The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Archtops

Reply
 
Thread Tools
  #1  
Old 09-22-2020, 07:18 PM
mikehartigan mikehartigan is offline
Registered User
 
Join Date: Nov 2018
Posts: 36
Default Pickup recommendation for Archtop Acoustic with floating bridge

I originally asked this in the Acoustic Amplification forum:
https://www.acousticguitarforum.com/...d.php?t=592839
@ljguitar suggested this might be a better place for it, so here it is.

I'm looking to replace the Shadow NanoFlex HD under saddle pickup in my Epi Century Zenith. I'm looking for something that will best capture a true acoustic sound through a PA system with minimal signal processing, though I'm not averse to adding something like a Para Acoustic DI box, if necessary. FWIW, my budget is not unlimited, but neither is it anemic.

I'm thinking maybe an undersaddle pickup combined with a microphone along the lines of an LR Baggs Anthem. The problem with the Anthem, if it is, indeed, a problem, is that my Zenith is an archtop with a floating bridge. Thus, no bridge plate to mount the mic component. Also, the F-holes may pose a challenge for installation, not to mention that the preamp and controls are designed to mount inside a round sound hole.

@James May has me salivating over a project that is about to bear fruit involving an Archtop, Ultra Tonic pickup, and a blend pot scheme, so I'm looking forward to more detail on that.

Recommendations? Suggestions?
__________________
I own 6 guitars and a banjo, I drive a Hummer, and I brew my own beer. Staying cool is not something I have to work at.
Reply With Quote
  #2  
Old 09-22-2020, 07:31 PM
Mandobart Mandobart is offline
Registered User
 
Join Date: Aug 2015
Location: Washington State
Posts: 2,104
Default

I put this Kent Armstrong on my Eastman. I have a JJB twin head under the soundboard. I don't like the idea of an undersaddle pu on an archtop as the strings to saddle to base to soundboard physical contact is even more important on an archtop than on a pin bridge.

And as we all know, a decent mic better captures the real acoustic sound than the best pickup.
Reply With Quote
  #3  
Old 09-23-2020, 05:10 AM
Howard Emerson Howard Emerson is offline
AGF Sponsor
 
Join Date: Dec 2003
Location: Huntington Station, New York
Posts: 6,647
Default

Quote:
Originally Posted by mikehartigan View Post
I originally asked this in the Acoustic Amplification forum:
https://www.acousticguitarforum.com/...d.php?t=592839
@ljguitar suggested this might be a better place for it, so here it is.

I'm looking to replace the Shadow NanoFlex HD under saddle pickup in my Epi Century Zenith. I'm looking for something that will best capture a true acoustic sound through a PA system with minimal signal processing, though I'm not averse to adding something like a Para Acoustic DI box, if necessary. FWIW, my budget is not unlimited, but neither is it anemic.

I'm thinking maybe an undersaddle pickup combined with a microphone along the lines of an LR Baggs Anthem. The problem with the Anthem, if it is, indeed, a problem, is that my Zenith is an archtop with a floating bridge. Thus, no bridge plate to mount the mic component. Also, the F-holes may pose a challenge for installation, not to mention that the preamp and controls are designed to mount inside a round sound hole.

@James May has me salivating over a project that is about to bear fruit involving an Archtop, Ultra Tonic pickup, and a blend pot scheme, so I'm looking forward to more detail on that.

Recommendations? Suggestions?
Mike,
For many years I amplified my 1930 Gibson L-5 with a Fishman SBT-E soundboard pickup and a Crown GLM-200 mini condenser mic.

The mic was suspended under the pickguard, hanging in front of the lower F hole. The SBT-E was mounted on the face of the guitar near the treble end of the bridge.

They were both wired to a 1/4" stereo TRS jack. I ran it through a Rane AP-13 at first, and then through a Fishman Pocket Blender.

It was the best of both worlds in terms of higher volume acoustic archtop sound.

There were no controls mounted on the instrument. Everything was outboard, plugged into whatever PA system was available.

Regards,
Howard Emerson
__________________
My New Website!
Reply With Quote
  #4  
Old 09-29-2020, 07:59 PM
nkatsonis nkatsonis is online now
Registered User
 
Join Date: Sep 2010
Location: Reston, VA
Posts: 675
Default

Jason Krivo makes an excellent humbucker that can simply be attached to the guitar with (supplied) blue tack. I replaced a handmade Kent Armstrong with a Krivo and am very satisfied. It's quiet, feedback resistant, and, in my opinion, sounds great.
Reply With Quote
  #5  
Old 09-30-2020, 04:12 AM
Howard Emerson Howard Emerson is offline
AGF Sponsor
 
Join Date: Dec 2003
Location: Huntington Station, New York
Posts: 6,647
Default

Quote:
Originally Posted by nkatsonis View Post
Jason Krivo makes an excellent humbucker that can simply be attached to the guitar with (supplied) blue tack. I replaced a handmade Kent Armstrong with a Krivo and am very satisfied. It's quiet, feedback resistant, and, in my opinion, sounds great.
The OP's quest is for a more acoustic sounding option, therefore a magnetic humbucker isn't an option, regardless of how pleasing the resulting tone would be.

Regards,
Howard Emerson
__________________
My New Website!
Reply With Quote
  #6  
Old 09-30-2020, 12:40 PM
nkatsonis nkatsonis is online now
Registered User
 
Join Date: Sep 2010
Location: Reston, VA
Posts: 675
Default

Quote:
Originally Posted by Howard Emerson View Post
The OP's quest is for a more acoustic sounding option, therefore a magnetic humbucker isn't an option, regardless of how pleasing the resulting tone would be.

Regards,
Howard Emerson
Understood, Howard. I don't pretend to be the player that you are, but I am curious if you have heard one of Jason's pickups. To my ears, they capture the acoustic tone of the guitar far better than any other magnetic pickup. But, yes, they are still not the equivalent of a microphone. Frankly, though, if my goal is to obtain the best acoustic sound, assuming that both the guitar and the venue suited, I'd personally rather just set up a mic. But I suppose that is not a response to the OP's request.
Reply With Quote
  #7  
Old 09-30-2020, 05:47 PM
James May's Avatar
James May James May is offline
AGF Sponsor
 
Join Date: Dec 2015
Location: Nevada City, CA
Posts: 531
Default

As promised, a description of my first experience with installing my Ultra Tonic pickup in a high quality, carved archtop. In this case, I bought an Eastman AR610. Itís 17Ē, spruce top with mahogany back and sides. This guitar is beautifully made and has a very rich, resonant sound. Like all archtops, it is more midrange focused than a flat top, but this one is quite well balanced and has a healthy amount of bass. It came with a Lollar floating humbucker with thumbwheel volume and tone controls under the pickguard.
AR610CE.jpg

Executive summary:
It was a success and Iím very pleased with the sounds available! Here is a very short audio clip with four segments: 100% Ultra Tonic, ~67/33 blend, ~33/67 blend, 100% humbucker, recorded direct into the sound card. Iím not much of a jazz player, but here are some Freddie Green chords to give you a sense.


For those not familiar with the Ultra Tonic, it has an integrated feedback cancellation sensor that clears up low end mud and at the same time increases feedback immunity by at least 10dB.

First things first: access and visibility
Having the right tools is critical. I searched around and luckily found the right bits to make this tool:
pickup placement tool.jpg

https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

https://www.amazon.com/Ullman-High-T...l%2C233&sr=1-3

Then I found this nifty inspection camera which allows stills or video to be captured on your smart phone. Fortunately, it just fit into the f-holes of the Eastman. The f-holes are the biggest Iíve seen, and Iím sure this camera wonít fit into most f-holes. Iím looking for a smaller alternative for the next install.
Ullman inspection mirror.jpg
https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

Installation

The installation was fairly easy with the above tools. I always use adhesive putty and neodymium magnets to both position and clamp the discs. You just hover until you find the strongest pull, then let it down and it does the clamping for you. Go do something else for 10 minutes while the gel superglue sets up.

The magnet that came with the flex arm was sufficiently strong to work as is. If it hadnít been, I would have simply positioned one of my 3/8Ē x 1Ē neodymium magnets in its place with another ball-end clamp.

I surrounded the bridge with artist tape, marked the locations of the posts (outer marks on the tape). I removed the strings and bridge. This guitar is X-braced. I determined how close the braces were to the post locations, which is the ideal place to put the two main sensor discs. Fortunately, sensor locations on a guitar like this (with no bridge plate underneath) are not super critical. Due to the locations of the braces, I decided to move the discs inward just a little so as to not have them right up against the braces. That would have worked, but would result in slightly less signal strength out of the Ultra Tonic.
treble disc top.jpg
inspection camera.jpg
camera view on phone.jpg
tool with disc.jpg
installing treble disc.jpg
interior disc 2 glued.jpg

After installing the two main sensors, I located the feedback cancellation sensor at a point further back. Its location is not critical at all. Typically, I put it on the bass side, but it doesnít have to be. Its role is to pick up the same resonances as the main sensors, but far less of the direct string vibrations. It has opposite polarity to the main sensors. When the right amount of it is mixed in with the main sensors, the good stuff remains and the bad stuff disappears. And yes, I have a patent on this seemingly simple idea.
installing feedback sensor.jpg
all 3 sensors inside.jpg

Setting the Ultra Tonic
The Ultra Tonic sensor assembly has a quick disconnect to the endpin jack with circuit board. This makes it easy get it in and out of the round or f-holes. I ran it out of the f-hole, plugged it into the endpin circuit, and plugged into a full range amp.
PCB-alone-midres.jpg

The 12 position switch functions as a stepped attenuator which determines how much of the feedback cancellation sensor is mixed into the main sensors. It is passive, and the mixing uses capacitor dividers since piezo sensors are in effect capacitors. There is no frequency dependence in the mixing circuit. The exact resonances that are dealt with are only dependent on the guitar.

Finding the right setting for the 12-position switch takes just 10 minutes if you know what to listen for. Alternately, I have an automated calibration system available which does this for you in a few seconds.

To wrap up the pickup installation, I drilled out the endpin hole to 15/32Ē with my StewMac reamer, and pulled it into place with this homemade jack puller made out of copper tubing. Itís stiff enough to hold its shape, but can be bent a little if necessary to get it up for access through an f-hole, as was necessary in this case.
jack puller.jpg

Before tightening the nut, I twisted the endpin jack to take up the internal cabling slack and keep it from touching the wood.
installed wiring.jpg

This StewMac tool was also very helpful for fishing wiring and the jack around. That hook on the end is sized to grab the endpin jack tightly enough to pull it, but will let go without too much force. Itís bendable and very handy.
stewmac tool.jpg

Passive Blending

The mag/piezo blending circuit required a good deal of design effort, as it is not trivial to successfully blend a passive magnetic pickup with a passive piezo-based transducer system. However, I am happy to report I was able to achieve the following design goals:
  • Uses the same mag volume and tone pots. I shielded them with copper tape, and scooted the tone control over to make room for the blend control.
  • An Ultra Tonic volume control was not necessary since the mag pickup is hotter. Therefore, I cannibalized the existing Ultra Tonic volume control and turned it into a blend control with a variable treble bleed circuit so as to not lose acoustic highs when blending with the mag. This very similar to the variable bleed circuit that my standard Ultra Tonic volume control uses.
  • Mag volume control has a new treble bleed circuit so that reduced mag gain does not destroy the characteristic frequency bump that mag pickups achieve working into typical cable capacitances.
  • Since the mag is hotter, it needs to be turned down some to put it on a par with the Ultra Tonic. Then, the blend functions very well with a smooth and usable transition from full mag to full Ultra Tonic.
shield on top.jpg
modified controls.jpg

Whatís next

I may decide to package the mag volume/ mag tone/ blend circuit as a single stick-on manufactured assembly, and make it available as a special Ultra Tonic Archtop model for those wishing to do what Iíve done here. The design work is done, and the installation method is worked out. Making a product out of it will depend on how much interest I get on this idea.
__________________
James May
Audio Sprockets
maker of ToneDexter
James May Engineering
maker of the Ultra Tonic Pickup
Reply With Quote
  #8  
Old 10-01-2020, 05:02 AM
Howard Emerson Howard Emerson is offline
AGF Sponsor
 
Join Date: Dec 2003
Location: Huntington Station, New York
Posts: 6,647
Default

James,
You have the patience of a saint!

That installation is beautifully executed, and well explained in pictures and text!

The sound sample really gives a clear idea of what one could expect with no room ambience: The cold hard truth!

Well done!

Howard Emerson
__________________
My New Website!
Reply With Quote
  #9  
Old 10-01-2020, 05:12 AM
Howard Emerson Howard Emerson is offline
AGF Sponsor
 
Join Date: Dec 2003
Location: Huntington Station, New York
Posts: 6,647
Default

Quote:
Originally Posted by nkatsonis View Post
Understood, Howard. I don't pretend to be the player that you are, but I am curious if you have heard one of Jason's pickups. To my ears, they capture the acoustic tone of the guitar far better than any other magnetic pickup. But, yes, they are still not the equivalent of a microphone. Frankly, though, if my goal is to obtain the best acoustic sound, assuming that both the guitar and the venue suited, I'd personally rather just set up a mic. But I suppose that is not a response to the OP's request.
I agree on just setting up a mic. Of course it's very dependent on having an audience that's willing and able.

After that it's cake.

As far as hearing a particular magnetic pickup goes: They're all based on a similar principle, and what happens when people 'listen' to them, is they're not just hearing the pickup, but the room in which the amplifier's speaker is greatly affected by the ambience.

Yes, there's no doubt that all magnetic pickups have a certain 'voice', but none of them reproduce air.

Are they pleasant sounding? Absolutely.......sometimes, but it's usually got little to do with the pickup, and almost all to do with the player behind the wheel, but I digress.......

Give a listen to James May's sound sample in his post here. The last section is 100% magnetic pickup, direct.

No ambience.

Listen with headphones if you have them.

Regards,
Howard Emerson
__________________
My New Website!
Reply With Quote
  #10  
Old 10-01-2020, 11:49 AM
shufflebeat shufflebeat is offline
Registered User
 
Join Date: May 2016
Posts: 542
Default

Quote:
Originally Posted by James May View Post
As promised, a description of my first experience with installing my Ultra Tonic pickup in a high quality, carved archtop.
Nice work.
__________________
Give a man a fishing rod... and he's got the makings of a rudimentary banjo.
Reply With Quote
  #11  
Old 10-09-2020, 01:55 PM
Backcountry Backcountry is offline
Registered User
 
Join Date: Jul 2016
Posts: 76
Default

I'd buy at least one of those...maybe two...
__________________
If the Dawn Patrol gotta tell ya twice, they're gonna do it with a shotgun,
I'm cashing in this ten-cent life for another one.
Reply With Quote
  #12  
Old 11-23-2020, 01:14 PM
James May's Avatar
James May James May is offline
AGF Sponsor
 
Join Date: Dec 2015
Location: Nevada City, CA
Posts: 531
Default

I have built some of the Mag/Ultra Tonic blender boards that I previously designed. Here are some pics showing details and final mounting on the Eastman.
PCB top.jpg
mounted bottom view.jpg
final mounted.jpg

It works great! I am now going to offer this as an 'archtop w/ mag pickup' option for the Ultra Tonic.
__________________
James May
Audio Sprockets
maker of ToneDexter
James May Engineering
maker of the Ultra Tonic Pickup
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Archtops

Thread Tools





All times are GMT -6. The time now is 05:39 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright ©2000 - 2020, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=