piezo quack

[Michael Martin]

In another thread, Terry Allen Hall mentioned "piezo quack":

 

"Are you strumming/picking too hard, thus overdriving the top and P/U and getting the dreaded 'piezo quack'?"

 

Got me thinking. I just heard a recording of me performing at open mike. It was kind of disappointing--my guitar sounded trebly and thin, but the vocals were OK. I also heard other performers on the same recording, same night, same sound system (everything through the house PA), and their guitars sounded better.

 

But I play different--I strum pretty hard, with a rather flexy pick--and that ain't gonna change. Never heard of "overdriving the top" but that could be it. At open mike I play a Tak EF350SMCSB (piezo pickup), and I set its EQ toward the bassy end, so that's not it. Should I get a soundhole pickup? If so, single coil or humbucker? Any good stuff out there that might work for this problem?

[Cripes]

I have no definitive answer for you but I do have one observation. I have one that is removable. It is about the size of the average person's thumb and is affixed to the guitar with a silly-putty stuff. It has a 1/8th inch jack and I plug it straight into my amp, or whatever. It never quacks. Not even a chirp. I think it has to do with the putty acting like a damper between the element and soundboard. Great thing about it is you can choose your guitar's sweet spot, which is different on each guitar, but usually near the sound hole. You can choose between bright or warm sounds just by moving it around. Made by Shadow.

[guitarist21]

That's a really cool idea for a pickup, Cripes. Where could I check one out, if possible? Do you think they have them at GC?

 

Ellen

[babablowfish]

Consider a K&K Pure Western mini. This consists of 3 separate transducers that sit under the bridge plate instead of under the saddle. You get very good tone but because the entire top of the guitar has now been turned into a mic of sorts, you can get feedback problems. In any case, thee will be no "quack." I am happy with how it worked out in my Parkwood and plan to buy another to put into my Yamaha FG-340.

[Cripes]

 

Originally posted by guitarist21 That's a really cool idea for a pickup, Cripes. Where could I check one out, if possible? Do you think they have them at GC? Ellen

 

 

Ellen - I bought that thing from Roselle Music on Lake Street (RT 20) just east of Bloomingdale Road in 1974. It has been bullet-proof so I never had to know if the company still has the product. I do believe the company is still around and I think they make high end stuff now. They're out of Germany.

[guitarist21]

 

Originally posted by Cripes Ellen - I bought that thing from Roselle Music on Lake Street (RT 20) just east of Bloomingdale Road in 1974.

 

 

I've heard of that place, but I thought it was in St Charles, kinda off of North Avenue (RT 64)?

[daklander]

 

Originally posted by guitarist21 That's a really cool idea for a pickup, Cripes. Where could I check one out, if possible? Do you think they have them at GC? Ellen

 

 

Dean Markley makes one that is similar and sounds decent.

[daklander]

MM, sounds more like an output problem. Are you running direct? If so, that could be the problem. Try a DI box/pre-amp into the pa before changing out the pickup unless the pickup sounds like crap anyway.

[Michael Martin]

 

Originally posted by daklander MM, sounds more like an output problem. Are you running direct? If so, that could be the problem. Try a DI box/pre-amp into the pa before changing out the pickup unless the pickup sounds like crap anyway.

 

Well, here's the weird thing. One of the songs I did that was recorded is fingerstyle, and the guitar sounds fine on that one. Good bass, mids...nice tone. But when I strum hard, much of the low end drops out, leaving a thin, watered-down effect.

 

There is a pre-amp or DI box in the bistro's PA system, so it's not direct. I think. I assume this would have to be because several players there don't use active pickups like my Tak has.

[Cripes]

 

Originally posted by guitarist21 I've heard of that place, but I thought it was in St Charles, kinda off of North Avenue (RT 64)?

 

 

Could be. The last time I visited that area I checked them out and they were in the process of closing down to re-locate to a smaller store. Lyle, the owner, was there and said after 50 years in the biz he was tired and leaving the store in the hands of a manager. He was still teaching violin but, now in his 80's, he was winding down. At one time he carried a full line of all the high end manufacturer's guitars. I bought my D-35 from him in '74 after deciding long and hard to take it over the Gibson H-Bird. My brother bought the same guitar, same day and a year later bought his Guild F-412 from him. His store was like a Mom/Pop GC. I think he mentioned concentrating on music lessons and keeping just enough product to keep his students equipped at this point.

[sdelsolray]

 

Originally posted by Michael Martin Well, here's the weird thing. One of the songs I did that was recorded is fingerstyle, and the guitar sounds fine on that one. Good bass, mids...nice tone. But when I strum hard, much of the low end drops out, leaving a thin, watered-down effect. There is a pre-amp or DI box in the bistro's PA system, so it's not direct. I think. I assume this would have to be because several players there don't use active pickups like my Tak has.

 

 

Piezo-based pickups generate different voltage (and impedance) levels depnding, for example, on how much they are stimulated. Strumming very hard raises the voltage output, and very high voltage spikes can occur on transients.

 

The preamp into which that signal goes will either (i) handle that signal or (ii) not be capable of handling that strong of a signal, resulting in distortion. Most acoustic guitar preamps are of poor design in this regard. They have very meek power supplies and the "rail voltage" at which they operate cannot handle the higher voltage spikes.

 

I suspect your Takamine preamp is of this type. It has a 9v power supply (8v rail voltage swing).

 

Recently, both D-TAR and PUTW have released preamps with 18v power supplies. That, along with a higher internal rail voltage swing (about 16v), results in less quack with piezo pickups.

 

Of course, there is one acoustic guitar preamp, around since the early 1990's, that has a 48v rail voltage swing. You simply don't hear quack with this unit. It's the Pendulum Audio SPS-1.

[guitapick]

I cut the mid down a lot with my classical. That helps eliminate a lot of the quack. I've got a Schertler 'David' amp. Has this "warm" button which helps even more.

 

Trouble is that you lose some volume when you turn down the mid.

[RainsongDR1000]

 

Originally posted by sdelsolray Of course, there is one acoustic guitar preamp, around since the early 1990's, that has a 48v rail voltage swing. You simply don't hear quack with this unit. It's the Pendulum Audio SPS-1.

 

 

Yep, Great unit. Ian Anderson uses one, John Mayer, etc....

They are also upwards of $1500. Another one you can try if that's out of your price range is the D-tar Mama Bear:

http://www.d-tar.com/mama_bear.shtml

About $450. It gets rid of most, if not all the quack from what I've heard.

The Fishman Aura is another option and the one I currently use.

I'm quite happy with it and I picked mine up for under $300.

If that's still too much cashola there is this nifty pickup called the "quackbuster" by pick-up the world:

http://www.pick-uptheworld.com/pickups.htm

Go to products>pickups>acoustics steel string guitars and scroll to the bottom. you install it in addition to the pickup in your Tak. I haven't heard one in person but the idea sounds sound and has gotten some good reviews. Thinking of getting one for my Fishman equipped Yamaha, except I just don't gig with it much since getting the Rainsong. Plus, I already have the Aura, so it would be kinda redundant.

[DeepEnd]

"Overdriving the top" generally happens with cedar tops. At a guess, I'd say the issue in your case is probably preamp being overdriven. How new is the battery?

 

As for the stick-on transducer, the Schaller Oyster is similar, as are the K&K Hot Shot and Big Shot. EPM, which makes the pickup systems for Art & Lutherie's also makes something in the same vein. All are commonly available on eBay for around $30.

[Cripes]

 

Originally posted by daklander Dean Markley makes one that is similar and sounds decent.

 

 

These Dean Markley P/U's are not the stick-on types.

[pipedwho]

Originally posted by sdelsolray Piezo-based pickups generate different voltage (and impedance) levels depnding, for example, on how much they are stimulated. Strumming very hard raises the voltage output, and very high voltage spikes can occur on transients. The preamp into which that signal goes will either (i) handle that signal or (ii) not be capable of handling that strong of a signal, resulting in distortion. Most acoustic guitar preamps are of poor design in this regard. They have very meek power supplies and the "rail voltage" at which they operate cannot handle the higher voltage spikes. I suspect your Takamine preamp is of this type. It has a 9v power supply (8v rail voltage swing). Recently, both D-TAR and PUTW have released preamps with 18v power supplies. That, along with a higher internal rail voltage swing (about 16v), results in less quack with piezo pickups. Of course, there is one acoustic guitar preamp, around since the early 1990's, that has a 48v rail voltage swing. You simply don't hear quack with this unit. It's the Pendulum Audio SPS-1.

 

I have a Takamine and have had the same problem. If the pickup adjustment screws are tight, the level can be very high out of the Tak's palathetic pickups. I was getting a swing up to about 5V (peak to peak) when really cranking hard on the guitar. This is huge and since all the Takamine onboard preamps use a class A JFET based preamp stage they only have around 3V of dynamic range.

 

A decent preamp can be made with just a 9V battery, but it is cleaner to use 18V. I've made a pre-preamp circuit to reduce the level of the input signal before feeding it to the onboard preamp, and it really cleans things up.

 

I also use a Takamine Triax (a rebadged black version of LR Baggs M1) with the Cooltube dual input and it works beautifully when blending with the piezos. The Cooltube effect can be used to hide some quack, but it works even better when the quack isn't there in the first place.

[sdelsolray]

 

Originally posted by pipedwho A decent preamp can be made with just a 9V battery, but it is cleaner to use 18V. I've made a pre-preamp circuit to reduce the level of the input signal before feeding it to the onboard preamp, and it really cleans things up.

 

 

Another feature of the Pendulum has is a built-in fixed limiter circuit in the preamp module. The feature is not advertised on the website. Greg, the designer, told me about it.

[daklander]

 

Originally posted by Cripes These Dean Markley P/U's are not the stick-on types.

 

 

Sorry to disagree. My son had one and it was very nice until the cable pulled out of the wooden disc.

From Markley's website on that pickup.

 

Artist Transducer's special mounting adhesive allows the Artist to be mounted and removed many, many times without hurting the finish. The Artist has been on the market for over 17 years and we've never had a complaint about it or the adhesive.

 

[Michael Martin]

 

Originally posted by sdelsolray The preamp into which that signal goes will either (i) handle that signal or (ii) not be capable of handling that strong of a signal, resulting in distortion. Most acoustic guitar preamps are of poor design in this regard. They have very meek power supplies and the "rail voltage" at which they operate cannot handle the higher voltage spikes. I suspect your Takamine preamp is of this type. It has a 9v power supply (8v rail voltage swing).

 

Well, it's powered by a pair of AAs--wouldn't that mean it's only 3 volts? (It's not the preamp that is standard for this Tak--it's the DSP preamp that is programmable and has reverb).

 

And I do replace batteries regularly.

 

Hell, should I ditch the DSP and find something else to put in there? I don't like the damn pushbuttons anyway...nice to have the reverb, but in truth I don't use it much.

[guit30]

You definitely run it thru a preamp like a Baggs Paradi or Tech 21 sansamp, makes a world of difference

Jim

[pipedwho]

Originally posted by Michael Martin Well, it's powered by a pair of AAs--wouldn't that mean it's only 3 volts? (It's not the preamp that is standard for this Tak--it's the DSP preamp that is programmable and has reverb). And I do replace batteries regularly. Hell, should I ditch the DSP and find something else to put in there? I don't like the damn pushbuttons anyway...nice to have the reverb, but in truth I don't use it much.

 

The DSP preamp uses a different input stage, so it has about the same dynamic range as the class-A ones at 9V. I've played with it a bit and didn't think it was too bad (except for the battery life ).

 

I'd keep it. I'm going to try experimenting with the pickup adjustment screws and then a passive reduction circuit to see if I can post a general solution to the problem.

 

BTW, if you use an outboard preamp, you'll need to unplug the piezo from the internal preamp (which is just an RCA jack) and bring it out to something like a PADI as guit30 suggests.

[T.B.]

"The Quack Buster",

PUTW's $60 on-board tone patch. Similar to our Model #27, the Quack Buster is a very easy to install soundboard transducer that is designed to be used with guitars that have existing saddle type pickups installed. As the name implies, the Quack Buster eliminates most if not all of the irritating piezo 'quack' from saddle type pickups, while at the same time adding warmth, depth, and harmonic detail to the signal. At lease that's what they say.

 

http://www.pick-uptheworld.com/pickups.htm

 

 

Trina

 

P.S. I know few players who've sung the Q.B. praises, all had their Guitar Tech's do the installation.

[learn'r]

this is what I'm looking at:

 

one of the trinity systems:

http://www.kksound.com/acousticguitar.html

just wish they had Mic out low impedance.

 

but I guess I can get it here .... heard nothing but good about these:

http://www.shorelinemusic.com/amplification/baggs_padi.shtml

 

sorry still saving up for the transition can't give a user report.

[Cripes]

 

Originally posted by daklander Sorry to disagree. My son had one and it was very nice until the cable pulled out of the wooden disc. From Markley's website on that pickup.

 

 

You're right! Thanks for the double-take. The stick-on is on the very first page of the link. I looked deeper into the site. I'd like to try one of these.

[daklander]

 

Originally posted by Cripes You're right! Thanks for the double-take. The stick-on is on the very first page of the link. I looked deeper into the site. I'd like to try one of these.

 

 

No sweat. I linked directly to that pickup's page.

It did sound very nice and I think it's well worth looking at, especially for the price.

I may end up buying one to use as a backup for my gigs in lieu of the Pro-Mag I carry along because it's probably easier to route the cable out of the way with it than the Pro-Mag..