EMG 24v Conversion

[barebones]

Wanted to run this by some of you:

http://cgi.ebay.com/EMG-24V-MOD-KIT...&pt=UK_Guitar_Accessories&hash=item4cf092f20b

LOOKS like a cool idea. I've been running EMGs at 18v using two 9v batteries for years. This conversion would provide a little more headroom (EMGs can handle up to 27v) and take up less space. Space is a concern to me with these small bodied basses I'm building, so I'm definitely interested.

However, this guy's in the UK (I'm in the USA), and the setup doesn't look like it'd be very difficult to construct myself.

Can anyone advise me on how to put this together? Sources for these kinds of batteries? (Looks like something out of my cordless home phone.) Any factors I should be concerned about in employing this design?

Thanks!

 

[Burlington]

I'm confused. Do you recharge them or something?

 

[barebones]

I'm confused. Do you recharge them or something?

I don't know. I wondered the same myself, given the visual similarity to the phone batteries I mentioned. Price seems a bit low for rechargeables, though.

 

[MglMatador]

I fail to see the advantage to moving to that setup.

9V provides 4.5V of headroom either way, and 18V provides 9V of headroom. Most non-padded amp inputs can only accept up to line level signals in any case: anything hotter is going to clip the input stage. With 18V there is already 6 or 7V more headroom than what the amp can accept as an input.

 

[barebones]

I fail to see the advantage to moving to that setup.

9V provides 4.5V of headroom either way, and 18V provides 9V of headroom. Most non-padded amp inputs can only accept up to line level signals in any case: anything hotter is going to clip the input stage. With 18V there is already 6 or 7V more headroom than what the amp can accept as an input.

Not sure I'm following you here. EMG has generally said that running their systems at 18v does not increase output, only the headroom of the internal preamp housed in the pickup. This means you would clip that internal preamp later at 18v than with 9v.

In application, this seems to roughly translate to--at least this is my understanding, as well as what I have audibly heard--a player's ability to play with a heavier attack without getting unwanted clipping of the pickup's internal preamp.

Regarding the output to the amp, I would think to see increased clipping at an amp's input stage you would need significantly more output. My own experience with running my EMGs at 18v has shown little to no difference at the input stage of any amp I've used.

Lastly, the main advantage to me would be less space taken up in the control cavity. Otherwise, I'd just stick with two 9v batteries.

 

[line6man]

Aren't those rechargeable phone batteries that drain very quickly?

 

[Handyman]

I find it hard to believe that adding an extra 6v of headroom to a line level signal that's already powered at 18v, and designed to work down to 9V is going to do anything useful. Running electronics that close to their rated maximums is a bad idea in general.

Fresh or freshly recharged batteries often put out voltage SIGNIFICANTLY above their ratings. 24v is within 11% of the rated voltage. There's a very good chance you're going to get well over that after a charge.

 

[barebones]

I find it hard to believe that adding an extra 6v of headroom to a line level signal that's already powered at 18v, and designed to work down to 9V is going to do anything useful. Running electronics that close to their rated maximums is a bad idea in general.

Fresh or freshly recharged batteries often put out voltage SIGNIFICANTLY above their ratings. 24v is within 11% of the rated voltage. There's a very good chance you're going to get well over that after a charge.

Agreed on the headroom. Not the main reason to go with such a setup. 18v has always been plenty for me; I've never even tried the 27v setup EMG says their pups can handle. No need. I just like the idea of a battery smaller than 2 9v.

 

[PhatBasstard]

Not sure I'm following you here. EMG has generally said that running their systems at 18v does not increase output, only the headroom of the internal preamp housed in the pickup. This means you would clip that internal preamp later at 18v than with 9v.

In application, this seems to roughly translate to--at least this is my understanding, as well as what I have audibly heard--a player's ability to play with a heavier attack without getting unwanted clipping of the pickup's internal preamp.

Regarding the output to the amp, I would think to see increased clipping at an amp's input stage you would need significantly more output. My own experience with running my EMGs at 18v has shown little to no difference at the input stage of any amp I've used.

Lastly, the main advantage to me would be less space taken up in the control cavity. Otherwise, I'd just stick with two 9v batteries.

Yes. I've changed all my EMG equiped basses (Mostly Spectors) from 9 to 18 volts throughout the years.
It does not increase the output from the bass.

Now, from the "FWIW" dept:
I've known several guys who've tried the 27 volt mod on their EMG equiped basses. While the 9 volt to 18 volt upgrade is a noticable improvement for most of us, I haven't heard one person ever say that there was any difference noticable from 18 to 27.
However, I can understand the battery issue.

 

[walterw]

Now, from the "FWIW" dept:
I've known several guys who've tried the 27 volt mod on their EMG equiped basses. While the 9 volt to 18 volt upgrade is a noticable improvement for most of us, I haven't heard one person ever say that there was any difference noticable from 18 to 27.

+1

18v is a must for EMG bass stuff, but 27v (as well as 24v most likely), makes little difference in the sound while pushing the circuitry to the wall, wearing it out.

 

[Iridescentone]

Does look like a cool space saving idea.

At ten bucks, I'd imagine it's a throw-away deal, pop in a fresh one when needed.

The auction makes it appear that it's put out by EMG, though it doesn't seem to be on the EMG site.

Maybe email the seller?

 

[BFISHER1970]

This looks like a cool idea....
Or make your own for less than 3 bucks
2 A23 Energizers in series and a 9v battery harness.
Or if you want to get really crazy use 2 N-Type battery holders (an extra dollar) superglued together so you can pop the A23s out & replace them. Should still fit in a 9V compartment.

I think I'll make one today

 

[barebones]

This looks like a cool idea....
Or make your own for less than 3 bucks
2 A23 Energizers in series and a 9v battery harness.
Or if you want to get really crazy use 2 N-Type battery holders (an extra dollar) superglued together so you can pop the A23s out & replace them. Should still fit in a 9V compartment.

I think I'll make one today

Now this sounds like a cool idea. If you get around to making one I'd love to see it.

 

[MglMatador]

Not sure I'm following you here. EMG has generally said that running their systems at 18v does not increase output, only the headroom of the internal preamp housed in the pickup. This means you would clip that internal preamp later at 18v than with 9v.

Headroom is only important in the case where there is signal present of a magnitude in the vicinity of the voltage rails: you aren't going to be seeing any signals anywhere near 9V peak-to-peak in a bass, much less anything higher (like 18V or 24V). If you are, then you're applying too much gain in your preamp.

It's as if you placed a metal bar horizontally above you at 4.5 meters (14 feet). No matter how hard you jump, you'll never touch that bar. You can only hope to jump perhaps 1 meter into the air, and if you were 2 meters tall, you'd still be 1.5 meters away at the highest point. If you moved the bar up to 12 meters high, you still aren't anywhere near being able to touch that bar.

Lastly, the main advantage to me would be less space taken up in the control cavity. Otherwise, I'd just stick with two 9v batteries.

This seems like a cool idea. Is the route for the batteries tight in your bass?

I would also wonder what the maH spec if for those cells, as that will determine how long they last.

 

[Silent Fly]

There is something I never understood regarding the 9V vs 18V issue with EMG pickups.

18V power supply does not change the output volume – which make sense.

However, 18V power supply increases the headroom. In other words it increases the threshold where the internal circuit of the pickup clips.

Does this mean that if the pickups are powered at 9V they clip? Because if they don’t, there should be no point in using 18V power supply.

 

[SGD Lutherie]

There is something I never understood regarding the 9V vs 18V issue with EMG pickups.

18V power supply does not change the output volume – which make sense.

However, 18V power supply increases the headroom. In other words it increases the threshold where the internal circuit of the pickup clips.

Does this mean that if the pickups are powered at 9V they clip? Because if they don’t, there should be no point in using 18V power supply.

No, they don't clip since they are producing the signal and the pickup doesn't seem to be able to clip the preamp.

What does happen is you don't have as dynamic range. They sound more compressed on 9V. I like that better for their guitar pickups, but the bass pickups sound better at 18V.

 

[PhatBasstard]

What does happen is you don't have as dynamic range. They sound more compressed on 9V. I like that better for their guitar pickups, but the bass pickups sound better at 18V.

This absolutely nails it.
There is an openness that happens from 9 to 18 volts.
It's not a huge difference, but the first time I tried it (many years ago) it made me wonder why it took me so long to do it.
[Squidward]"All the wasted years..."[/Squidward]