Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Preamps and Effects => Topic started by: tonyharker on October 29, 2020, 05:14:43 PM

Title: Piezo Preamp
Post by: tonyharker on October 29, 2020, 05:14:43 PM
 Has anyone tried to use one of those Piezo preamps sold for ukuleles like this on Ali Express https://www.aliexpress.com/item/33048124904.html?spm=a2g0o.cart.0.0.5e793c00tS3Zyw&mp=1 on a magnetic pickup?

Title: Re: Piezo Preamp
Post by: phatt on October 30, 2020, 04:38:22 AM
Just be aware that most piezo preamps often come with high Freq compensation as piezo elements work all the way past audio freq. Without that in place acoustic guitar can sound really cheap. Scratchy sound,, yuk

As to mag PU it's anyone's guess as to the outcome,,I'd say suck it and see what happens.
Keep us posted if you try it :tu:
Phil.
Title: Re: Piezo Preamp
Post by: GBarry on November 18, 2020, 04:48:53 PM
New here, btw.  hi, everyone!
  I personally haven't used THAT preamp...but my experience is very detailed and lengthy with playing an acousticl loudly thru a P.A.
I play professionally for many years.    In my experience, no Piezo captures an acoustic signal accurately.  They tend to emphasize the high frequencies from 1k-10k....so tiny. "honky", plasticy..are adjectives that are often heard.
    At similar cost..I would consider a contact microphone,instead.  Like the ones used on telephones.  Cheap, and once equalized ,more likely to sound authentic.  But hey, all the technology is cheap..so experiement.
      George
Title: Re: Piezo Preamp
Post by: phatt on November 19, 2020, 06:15:49 AM
Hi George and welcome.  :)
I do agree that ceramic pu and associated preamp designs for acoustic guitar is a hit and miss affair.
Any novice buying new will struggle as there are just so many differing designs used.
There is no standard when it comes to Freq Response and output levels, Some Active piezo systems have insane output levels and are the most likely to squeal or blast out subsonic feedback. xP
Sadly a lot of guitar factories just wack in whatever they can source and never bother to do any R&D as long as they pass signal they go out to retail shops.
Even some expensive systems do sound way too harsh.

As to contact systems, What exactly are you referring to when you say Contact Microphone from telephone?
The ones I've dealt with tend to have feedback issues.
I'm always open to new ideas.

As to preamp design for piezo PU's this might interest you and others who wish to experiment.
https://sound-au.com/project202.htm
Regards, Phil.