The Acoustic Guitar Forum  

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Amplification (Electrified!!!)

Reply
 
Thread Tools
  #1  
Old 06-27-2012, 03:30 AM
VKB VKB is offline
Registered User
 
Join Date: Jun 2012
Posts: 85
Default Phantom power

Anyone care to make sure I'm understanding the following correctly from the Godin FAQ? It says you have to be plugged in to a mixer using a mic cord, so assuming your amp even has an XLR connection, how do you know whether it produces phantom power (what do I look for on the spec sheets)? Then the mic cable will take me from that at the amp to the normal 1/4" connection to plug into the guitar?

What is Phantom Power and what does it do for my Multiac Duet?
Quote:
Pantom power is most commonly used to provide the current used in condenser microphones. The power typically comes from a phantom power capable mixer and arrives at the mic via one of the three pins - called XLR connectors -in a standard mic cable. The under-saddle transducer and the I-Beam transducer in the Multiac Duet require active electronics, which means that they require power to operate. This is true of most pickup-equipped acoustic guitars and the power typically comes from a 9volt battery. The Multiac Duets offer you the choice of powering the guitar via the standard 9volt battery along with a standard guitar cord and from there into the amp of your choice, or you can use a standard mic cord to plug the guitar directly into a mixer and draw power back into the guitar and bypass the need for a battery. The advantages of this approach are that the mic cable is shielded against outside interference - such as radio frequencies - and the XLR connection locks the cable in place avoiding any accidental disconnections. Note: Not all mixers produce phantom power check your mixer owner's manual if you are unsure about this.
Reply With Quote
  #2  
Old 06-27-2012, 04:13 AM
VKB VKB is offline
Registered User
 
Join Date: Jun 2012
Posts: 85
Default

According to the following alpha plus review, this is it except the 24v* doesn't sound right, since the Godin duet/ Yamaha silent guitar etc. Use a 9v battery. Problem?

Quote:
Originally Posted by Bob Thomas
If you’re using a microphone or a line output from an instrument preamp or effects unit (either balanced or unbalanced, on XLR or jack) you’ll use Input One. On this input alone, 24 Volts of phantom power for condenser microphones is permanently present on the XLR, so if you’ve got a unit that doesn’t like to see Volts sitting across its XLR balanced output (the TC Electronic G-Natural springs to mind) then don’t plug it in here. On the other hand, if, like me, you either regularly use condenser microphones or you’ve got an XLR-terminated, cable-mounted preamp that needs phantom power to operate, you’ll be very happy indeed.
The review mentioned output two replacing a 9v battery specifically, but this doesn't sound right either (and some kind of modification is obviously required):
Quote:
Input Two is a high-impedance, unbalanced input with a stereo jack, best suited to pickups or line sources. The sole reason for the stereo jack is that there is an option (which requires an engineer) to add a +15V DC feed at the ring contact, giving you a source of power for any suitable electronics that are onboard your instruments. It’s worth noting that this supply isn’t the same as you’d commonly find powering the microphone in pickup/microphone combinations, it is simply here to give you an alternative power supply to the ubiquitous 9V battery, and you’d need to have your onboard electronics rewired slightly to take advantage of it.

*and according to AER's spec page, that should probably be 48v anyway.

Last edited by VKB; 06-27-2012 at 06:20 AM.
Reply With Quote
  #3  
Old 06-28-2012, 03:02 PM
guitaniac guitaniac is offline
Registered User
 
Join Date: Jan 2004
Posts: 4,113
Default

Hi VKB,

Its been many years since I've owned a Godin Duet model, but I checked the Godin FAQ sheet and apparently the Duet model has an XLR input (mic cable input) as well as a 1/4" input. If the PA mixer has phantom power, you can power the guitar (no onboard battery needed) with a mic cable running from the mixer (with phantom power turned on) to the guitar's XLR input.

Some guitar amps have phantom power on the mic input, but that's usually intended for folks who want to run a condenser vocal mic thru the amp. You'll need two mic inputs with phanton power to run both a vocal mic and your Duet model Godin battery free. That'll probably narrow down your amp choices quite a bit (if you happen to be set on running everything thru an amp, rather than a PA system). I can tell you that the Fishman Solo Amp has two phantom powered mic inputs, so that's one possibility.

I hope that helps explain things. Running thru a phantom powered mic cable (as opposed to a mono guitar cable) can also be quieter in some situations, so saving on batteries is only one of the advantages.

Gary
Reply With Quote
  #4  
Old 06-29-2012, 08:34 AM
VKB VKB is offline
Registered User
 
Join Date: Jun 2012
Posts: 85
Default

Hi, thank you so much for the info & fishman solo (performance?) recommendation. That thing looks awesome, and with consensus 5 star reviews.

Unfortunately Godin has since informed me that their FAQ is actually wrong & needs to be updated- that their concert duets no longer run on phantom power. Yamaha also told me their sln130nw doesn't either, but this guy really didn't seem certain, & all their previous silent guitars did have that capability, so I'll be pursuing that further.

In the meantime, do you know if those mic outputs with 48v phantom power designed for condenser mics, those won't work for a guitar that takes a 9v battery anyway, right? I have to find an amp with a 9v phantom power output, or does it matter?

Thanks again.
Reply With Quote
  #5  
Old 06-29-2012, 09:55 AM
guitaniac guitaniac is offline
Registered User
 
Join Date: Jan 2004
Posts: 4,113
Default

The Line6 Variax 300 Classical was a guitar which was phantom powered by a power module. You could use an onboard battery with it, but battery life was very poor.

Line6 doesn't make this guitar model any more, but there may be a few used ones around. Be sure the power module comes with it.

Another (pretty expensive) option is to put passive LR Baggs Hex pickups (six individual mini-saddles with a passive pickup in each one), or passive RMC Hex pickups, in the guitar and use an outboard preamp with it. I have the passive Baggs Hex system in my thin-bodied classical. It works very well with my Fishman Platinum Pro EQ outboard preamp.

A much cheaper battery-free solution would be to put a Mi-Si Acoustic Trio pickup system in the guitar. This is an undersaddle pickup system which uses a super capacitor to power the system. You plug the charger in for one minute and you're good for several hours of playing time (up to eight hours, they say). I had the Mi-Si Acoustic Trio in one of my guitars for awhile and it did indeed work as claimed.

I hope that gives you some useful ideas.
Gary
Reply With Quote
  #6  
Old 06-29-2012, 10:06 AM
guitaniac guitaniac is offline
Registered User
 
Join Date: Jan 2004
Posts: 4,113
Default

With respect to using 48v phantom power to power an onboard pickup system, that would only work if the pickup system is designed for that (as the Godin Duet models apparently were at one time). You'd either need an XLR plug or TRS (tip-ring-sleeve) 1/4" stereo plug to deliver the phantom power. The pickup system would need to be set up to utilize that power.
Reply With Quote
  #7  
Old 06-29-2012, 10:23 AM
guitaniac guitaniac is offline
Registered User
 
Join Date: Jan 2004
Posts: 4,113
Default

Here's an aftermarket pickup system which is designed to operate on phantom power if desired.
http://www.schattendesign.com/artist_preamp.htm

Notice that you need a special cable, CAB-1, to use 48v phantom power off a mic output. That cable has an XLR connector on one end and a TRS 1/4" plug on the other end.

They also have an 18v outboard power module (takes two 9v batteries) available if you want to power it with that way.

Gary
Reply With Quote
  #8  
Old 06-29-2012, 05:33 PM
jimbriz jimbriz is offline
Registered User
 
Join Date: Dec 2009
Posts: 105
Default

My fishman Artist supplies 24 volt phantom power but it seems like everything requires 48 volts. So what is thier reasoning.
__________________
Taylor 315 CE
Taylor 324e
Tacoma JM9-K&K
Reply With Quote
  #9  
Old 06-29-2012, 07:34 PM
sdelsolray sdelsolray is offline
Charter Member
 
Join Date: May 2004
Location: Portland, OR
Posts: 4,157
Default

Quote:
Originally Posted by jimbriz View Post
My fishman Artist supplies 24 volt phantom power but it seems like everything requires 48 volts. So what is thier reasoning.
The official industry accepted balanced phantom standard, adopted in 1973 as IEC 268-15/DIN 45596, has changed over the years. Basically it allows a range of voltage between 9v and 52v at a current up to 10 milliwatts. Some microphones actually require a full 48v, but there are not that many that have this requirement. Many, work between 9v and 52v with only a few milliamps current.

More recently, 12v and 24v balanced phantom powers have been proposed as additional standards, but I'm not sure if they have ever been entirely adopted by the industry.
Reply With Quote
  #10  
Old 06-30-2012, 04:04 AM
pieterh pieterh is offline
Registered User
 
Join Date: Oct 2010
Location: Near Stockholm, Sweden
Posts: 1,535
Default

As the previous poster stated, phantom power is usually expressed as 48v whereas in practice the unit using the power takes what it needs. The offered power will be regulated to match the need.

What's more, don't confuse the battery rating with the Multiac's phantom power rating - there will be some sort of regulator or transformer internally to ensure that the right current goes to the electronics. Some DI boxes (eg BSS) can be powered from both 9v batteries and "48v" phantom power.
__________________
Mine: Taylor 414CE 2005/ES3; Guild D35 NT 1976/K&K Pure Mini; Fender MIM Classic 60s Tele 2008; Fender US Standard Strat 1992; G&L ASAT classic hollowbody 2005; Ibanez Musician fretless, 1980s; Landola classical 70s; Radial Tonebone Pz-Pre; Seymour Duncan Tube 84-40; Neumann KMS104

Ex-pat Brit in Sweden
Reply With Quote
  #11  
Old 06-30-2012, 12:09 PM
VKB VKB is offline
Registered User
 
Join Date: Jun 2012
Posts: 85
Default

Great, thanks all. I understand now. I thought I was at a dead end here, but looks like there are lots of options.


Quote:
Originally Posted by guitaniac View Post
The Line6 Variax 300 Classical was a guitar which was phantom powered by a power module. You could use an onboard battery with it, but battery life was very poor.

Line6 doesn't make this guitar model any more, but there may be a few used ones around. Be sure the power module comes with it.

Another (pretty expensive) option is to put passive LR Baggs Hex pickups (six individual mini-saddles with a passive pickup in each one), or passive RMC Hex pickups, in the guitar and use an outboard preamp with it. I have the passive Baggs Hex system in my thin-bodied classical. It works very well with my Fishman Platinum Pro EQ outboard preamp.

A much cheaper battery-free solution would be to put a Mi-Si Acoustic Trio pickup system in the guitar. This is an undersaddle pickup system which uses a super capacitor to power the system. You plug the charger in for one minute and you're good for several hours of playing time (up to eight hours, they say). I had the Mi-Si Acoustic Trio in one of my guitars for awhile and it did indeed work as claimed.

I hope that gives you some useful ideas.
Gary
Wow thanks so much for all the suggestsions & information. Seems like the best idea is the afrtermarket pickups. But some battery setups don't bother me as much, the TH90 for instance I understand takes AA's instead of 9v's. Wish more did. I just hate the idea of alkalines in my guitar. Rechargeable misi is interesting! Thanks again Gary, I really appreciate your time.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Amplification (Electrified!!!)

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Loading

All times are GMT -6. The time now is 02:53 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright ©2000 - 2014, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=