximize battery life, unplug your cable from the bass when not playing the instrument.​

You get 600 or so hours, so technically you could possibly change your batteries every month (25 days) and just leave it plugged in, but I wouldn't want that extra expense personally and figure it is just as easy to remember to unplug your bass when you put it in its stand, or wherever you keep it. After a while it becomes second nature and you just do it, finish playing = unplugging bass and putting it wherever you keep it.

If that is too hard, just spend the extra money on bulk batteries and change them at the beginning of every month and leave your guitar plugged in, because if that is the convenience you want, that is the price you will have to pay - or get a passive bass.

 

[Deleted member 368008]

Why? Plenty of pedals are used with very modest, in terms of design, linear or SMPS, to record with or play live, so why would it present a problem with an external PS with active PUs? Alembic have been using a very poor design with their Series basses for decades and it presents no issue for most users.

Where is the angsty victimhood in that?

EMG already has one but had this to say about external power for driving active pickups:

Invalid Link Removed

"Using an AC Adapter (power supply):
Using an AC Adapter is not a great idea. They tend to be noisy. EMG has yet to spec or design an AC Adapter. Effects pedals tend to be noisy because they usually adds a lot of gain. Since the pickup is the first element of the chain it’s best for it to have as quiet a power supply as possible, thus a battery.
If you can tolerate the extra noise from an adapter the choice is yours"

Which then defies the whole purpose of having any active pickups at all in the first place, because the incentive is just that, to have virtually noiseless and hum free with large noise headroom.

Alembic though, is just that, doesn't work without that external supply. And their basses costs a fortune or two. I heard that their customer base is declining, and have less and less sales. Poor design for that price? Not developed anything else since 1969? Well, they had it coming.

EMGs box above is recommended to be driven by batteries, although it has the option for running it with an adapter, which they in turn do not recommend. Which - actually - is a first to me.

Only one bass throughout the history I do recommend having external supply: The Peavey Cirrus. It eats batteries for breakfast, lunch and dinner.

- - - - - - - - - -

48 hours battery time? You must be kiddin'... here's the lowdown of EMG:

From EMG site (horses mouth):
The typical EMG Pickup requires about 80 Micro-amps of current. For a battery rated at 500 MilliAmp Hours it translates like this:
1 MilliAmp = 1000 MicroAmps
1000 MicroAmps / 80 MicroAmps = 12.5 times
12.5 * 500maH = 6250 maH
6250 / 2 (battery cutoff voltage 4.2V) = 3125 Hours per pickup
The Lithium Cell will usually deliver about twice as many hours as the Alkaline cell, but the cost is higher.

Thus: 3125x2 = 6250 hours. One 9 volt lithium cell battery. Ok, let's install another one and get.. yes you guessed it right..paralell wiring connection:

6250x2 = 12500 hours

Mind you that EMG works down to 4,5 V before they starts to choke and crack in the sound, and at 4,2 v they just stop and goes dead silent. Let that sink in, as Elon Musk said.

12.500 hours = 1,4 years of constantly plugged in or playing. 24/7. Is probably longer than I've ever played bass...

I didn't even blame myself for forgetting any cable in for a weekend or overnight. Or on stage, studio, a week til next rehearsal time...

But people yet have the nerve to bitch and bicker about battery changes on, yes, EMG pickups too.

Beats me.

 

[Deleted member 368008]

Conclusion is thus: If you do have a bad habit that you can't get rid of, run EMG active pickups instead, and lithium cell batteries, then the system will not care that much if you forgot the cable plugged in once in a while, or even ever so often. The additional battery drain, will be so subtle that it is neglible.

Still try - though - to break that bad habit, by unplugging as often as you can, anyway. Or at least: try to! Reminder on your cell phone each 5 minutes?

 

[mcnach]

Passive or active, I just don't like leaving a cable attached to a bass where if I trip I can bring it crashing down or damage the socket or both. It's not a question of 'if' but 'when', at least for me: time and time again I've been shown that if something can go wrong around me, one day it will.

At home, I've got a rack with a few basses and guitars ready to use, amplifier next to me, and a cable hanging from it, unplugged. I can't imagine being so busy that those extra 5 seconds would mean anything to me.

:shrug:

 

[kgbeast]

Only one bass throughout the history I do recommend having external supply: The Peavey Cirrus. It eats batteries for breakfast, lunch and dinner.

Cirrus pickup, VFL, on its own draws 175uA so 80uA of the EMG pickups is not exactly a marvel of engineering. MEC J-ACT for example pulls 38uA. That said, VFL is a lot louder than J-ACT so perhaps the extra power is not wasted as being able to keep the gain on the amp down, would be less noise.
Perhaps some consume even more than VFL and some consume less than J-ACT, but I agree that on average a passive bass with an active pickup or two should last many thousands of hours and unplugging such bass is not going to save anyone any serious dosh.
However when it comes to the bass with a preamp, there to each its own. Yes Cirrus pulls 5mA and that makes it two 9V last less than 200 hours. In my test I think I got 120 hours some time ago.
As I recommended previously, measure consumption of you bass so you can then judge if you better off unplugging or not. And once again, if you use rechargeable batteries, this becomes a no conversation even if your bass lasts only 48 hours on a battery. It takes only an hour or two to charge one from 0.

 

[fig]

So last night I took a hard look at adding a method, or simple circuit, to turn the battery on or off without the 'pop' and stopping battery drain (instead of unplugging the cord).

Our preamp problem is that the output jack is still connected while battery/preamp voltages and currents are still actively stabilizing. This results in the 'pop'.

Our main instruments amps and home theater amps have a time delay before the power amp signal is applied to the output connectors. The delay gives time for the sudden inrush of currents and voltage stabilizations to happen. Shortly after turning power on, a relay kicks in connecting the now stabilized amp signal path to the output connectors.

Same delay of final output can be done manually, it seems, with a 2P2T, 3 position, On/On/On switch. It turns your battery on or off (no battery drain when OFF selected while plug is inserted) and delays the output jack from connecting so there's no 'popping' when battery gets connected or disconnected by the switch.

-Stops battery drain (when selected OFF) with cord plugged in.
-Adds Mute function with toggle in middle (Battery(s) still on, output muted).

So for operating the switch to give adequate delay, momentarily pause in the middle position (maybe a second). This gives currents and voltages time to stabilize.

I haven't tested it, 'cause I only thought of it last night. And I don't have the switch on-hand to try.

Anyway, if some experienced folk could look at this and see if I haven't overlooked something obvious. 'Cause it scares me that this was such a simple solution that I probably did overlook something obvious LOL.

Forgot to add that the controls (volume(s), tone, pickup selector, etc) can be before the preamp (as shown), on the preamp, or after the preamp.

 

[Jerry Catanescu]

I use a power-on/low battery indicator LED that flashes briefly about once per second or so when the bass is on and the battery is good. The flashing catches the eye much better, and also consumes much less power, than a solid light. You can make your own if you want, I posted the schematic on my site. I won't post the link here to avoid triggering the overactive mods. I don't even sell it anymore BTW.

Gotta love this forum. Instead of contributing a solution, many posters basically try to talk the OP out of the way he prefers to use his own bass. It's OK to say nothing if you have nothing constructive. Do you also unplug your TV when not in use? How about the nightstand lamp? You know, to avoid tripping over the wire at night

I, for one, have always felt that having to unplug the bass to power it off makes for a very clumsy on/off switch.

 

[fig]

MY APOLOGIES. I made a big boo-boo my diagram in post ##130.

This regards the OFF and MUTE sections, I didn't ground the jack tip when it's disconnected from signal path. It would pick up noise by not being grounded.

Updated the switch contacts (4,5,6) to Jack tip. All else the same. Here's the new version.:

This On/Off switch (Mute was an unavoidable accident) is in response to the many folk over many years that have asked about installing a switch to turn the preamp off which keeps the battery from draining while cable is still plugged in.

 

[Deleted member 368008]

So then, what's the difference in forgetting? Forgetting to flip a switch or forgetting to unplug? Which is the actual "switch" in the end, although it looks like a plug. Why must it look like a switch?

Isn't it easier to accidentally knock the switch in/out without knowing it and it's on again, and draining the batteries even if it's unplugged? You can see from very far away if a cable/plug is unplugged, but not that much with a switch...

 

[Deleted member 368008]

Again remember:

EMG + 2 9v in pararell, and lithium batteries = 9 years before I had to change them out the first time.

I did unplug it more often though, than I forgot to, but still, in the rehearsal space the bass was in the stand, plugged in a whole week, and when I came back I sort of grumpily scolded myself, and made sure I unplugged.
I e occasionally forgetting to unplug, didn't get noticed that much or at all in the battery draining department.

This type of configuration can be recommended, if the physical layout and the manner of which the battery compartment is accessed or opened is unwieldy or hidden beneath other things. Like inside a stratocasters pickguard, which you have to open rup completely, to change batteries. Remove strings. As unwieldy and cumbersome as it gets. If you're not that keen on routing out a place for it at the back.

My bass did have a dedicated compartment so it was not a big deal at all. Didn't need screwdrivers even...or hex.

 

[Deleted member 368008]

Instead of contributing a solution, many posters basically try to talk the OP out of the way he prefers to use his own bass. It's OK to say nothing if you have nothing constructive. Do you also unplug your TV when not in use? How about the nightstand lamp? You know, to avoid tripping over the wire at night

Well, the OP asked not for a solution, but if his solution would help. It was then answered in the first reply: No it would not help. He didn't need a solution, he already had one, that he figured out himself. He only asked if his solution (or idea) would help. Here's what he really wrote verbatim:

Anyway, concerns about my memory aside, would it actually stop the draw on the battery? My brain says it would NOT because contact is still made but I have little knowledge of these things. Pic for attention.

As far as I am concerned we answered his question. And provided alternatives, and explanation WHY it would not help him at all. I find this peculiar, back in the old days when pedals where run by batteries only, no one complained about unplugging the input jack to them, for saving the battery. Beats me. If he stated he have little knowledge about these things, we provide him with more knowledge. Simple as that.

Yes, I unplug my TV every time a thunderstorm passes over, which is does here in Sweden every 4th lap year or something. Very very rarely, once in a blue moon. But more often, like when the electricity prices went bezerk last winter to save that small idle current for standby mode, which I did on every unit I had. I even disconnected my freezer.

 

[Deleted member 368008]

FWIW: That bass with EMG and 9 years batterylife, has now been replaced with passives (Lundgrens). I do still unplug it. And will continue to do that. As I do with all other instruments, too, passive or active.

 

[sissy kathy]

I have to wonder how hard it would be to design a little onboard gadget that says "if there's been no signal for x minutes, cut the power"...

I have actually bought something similar for flashlights. They are just a motion detector so they work on motion rather than a signal. So if you set the bass on your stand and walk away it would turn off in a couple minutes; and when you pick it up the movement is detected and the bass would be on before you could get the strap over your head. The device is about 33mm (1 3/8 inch) in diameter with a thickness of <3mm (1/16 inch).

I've reached out to the seller to discover if they are still available and can be adapted for this purpose.

 

[Snert]

^^ And if the motion detect circuit simply applies power once motion is detected, there will almost certainly be a thump as the audio circuit powers up.

 

[sissy kathy]

^^ And if the motion detect circuit simply applies power once motion is detected, there will almost certainly be a thump as the audio circuit powers up.

I'd assume the amp gets powered down, or is everyone that forgetful. If you're worried about the thump then go ahead and keep using up your batteries.

 

[Snert]

I'd assume the amp gets powered down

I've done enough live gigs, both as a player and running the FOH, that making an assumption like that is bound to get downstream gear damaged sooner rather than later.