If it quacks like a duck ....

[JohnW63]

If amp systems with a roll off above certain frequencies work better, as Steve discusses, couldn't you roll off those frequencies with the amp tone controls of a more modern amp to get good results ?

How does the impedance of the preamp vs the input of the amp play into this ? I was thinking of trying both low and high impedance inputs of my amps that have those choices to see if I could here a difference.

[Mandobart]

Originally Posted by JohnW63

How does the impedance of the preamp vs the input of the amp play into this ? I was thinking of trying both low and high impedance inputs of my amps that have those choices to see if I could here a difference.

Impedance mismatch cause a signal phase shift and signal loss/distortion. The signal hits the uneven interface and part gets reflected back while the rest gets shifted.

A good preamp is one way to eliminate the impedance mismatch. The preamp's input matches the piezo output and the preamp output matches the amplifier/PA input. You can achieve the same impedance matching with an active or passive DI, or by using an acoustic amp or PA with a high impedance (HI Z) input channel.

[JLS]

Originally Posted by fazool

Great explanation Picker2.

Piezo quack is probably my greatest guitar pet peeve and one of those sounds that grate on me like dragging fingernails on a chalkboard (while chewing tinfoil). I hate, hate, HATE piezo quack.

I've been to a *lot* of concerts. The worst sound I've ever heard was an acoustic show by my favorite artist because it was all piezo quack - it was so very bad. And he was playing a very well-known piezo guitar.

I just don't understand how anyone can't cringe when they hear it.

I think a SBT piezo is less offensive than a UST piezo and I love a good mic-ed acoustic or a good magpu, but quack is the scourge of the guitar world, to me.

I gave up on USTs about 20 years ago, and began experimenting with SBTs; the ugly, flat tone of USTs, string balance issues, the need to have a less than optimum saddle fit...

[JohnW63]

A good preamp is one way to eliminate the impedance mismatch.

Do you mean the guitar's built in preamp or a preamp in between the guitar and the amp ?

My oldest Ovation has a very simple pre-amp. It only has a volume control. A newer one has EQ features as well.

or by using an acoustic amp or PA with a high impedance (HI Z) input channel.

What would be considered a high Z input ? Do most amp manuals list that number or just simply say " high impedance " in the specs ?

[Mandobart]

Originally Posted by JohnW63

Do you mean the guitar's built in preamp or a preamp in between the guitar and the amp?

Most built in preamps will provide the correct impedance match. However they are of limited quality and can fail over time like anything else. I don't have any instruments with a built in preamp. I've had good success with the lowly Behringer ADI21, K&K Pure preamp and of course Redeye. I also have no instruments with an UST quack-prone pickup. The distortion/overdrive inherent with an UST isn't eliminated with just the proper impedance match.

Originally Posted by JohnW63

What would be considered a high Z input ? Do most amp manuals list that number or just simply say " high impedance " in the specs ?

One to ten megohms is standard impedance for a piezo. My Carvin specs just say "greater then 500 kohm" for the input impedance and it sounds fine with my JJB PPS200 equipped instruments.

[fazool]

Having bought a nylon string Taylor NS32ce, I was interested to learn as much as I can before it arrives. It was a damaged project and looks like a funrepair and I've always enjoyed nylon string guitars.

So, I've watched a number of videos and there is two common things that I have yet to find exception to:

1) These guitars sound fantastic mic-ed.
2) These guitars sound horrifying plugged in.

There is so much quack on every Youtube video I (literally) didn't make it through the songs.

[StevenL]

Most of the quack comes from the attack. A thicker pick with a more rounded picking edge can help a lot with quack attack.

[Paleolith54]

Originally Posted by StevenL

Most of the quack comes from the attack. A thicker pick with a more rounded picking edge can help a lot with quack attack.

And another huge thing here is how hard you hit the strings. I found that a lighter touch (which takes more practice than you think) coupled with not picking too close to the bridge (assuming a UST, of course) made a world of difference.