Tech information on BigTone pickup?

lschwart

I recently bought a used Gitane DG-300 with a Dupont BigTone pickup installed. It came with no technical information, so I was wondering who actually makes this pickup and where on the web I can find information about its specs. (especially it's output impedance).

Thanks in advance for any help!

Louis

MichaelHorowitz

Hi Louis,

There is no "Bigtone" corporation that makes these. Rather, it is just a term used for a Selmer style bridge with a piezo element embedded inside. Many luthiers make them, with Dupont's being the most common.

thanks,

Michael

lschwart

Michael,

Thank you so much! That explains things a little. There's no information about the pickup on Dupont's website, but I sent them an email asking for whatever information they can provide. In the meantime, do you have any recommendations for how to handle the pickup in a signal chain? I've been experimenting with a few different approaches, but haven't settled on anything yet. It has a much stronger signal than the ones that I've experienced coming from passive undersaddle piezos in a typical flattop acoustic. More like the signal that comes from soundboard transducers like the K&K Pure Western Mini, which is also passive, but relatively loud, although it doesn't behave like a K&K, sound and touch-wise. I suspect that, like the K&K, the signal is almost as strong as some active signals, but it still has a high enough impedance that it needs to see a High-Z input (at least 1 megaOhm or more). At least that's what my fumbling around so far has been suggesting.

I'd be grateful for any advice you have!

Louis

pickitjohn

This is from Michaels recommendations and reviews post:

check out link:

viewtopic.php?f=9&t=3850

You may also find some previously posted info in this Thread:

viewtopic.php?f=9&t=11819&hilit=dupont+bridge
Bigtone (and other piezo type systems):






One of the biggest breakthroughs in acoustic guitar amplification has been the introduction of piezo technology. The use of piezo crystals has allowed for a more "acoustic" sounding reproduction of an instrument by providing more dynamics and clarity then magnetic pickups. However, piezo systems usually suffer from tonal problems which can give it a harsh, brittle, and quacky sound. High end acoustic amps and pre amps can considerably improve these problems, but they never totally disappear.



The Good:

High volume output before feed back (especially if installed in the bridge like a Bigtone).

Very present, and clear sound. Rarely muddy or diffuse.

Bigger dynamic range then most other systems.

The Bad:

Quacky, brittle sound. Often very harsh.

Requires expensive modification to guitar (must drill holes and change bridge).

Recommendation

Good for players who need to play lead at high volumes and are willing to accept some brittleness and harshness to do so. Also works well for rhythm players.

Piezos are also the most user friendly....most are just plug and play with little or no extra wires, tweaking, etc.

pick on

pickitjohn

lschwart

Thank you, pickitjohn!

I did read both of those threads before posting, but there was no discussion there of the electronic specs. I'm curious about the output impedance, although I'm guessing from the way my pickup behaves that it's output signal has a pretty high impedance, despite the fact that its strength is comparable to a lot of lower impedance active pickup signals. In any case, I initally tried plugging it into a input designed to take an active signal (no gain, lowish impedance) and while the level was fine, the tone was quite harsh and brittle. Plugging it into a a few different high-Z inputs (either 1 or 10 megaOhms) made a significant difference for the better, although the gain settings on those preamps had to be kept pretty low.

Louis

lschwart

Just an update:

I got an email response from Maurice Dupont, and he confirmed that the the pickup signal, despite its strength, needs to go into a high-z input.

Louis

Al Watsky

No big revelations.
Hi z input.
Your advised to use a buffering preamp of some sort. Any of the usual brands will do.
Some of the harshness you noticed will be gone because the device will act in part as a frequency limiter. Thats one of the design parameters as there are frequencies on both ends of the spectrum coming from any piezo that you do not want to be heard.
So once you have your buffer you have some eq as well.
I think of the many I have seen the K&K unit with vol. and tone. only , is the most compact and sounds fine.
The others the Baggs, Fishman and etc have graphic eq and other features.
Any of these will make a Bigtone sound better.

lschwart

Al Watsky wrote:

No big revelations.
Hi z input.
Your advised to use a buffering preamp of some sort. Any of the usual brands will do.
Some of the harshness you noticed will be gone because the device will act in part as a frequency limiter. Thats one of the design parameters as there are frequencies on both ends of the spectrum coming from any piezo that you do not want to be heard.
So once you have your buffer you have some eq as well.
I think of the many I have seen the K&K unit with vol. and tone. only , is the most compact and sounds fine.
The others the Baggs, Fishman and etc have graphic eq and other features.
Any of these will make a Bigtone sound better.

Yup!

Works very nicely with my Baggs PADI, my Radial PZ-Pre (with PZ switch engaged), but also through my Fishman AFX reverb, which has a 1 megaOhm input impedance and acts as a buffer, then from there to a DI and into the mixer. Or, as you'd expect, into one of the high-z inputs of my ZED10FX. The pickup doesn't need a preamp other than the one in on the channel of a mixer (or the input of a combo amp). But it does need a buffer before getting to any low-z imputs.

Louis