Advantages of an 18V pre amp?

[Dubs]

What are the advantages of using an 18V pre amp over a 9V…or wiring your pre amp for 18V instead of 9V?

I’ve got a pre amp for the Jazz bass that I’m building and it can be run at either 9V or 18V. I’m probably going to wire it as a 9V cos my experience of 18V pre amps tends to be that the output is so high that it saturates the input of my effects leading to a really sh*t digital distortion kind of sound on a lot of my pedals, but I’ll experiment with a 9V and 18V configuration before I decide what I’ll stick with.

Any suggestions or tips as to why 18V would be advantageous over 9V?

Ta very much

[budget bassist]

More headroom? More boost on the volume and EQ = more range of sounds, though you can just turn the volume down if you don't want it distorting

My jazz has an 18V 3 band preamp, it's nowhere near as my 9V 2 band musicman preamp though, just a hell of a lot louder. (strangely enough my passive modded SUB is louder than my actuve.... ), if you've ever tried a bongo preamp though, phwoar! That has crazy amounts of boost on everything! So much power!! That said though, you wouldn't turn any of the controls all the way up, it just has a lot of headroom.

[stonecoldbass]

Don't really have an answer, but I like how my sadowsky came with a warning advising against turning both tone controls all the way up!
It's only a 9v circuit but has the hottest output of any bass I have, even more than the 18v circuit on my zoot.
c

[Dr.Dave]

I'm no sparky but I should think an 18v is more reliable. 2 batts are less likely to die a sudden death than one so there should always be more nosebag for the eq circuits to feed on. That's how it was explained to me anyway.

I have 3 batts on my Shuker - the 3rd powers the side LEDs. Good idea , so if I leave them on in the case for a week, like a numpty, I might lose my lights but my eq's not affected.

More batts also provides more opportunity to show off by sticking them on your tongue to see if they're working OK !!

[Jean-Luc Pickguard]

My 81 Precision has an EMG active pickup, but no actual eq/preamp. I have made a conversion clip to run it off 18v rather than the standard 9v. Unfortunately theres no room for two standard 9v batteries, so my clip uses the 1.5v cells from A23 12v batteries. There are eight 1.5v button cells if you open up an A23. Twelve of the cells fit perfectly onto an AAA holder.

It definitely sounds better, a lot more alive almost as if all the oomph was being compressed out of it with only 9v.

[Dubs]

[quote name='Dr.Dave' post='364072' date='Dec 27 2008, 10:17 AM']More batts also provides more opportunity to show off by sticking them on your tongue to see if they're working OK !![/quote]

- I’ve heard you can die by doing that? – something about the shock might stop your heart? Urban myth maybe?

[quote name='Jean-Luc Pickguard' post='364082' date='Dec 27 2008, 10:29 AM']My 81 Precision has an EMG active pickup, but no actual eq/preamp. I have made a conversion clip to run it off 18v rather than the standard 9v. Unfortunately theres no room for two standard 9v batteries, so my clip uses the 1.5v cells from A23 12v batteries. There are eight 1.5v button cells if you open up an A23. Twelve of the cells fit perfectly onto an AAA holder.[/quote]

Very ingenious


Are there any scientific reasons why 18V is ‘better’ than 9V?
EDIT: I should point out that I've used a couple of 18V pre amps in the past so I'm not a newb to them, just I don't get why they might be 'better' then 9V? My experience has been that they’re too hot to use with the majority of the effects that I use but they sound great when I’m going clean straight into my amp.

Edited December 27, 2008 by benwhiteuk

[warwickhunt]

I can't give you any of the 'science' behind why but if your circuit is designed to operate @ 18v then that is when you will be getting the best signal to noise ratio and you will be gaining more headroom. However... don't expect a massive (ie doubling) of output or suddenly to have a 'huge' change to your tone! I've run basses with 18v and 9v circuits and the difference isn't that staggering, though I will add that I'm talking about gigging rigs/situations, you may well notice a difference if recording using high-end gear. The 18v OB1 preamp that I have in my SSI fretless (Bart pups) is no higher/hotter output than any of the other 9v circuits that I have in other basses (nor was the 18v Audere that I had in an MEC equipped SSI) but the 9v/18v (voltage doubler circuit?) Tonepump Spector has a huge range on the tone controls; I have to run the Spector with the tone controls on 0/off to match my MEC equipped bass with bass and treble on 10/max.

Just some real life observations.

[Kiwi]

18v allows more headroom but this probably needs a bit of explanation. It's a bit like the difference in bandwidth between a 1mb connection and an 8mb connection and the difference all depends on what you want to do.

If you imagine you've got the vibrations of a plucked string on your PC as a graphic waveform a bit like this:



With a louder the note the peaks are at higher and lower extremes. For the attacky bits in a note, the sound would be relatively loud and show up as sharper peaks. A waveform for a series of plucked notes might look something like this:



What 18v does better than 9v is pass on the extremes of those attack peaks (also known as transients). The extreme peaks normally need a bit of extra oomph to get passed on which the 9v can't do. Transients can also ruin speaker cones and blow HF horn fuses if boosted too much. However in most live gigging situations the difference between 9v and 18v probably isn't going to be that noticeable to fingerstyle players. For people who slap or tap and want the attack of their playing to be passed on faithfully to the amp or PA, 18v might make things sound a little bit cleaner and crisper, especially in a recording situation. It also depends on the instrument, I'd imagine you'd be able to appreciate a 18v preamp a lot more easily in a Status Stealth than in a Gibson EB-3, just because the Status is a much more efficient instrument (although let me add not necessarily better sounding to everyone).

Jonas Hellborg had a 36v preamp in his signature Status bass because he wanted to pass on as much of the transients of his playing as possible. I think he has a similar number of batteries in his Abe Wechter acoustic and it also drove the development behind his Warwick line of amps. I guess this means that in a quiet setting you'll get more of the power, more of the intimacy of someone's playing if they're doing solo work, but I can't imagine anyone ever needing a 36v preamp or being able to appreciate the difference in transient attack when playing in a band.

Some of the EMG circuits (and IIRC the John East preamps) are capable of taking anywhere between 9 - 24v. It all depends on what you're going to use the bass for and what other gear you're planning to use. Its important to think of the bigger picture as well. Its all very well having a bass that is capable of making sweet jesus love to your ear drums but there's no point in plugging it into an amp that is designed for bog standard fender type basses. The benefits are unlikely to be passed on all the way to your speaker. (And speakers are yet another thing entirely that I'm sure AlexClaber will pick up on).

[Prosebass]

Excellent reply by Crazykiwi. As a "sparky" I would like to add that these sort of arguments are settled by men in white lab coats with very sensitive test equipment and not by bassists sat round trying each others kit.
What makes a much bigger difference is how you pluck the strings each time !.
Don't get bogged down in technical specifications, at the end of the day its the sound that matters irrespective of how its achieved.

[warwickhunt]

[quote name='Crazykiwi' post='364171' date='Dec 27 2008, 02:08 PM']Its all very well having a bass that is capable of making sweet jesus love to your ear drums but there's no point in plugging it into an amp that is designed for bog standard fender type basses. The benefits are unlikely to be passed on all the way to your speaker. (And speakers are yet another thing entirely that I'm sure AlexClaber will pick up on).[/quote]

Yep CK elaborated far better than I could have!

As pointed out the benefits would need to be weighed against what your needs/equipment justified. An average gigging bass player (not saying the OP is 'average ) would likely as not hear a bigger difference by changing strings (for new ones or different brands/gauges) rather than upgrading from 9v to 18v or to take it to the next logical step... if you have cr*ppy cables (speaker and instrument) then maybe it's worth looking at upgrading those elements first.

re. your OP - you stated that you can run either 9v or 18v and that you are concerned about overdriving/distorting your signal chain... tbh you'd need to suck it and see if you had the latter problem as some 9v circuits can be hotter than 18v (I had a MM that was RED hot 9v compared to my 18v Warwick) but if either works then you may as well go 18v as you may reap the benefits at a later date.

Don't forget as someone has already pointed out, you can turn the vol pot down on your bass a smidgen if it is too hot!

[Dubs]

Thanks for the replies guys; very informative. As WH said, I’ll just have to “suck it and see” and spend some time trying out a few different things and see how the 9V and 18V affects my signal chain.

The 18V OB2 in my SSI has an amazingly hot output compared to any other bass (9V and 18V) that I’ve ever used/owned, so I guess I was just taking my experience of this and making an assumption that an 18V pre amp is likely to have a hotter output than a 9V.

The SSI has an absolutely amazing clean sound (obviously completely objective) when bypassing any effects, but tends to sound a bit rough through any effects, and as I said before, this is down to the really hot output. I’ve turned the volume down and this helps with the problem but then it gives a slightly different quality to the clean sound of the bass which isn’t as good as when the volume pots are at “10”. I don’t want to make the compromise and run it at 9V cos it sounds so good at the moment, so I’ll probably just end up using it for clean stuff (which isn’t really an issue at all).

Anyway, I’m at least a month away from installing the pre amp into the Jazz bass (no routing has actually been done yet) so I’ve got some time for a bit more research and pondering, but ultimately I’ll just test it in a 9V and 18V configuration and see what’s what.

[warwickhunt]

Are you going bass>effects>amp or are the effects in the amps effects loop? You can get different results depending upon how you have your pedals in your set-up; if in the effects loop you may have a series/parallel set or a pad switch to attenuate, you might want to play with all of the permutations!

[Dubs]

[quote name='warwickhunt' post='364305' date='Dec 27 2008, 05:26 PM']Are you going bass>effects>amp or are the effects in the amps effects loop? You can get different results depending upon how you have your pedals in your set-up; if in the effects loop you may have a series/parallel set or a pad switch to attenuate, you might want to play with all of the permutations![/quote]

I didn’t even think about this – At the moment I’m going Bass>Effects>Amp, but I’ll trying some things out with the effect loop (I’ve never bothered with it in the past).

Thanks for reminding me that potentially alternative solutions to this problem exist

[johnnylager]

[quote name='benwhiteuk' post='364412' date='Dec 27 2008, 07:39 PM']Thanks for reminding me that potentially alternative solutions to this problem exist [/quote]
Could someone remind Tony f***ing Adams?

[BigAlonBass]

[quote name='benwhiteuk' post='364104' date='Dec 27 2008, 11:28 AM'] - I’ve heard you can die by doing that? – something about the shock might stop your heart? Urban myth maybe?[/quote]

Nope, not an Urban Myth. Quoting Official N.H.S. statistics - An average of Nine people die every year in the U.K. from testing a PP3 with their tongue. Apparently, it's a fool-proof way of finding out if you were born with a weak heart. Thank goodness I wasn't. I'd been doing this for years before I read the article.

[bass_ferret]

It depends how you use it. As others have said, its a combination of pup output and pre-amp that creates the signal, and hot passive pups can be louder with not hot pups and an 18v pre-amp. There are ways to deal with this, use a bit of restraint on the controls and turn the volume down when you turn the EQ up, or stick a compressor on the front of your effects chain to stop the hot output overdriving them. I am sure there are other options. Lots of people use the EQ and volume turned up full all the time but that just means they have to turn the amp down.

[Mr. Foxen]

[quote name='BigAlonBass' post='369653' date='Jan 3 2009, 11:17 PM']Nope, not an Urban Myth. Quoting Official N.H.S. statistics - An average of Nine people die every year in the U.K. from testing a PP3 with their tongue. Apparently, it's a fool-proof way of finding out if you were born with a weak heart. Thank goodness I wasn't. I'd been doing this for years before I read the article. [/quote]

Got a citation there? Considering the current flows through the space between the terminals, your heart is far from any current. Google find me nothing but similar perpetuations of what is likely an urban myth with no references other than a doctor stating the shock might kill you or disrupt a pacemaker. And that Doctor apparently doesn't exist, or at least they spelt his name wrong, there is a 'Dr Xiheng Hu' at the department, who I'm about to email.

[Ou7shined]

When I wired up my custom 4 string J with EMGs and an OPB3 I rigged it so that I can bop back n forth between 9v and 18v at the flick of a switch. I also wired it so that the PP3s are parallel at 9v so that each battery drains equally and presumably twice as slowly. There is a difference in sound but it is almost imperceptible to the average listener - like switching between a great sound and uber hi-fi quality. I'm not sure I know what this oft quoted [i]headroom[/i] is but for me 18v offers a tad more width and sparkle. As a result I do all my home noodling and rehearsal room stuff at 9v to save battery life and to give myself a better chance of achieving that ultimate sound I play live with 18v. Who knows, someone out there might appreciate the difference.

[MB1]

[quote name='benwhiteuk' post='363982' date='Dec 26 2008, 11:40 PM']What are the advantages of using an 18V pre amp over a 9V…or wiring your pre amp for 18V instead of 9V?

I’ve got a pre amp for the Jazz bass that I’m building and it can be run at either 9V or 18V. I’m probably going to wire it as a 9V cos my experience of 18V pre amps tends to be that the output is so high that it saturates the input of my effects leading to a really sh*t digital distortion kind of sound on a lot of my pedals, but I’ll experiment with a 9V and 18V configuration before I decide what I’ll stick with.

Any suggestions or tips as to why 18V would be advantageous over 9V?

Ta very much [/quote]

MB1.
Take 2 9v pre amps into the shower?......not me!....
Sorry!...I'll get me coat!

[Rogerio Rosario]

.
My bass collection have 2 EMG , i use 9V ...tried with 18V , but did not liked de 18V because was more grainy and less Bass!


[url="http://www.MakeMusicNews.com"]www.MakeMusicNews.com[/url]

r

[umph]

more voltage = more gain on tap = the opamp amp can handle bigger swings in the voltage without distorting meaning a cleaner sound that goes higher and lower

[wesfinn]

i have an 18v emg running my fretless zoot funkmeister and i can get such a great range of tones with that and the aero pickups. in my zoot groovemeister P bass i have an obp 3 aguilar with emgs but this is only 9v, this bass is RIDICULOUSLY high output and i cant really have the volume past a quarter on the bass unless i want more cabs to go to the hospital! awesome range of tones though! shame the aguilar doesnt have a trim pot for the gain!

if you want more head room 18v is great but isn't nessesary of you want a big sound. just get an aguilar pre amp!

[bassanton]

Read somewhere that 18v circuits are more silent than 9v circuits (if this is the only variable). Can anyone confirm this?

[Mikey R]

[quote name='Crazykiwi' post='364171' date='Dec 27 2008, 03:08 PM']18v allows more headroom but this probably needs a bit of explanation. It's a bit like the difference in bandwidth between a 1mb connection and an 8mb connection and the difference all depends on what you want to do.[/quote]

[quote name='umph' post='453504' date='Apr 3 2009, 04:48 PM']more voltage = more gain on tap = the opamp amp can handle bigger swings in the voltage without distorting meaning a cleaner sound that goes higher and lower[/quote]

Hi gents, do you know what the maximum peak to peak voltage of a passive pickup normally is? I thought it was in the range of tens of millivolts but Im guessing this is wrong.

Just having a quick think about this, it may be that the op amps have a higher gain bandwidth product when driven by a higher voltage, so this would mean better high frequency response?

EDIT: A quick google shows the active EMG pickups put out around 0.7v to 1.4v RMS, so that would be 1v to 2v peak, if we were talking about steady sine waves. Which we're not. Hmm, not getting any closer to finding this out.

Edited April 11, 2010 by Mikey R

[Lfalex v1.1]

[quote name='Mikey R' post='802815' date='Apr 11 2010, 05:51 PM']Hi gents, do you know what the maximum peak to peak voltage of a passive pickup normally is? I thought it was in the range of tens of millivolts but Im guessing this is wrong.

Just having a quick think about this, it may be that the op amps have a higher gain bandwidth product when driven by a higher voltage, so this would mean better high frequency response?

EDIT: A quick google shows the active EMG pickups put out around 0.7v to 1.4v RMS, so that would be 1v to 2v peak, if we were talking about steady sine waves. Which we're not. Hmm, not getting any closer to finding this out.[/quote]

I tried plugging a bass into the "line level" input on a regular stereo hifi amp once.
Nothing of any great volume came out.
In desparation, I plugged it into a Moving Magnet phono stage..
With the exception of excess equalization from the RIAA curve applied to the signal, it worked fine. This was using a Passive 80's Westone with "P" pick-ups. IIRC, MM phono cartridges make around 30mV peak to peak, so I'd guess it'd be in that region (millivolts, as you suggested) assuming that there's no active jiggery-pokery going on!
It's difficult to isolate whether or not 18v(+) pre-amps are better, as they frequently surface on superb basses, so of course they sound good.
Only the switching of 2 9v batteries (as suggested in an earlier post (nice idea, BTW)) from series to parallel into a pre-amp designed to take either will yield a definitive answer, and even that assumes optimum operation on both types of power source.
It's not all about absolute output level either. I have actives with 18v power which are not as hot as my Yamaha Attitude (passive, and evilly hot). It is all about transient headroom without clipping the wave form. The overall output is just as dependent on the pick-ups in use.
That said, My Zoot has a single SD MM-style Humbucker with an East E-Pro @ 18v. Switch it (the pick-up) into Series, and see your amp's input stage [i]melt[/i]
Perhaps that's why it's buffered (etc) on the Sterling and 'Ray 5 switcing!!