Takamine Palathetic pickups as passive?

[jparis51]

Has anyone ever tried disconnecting a Tak Palathetic Pickup from it's onboard preamp and wiring it directly to the endpin jack in order to run it as a passive UST into a good outboard preamp? I'd love to hear about your experience.

I have a couple of rare Takamine J-15E archtops, designed in 1981 as a heavily-advertised prototype for Ry Cooder. Less than 200 were brought into the US and production ceased in 1983.

My understanding is the Palathetic pickup itself has changed little since it was introduced in the 70s, but the "Old Brown" and TK-3 preamps in these guitars are surely outdated. Since these are the best playing acoustics I've ever owned I'm thinking about this as a way to breathe new life into them.

[Petty1818]

Originally Posted by jparis51

Has anyone ever tried disconnecting a Tak Palathetic Pickup from it's onboard preamp and wiring it directly to the endpin jack in order to run it as a passive UST into a good outboard preamp? I'd love to hear about your experience.

I have a couple of rare Takamine J-15E archtops, designed in 1981 as a heavily-advertised prototype for Ry Cooder. Less than 200 were brought into the US and production ceased in 1983.

My understanding is the Palathetic pickup itself has changed little since it was introduced in the 70s, but the "Old Brown" and TK-3 preamps in these guitars are surely outdated. Since these are the best playing acoustics I've ever owned I'm thinking about this as a way to breathe new life into them.

A couple of things. First, just to clarify, it’s not a UST pickup. It’s actually six individual transducers that are basically built into the bridge. That’s why Takamine guitars are heavily built and often sound a bit muffled unplugged. Second, I can’t remember where I read this but apparently the older preamps are considered to be better. I remember one band in particular that swore by the late 80s/Early 90s Takamine, built in preamps. You might not need to go passive at all. Still, you could just leave it as is and get an outboard pedal like the session di to sweeten the tone.

[guitaniac]

Some of the Tak preamps are interchangeable, with the pickup being plugged into them via a mini-plug. Some of the Tak preamps also have a second input to blend in a second source which you might want to add. Here's an info page on the preamps.

https://www.takamine.com/pre-amps

If your system also connects with a plug, it would be easy enough to get a mini-jack and wire it to a passive strap-jack, if that's what you really want to do. It might be better to leave the active onboard system as is and try to enhance your sound with a ToneDexter or some other piece of outboard gear. I recall that at one time John Jorgenson used his signature Takamine to demo modeling with the DTAR Mama Bear. It worked decently well for him.

Here's a vid which was copied off the the old DTAR website:

https://www.youtube.com/watch?v=furlMtpxZNo


I have a friend who replaced his old Tak with a Fishman Matrix Infinity-equipped Martin dread last year. He was surprised to discover that the new rig is more feedback prone. That palathetic pickup system still has some competitive qualities. It has good feedback resistance and good string balance unless one of the crystals goes bad or becomes disconnected somehow. (Another friend with a Tak had to get his pickup system fixed last year. Two of the crystals had gone dead.)

[guitaniac]

Originally Posted by Petty1818

A couple of things. First, just to clarify, it’s not a UST pickup. It’s actually six individual transducers that are basically built into the bridge. That’s why Takamine guitars are heavily built and often sound a bit muffled unplugged. Second, I can’t remember where I read this but apparently the older preamps are considered to be better. I remember one band in particular that swore by the late 80s/Early 90s Takamine, built in preamps. You might not need to go passive at all. Still, you could just leave it as is and get an outboard pedal like the session di to sweeten the tone.

I wonder how the Session DI compares with Takamine's Cool Tube preamp. That would be an interesting comparison.

[jparis51]

Thanks for the replies folks. I'm familiar with the design of the Palathetic Pickup, and with the newer Tak preamps that are interchangeable. Mine is not, and the pickup is hard wired to it.

I'm afraid I'm pretty set in not wanting to use the onboard preamp, as I've become convinced much of the dreaded piezo quack we all combat is actually from a typical 9-volt preamp's lack of headroom. Besides, I hate batteries!

I've got a guitar with a Fishman AG-Series passive undersaddle pickup that gives me very little quack going into a Grace Felix pre. Since the Tak Palathetic is a more serious design with its individual crystals, I'm thinking it should sound even better.

I just want to know if anyone's tried this. I can't see why it shouldn't work well, unless the output is different somehow from a passive Fishman or, for example, a K&K. Can't see why that should be.

And I know I will probably be devaluing the guitar, but hey it's my guitar!

[jonfields45]

Originally Posted by jparis51

I've become convinced much of the dreaded piezo quack we all combat is actually from a typical 9-volt preamp's lack of headroom.

You are another casualty of good marketing. Doubling the power supply or using a 50% resistive divider on input of the preamp both give you 6 dB more headroom (the second example would take that out of the total SNR). Since modern electronics has SNR to burn, if headroom was the source of a pickup's problem, a designer would simply pad the input.

I am no fan of batteries or complex electronics in my guitars too.

[guitaniac]

Originally Posted by jparis51

Thanks for the replies folks. I'm familiar with the design of the Palathetic Pickup, and with the newer Tak preamps that are interchangeable. Mine is not, and the pickup is hard wired to it.

I'm afraid I'm pretty set in not wanting to use the onboard preamp, as I've become convinced much of the dreaded piezo quack we all combat is actually from a typical 9-volt preamp's lack of headroom. Besides, I hate batteries!

I've got a guitar with a Fishman AG-Series passive undersaddle pickup that gives me very little quack going into a Grace Felix pre. Since the Tak Palathetic is a more serious design with its individual crystals, I'm thinking it should sound even better.

I just want to know if anyone's tried this. I can't see why it shouldn't work well, unless the output is different somehow from a passive Fishman or, for example, a K&K. Can't see why that should be.

And I know I will probably be devaluing the guitar, but hey it's my guitar!

Now THAT is interesting news. All we need for a nearly quack-free UST experience is a Fishman AG series UST and a Grace Design Felix (or Alix or Bix, I presume).


Taking a pickup system apart and using the passive transducer with an outboard preamp doesn't always work well. I had a spectacular failure with trying to use a DTAR Wavelength transducer with outboard preamps. In the case of the piezo crystal palathetic system, I suspect it will work, but can't say for sure. If you decide to go ahead and try this experiment, please let us know how it goes.

[SpruceTop]

A thing about the Takamine Palathetic pickup is that the guitar strings don't directly contact the guitar's bridge but sit on top of the palathetic crystals which are suspended in a housing that bolts to the bridgeplate. There is actually a slot cut right through the bridge and top where the bridgesaddle and palathetic crystals are located in the housing assembly. This pickup assembly does pick up both string and top vibration but I've always heard a bit of a loss of direct acoustic attack in these guitars.

[James May]

I've tried a number of modern Taks with Palathetic pickups. They work great with ToneDexter of course, but more to the point of this thread the question is how will they sound without the onboard preamp? Since they are piezo crystals, mounted somewhat away from direct string contact and picking up more sound board than typical USTs, they would be expected to sound not as quacky as USTs, with or without a preamp, onboard or outboard. But still fairly unnatural. My listening tests confirm that.

The quack exhibited by most USTs is result of direct (or nearly direct) contact with the strings. That's how strings sound. It's not lack of headroom, it's not nonlinear behavior of the crystals. Those are urban legends. I have heard of some onboard preamps that have limited headroom, but that's another problem altogether.

I've not measured one, so I don't know the capacitance (and resultant impedance profile) of the Palathetic, but I would certainly expect it to work well into 5Mohms or more, and perhaps even into 1Mohm. If it was me, I would not hesitate for one moment to try it directly wired to the jack, without the internal preamp. If you don't want to use a ToneDexter, there are plenty of high quality preamps you could use to get a decent amplified signal (though not of Dexter quality). It all depends on what sound you want of course.

I hope this helps.

[guitaniac]

Originally Posted by James May

I've not measured one, so I don't know the capacitance (and resultant impedance profile) of the Palathetic, but I would certainly expect it to work well into 5Mohms or more, and perhaps even into 1Mohm. If it was me, I would not hesitate for one moment to try it directly wired to the jack, without the internal preamp. If you don't want to use a ToneDexter, there are plenty of high quality preamps you could use to get a decent amplified signal (though not of Dexter quality). It all depends on what sound you want of course.

I hope this helps.

The OP is using a Grace Design Felix to preamp his passive pickups, so he's definitely got the "quality preamp" thing covered.

The possibility of running passively to a ToneDexter does bring up a small possible issue, however. If the user happens to prefer a Dexterized signal/dry signal blend, as some of us prefer, TD's 1 Mohm input impedance might not be enough to get a fully balanced dry signal with some of the passive piezo pickups out there. I had a bit of this problem (dry signal lacking a full bass end) with one of my passive pickups before converting it to an active system. (Now I have the opposite problem, LOL. The onboard preamp which I salvaged from a Matrix Infinity system yields a very excessively bassy signal. Thank goodness TD can compensate for it with the Dexterized signal, and thank goodness I only prefer about 20% dry signal in the blend. TD's tone controls can compensate pretty well for the excessive bass in the dry signal.)

[guitaniac]

Originally Posted by jonfields45

You are another casualty of good marketing. Doubling the power supply or using a 50% resistive divider on input of the preamp both give you 6 dB more headroom (the second example would take that out of the total SNR). Since modern electronics has SNR to burn, if headroom was the source of a pickup's problem, a designer would simply pad the input.

I am no fan of batteries or complex electronics in my guitars too.

I have to admit to being impressed that all the Grace Design preamps have "A better than 30VDC internal operating voltage (which) provides for incredible headroom. Are you saying this is all to maintain a high SNR and/or to help market the product?

[jonfields45]

Originally Posted by guitaniac

I have to admit to being impressed that all the Grace Design preamps have "A better than 30VDC internal operating voltage (which) provides for incredible headroom. Are you saying this is all to maintain a high SNR and/or to help market the product?

It is probably because the circuit topology they chose to use needs the higher voltage to bias all the active devices centered into the appropriate "on" state. It can also be about improving SNR. But it is only about avoiding harmonic distortion (lack of headroom) if you run the primary input too hot.

Baggs has a product called Session that intentionally limits the headroom to achieve harmonic distortion (they market it as saturation). A higher power supply voltage can be used to achieve higher total SNR, but if lack of "headroom" (too much harmonic distortion) is your issue, it is only one of the alternatives to fix that problem.

As James states above, a lot of what we think to be true are Urban Myths whose roots were in some company's advertising campaign.

[James May]

Originally Posted by guitaniac

...
The possibility of running passively to a ToneDexter does bring up a small possible issue, however. If the user happens to prefer a Dexterized signal/dry signal blend, as some of us prefer, TD's 1 Mohm input impedance might not be enough to get a fully balanced dry signal with some of the passive piezo pickups out there. I had a bit of this problem (dry signal lacking a full bass end) with one of my passive pickups before converting it to an active system. (Now I have the opposite problem, LOL. The onboard preamp which I salvaged from a Matrix Infinity system yields a very excessively bassy signal. Thank goodness TD can compensate for it with the Dexterized signal, and thank goodness I only prefer about 20% dry signal in the blend. TD's tone controls can compensate pretty well for the excessive bass in the dry signal.)

This is a valid point, but only for those that like to blend some passive UST with the WaveMap. Modern ToneDexters (starting with serial number 1000) have the ability to present either a 1Mohm input OR a 10Mohm input impedance. It's a little trick I thought of to help out with just this situation. If you want the normal 1Mohm or don't care, then use a standard mono phone plug. Most folks will just do that and be happy!

But, if you want 10Mohm, use a TRS plug with RING disconnected and voila, the input impedance is 10Mohm! You could also use a standard TRS cable with TRS (stereo) plugs on both ends. If you do it that way, make sure the RING connection is not connected at the source end.

[James May]

Originally Posted by guitaniac

I have to admit to being impressed that all the Grace Design preamps have "A better than 30VDC internal operating voltage (which) provides for incredible headroom. Are you saying this is all to maintain a high SNR and/or to help market the product?

As Jon Fields said, a high supply rail will allow high signal-to-noise ratio (SNR) and that can translate to, with careful design, very low noise floor and low hiss.

ToneDexter uses a 30V supply rail, and I took a lot of care with extra steps and circuitry to minimize the noise floor even further. It's a pro box, used by some of the most demanding musicians, and we didn't want to have to make any excuses.

[guitaniac]

Originally Posted by James May

This is a valid point, but only for those that like to blend some passive UST with the WaveMap. Modern ToneDexters (starting with serial number 1000) have the ability to present either a 1Mohm input OR a 10Mohm input impedance. It's a little trick I thought of to help out with just this situation. If you want the normal 1Mohm or don't care, then use a standard mono phone plug. Most folks will just do that and be happy!

But, if you want 10Mohm, use a TRS plug with RING disconnected and voila, the input impedance is 10Mohm! You could also use a standard TRS cable with TRS (stereo) plugs on both ends. If you do it that way, make sure the RING connection is not connected at the source end.

What a clever way to make a higher input impedance available. Very admirable. Thanks for the info on that and the info on TD's noise minimizing circuitry. I've had zero complaints about noisiness since reading your advice (which is also on the Audio Sprockets website) on how to avoid picking up a ground hum.