9v vs. 18v- worth it?

[cloren]

my answer is: yes!

I've not had to change batteries since I got my lecompte 3 months ago and I'm plugging in every day.

I also hear you get more 'headroom' with a 18v preamp- i think i get what this means with an amp,

but how does having more headroom with your preamp affect sound/output/etc?

 

[Altitude]

how does having more headroom with your preamp affect sound/output/etc?

All else constant, a preamp with more headroom will pass a higher-level signal without clipping than one with less headroom.

 

[themarshall]

IIRC, series = 18v & more headroom, Parallel = 9v but longer battery life.

 

[Philbiker]

More headroom means more chance of overdriving the input stage of your amp. My 9v Brice V2 with active pickups is the hottest output bass I've ever experienced. It's ridiculous. The 18v preamp on my Axcelerator 6 never needs batteries.

 

[SGD Lutherie]

More headroom means more chance of overdriving the input stage of your amp.

No, more headroom does not equal more gain. I run an EMG BTC on 18V in my bass. If I bypass one battery it is not lower in output level, but tends to sound a bit more compressed. With the tone controls flat, it does not add gain to the signal.

Some circuits are designed to run on 9 volts, and 18 volts wont improve them, and some actually get noisier.

So the output level of the active circuit is not dependent on the power supply. Lower headroom will mean clipping if you try and get too much gain, but is fine running at lower gain. Likewise you can run a lower gain circuit on 18V and it will be more dynamic, but not necessarily louder.

 

[SamanthaCay]

i have a bartolini ntbt active pre-amp it will run off 9 or 18 volts when i first installed it i ran it on 9 volts and went through a battery about every six months than i switched to two 9 volts in series about 4 years ago and still have the same batteries in my bass i averege about two hours per day and have some times forgot and left it pluged in so i would say 18 is a good way to go and speaking of batteries has anyone tryed a litheum battery in there bass

 

[SGD Lutherie]

has anyone tryed a litheum battery in there bass

I used one in my bass for about a year. I only took it out because I changed the electronics.

They are expensive, but last a long time.

 

[ihateusernames]

I agree with David, especially on 9v sounding more compressed vs. 18v with EMG preamps.

 

[Munjibunga]

Hmph. I can't tell the difference in any real-life situation like, say, a gig. There are so many other factors that affect a bass's sound a lot more than whether the preamp is 9 or 18 volts.

 

[Altitude]

Hmph. I can't tell the difference in any real-life situation like, say, a gig. There are so many other factors that affect a bass's sound a lot more than whether the preamp is 9 or 18 volts.

+1

 

[scotch]

Hmph. I can't tell the difference in any real-life situation like, say, a gig. There are so many other factors that affect a bass's sound a lot more than whether the preamp is 9 or 18 volts.

+1. I cannot tell the difference (and my ears aren't that bad!)

Honestly, is an onboard preamp really able to take advantage of the full 9 volts (not to mention 18) anyway? It's not like there are light duty transformers or large value caps in a basses control cavity... (or are there?)

 

[Modern Growl]

there's no NEED for 18v. Top mfr's use 9v, ala Sadowsky, and his pre is one of the hottest, if not THE hottest in the industry.

i wouldn't go out of your way to have 18v... like routing your bass to fit the extra battery.

 

[scotch]

I understand that the extra voltage allows for greater headroom - but would an instrument level electric bass signal ever even approach such high voltage requirements? Even with an active bass shelving eq dimed at +12 dbu?

 

[ihateusernames]

yes munji, you are correct. and modern brings up a good point as well.

if it's quick and easy for you, try it. if not, don't bother!

 

[SGD Lutherie]

It all depends on the circuit used. Some of the early EMG pickups used a 1st generation FET op amps, such as the LF442. It's has relatively low power consumption for good battery life but barely enough drive for the recommended 10K load on them. So running them on 18V, and using a 100K pot instead of the 25K's they come with improves the tone (because the output impedance of EMG pickups is rather high, about 10K).

Also some op amps require a bi-polar power supply, that's where you have + and - voltage. So to get that from a single battery they have to split the power to +/- 4.5V. Running the circuit on 18V gives you +/- 9V.

Some discrete FET circuits are less noisy at 9V than 18V because that's what the circuit was biased for.

If I were going to design a preamp that used two 9 volt batteries, I'd rather make it a bipolar 9V circuit, instead of a single ended 18v circuit.

There are many preamps that work just fine on 9V.

 

[kb9wyz]

18V, definitely. I can't really quantify why. I think (good) 18V systems just sound clearer, more bass-like. I have heard what SGD mentioned above, and agree.

 

[Milothicus]

i used to have EMGs and ran them at 18v, just because i could...

my understanding is that the 18v won't affect your every day fingerstyle playing because the output of the pickups is fairly constant and well within the 9v headroom. it's just the real spikes, like if you're slapping and popping that could possibly be clipped, and use a bit more headroom.

 

[Tommy Preston]

PUt a 5.3ap Bart pre @ 18 volts in my SR506 and replaced the pups w/ real Barts also. It's too touchy ..clips ...just not too happy ...going back to 9 I think