Need help not wasting money - need amp for upright with piezo

[DJ Bebop]

After the piezo pickup and preamp are worked out, you might to also try an IR loader or software and some good DB IRs
Upright Basses Archives - 3 Sigma Audio
These can really add back "body" to your sound that the piezo misses.

Somewhat unrelated but I've used a DB body sim from Zoom in their Guitar Lab to add a more open sound to an Acoustic 360 model to get the cab to sound more 361 ish.

 

[Billgore]

Wanted to chime back in with an update.

Found a fender rumble 100 on reverb barely used. Unboxed, plugged in with instrument cable to piezo directly, set all knobs at 12 o clock, fired it up and it sounded great. No audible noise or feedback. Can eq in some slight improvement to clarity and db character. But for my purpose I wouldn't change a thing. It states 1MOhm input impedance.

It's incredible how light the amp is. I guess that's the class d power amp. Plenty loud to keep up with the drum set with plenty of headroom.

Tech has come a long way since last time I was buying gear like this.

 

[agedhorse]

Good to hear that the results were satisfactory.

 

[thmsjordan]

Yes, the early Underwood pickups were often used with amps having an input impedance of less than 1Meg, so a buffer was beneficial. Since the crystals are quite small inside the brass wings, there was a lot of benefit to buffering with those amps.

Since many amps these days are 1Meg or greater, there is much less benefit to a higher input impedance, and there is significant drawbacks with regard to noise (cable and circuit) as well as RF interference (especially close to RF sources such as radio transmitters).

I was working on pro audio and acoustic products (specifically active direct boxes and pick-up systems for acoustic instruments) around the time that the Underwood pickups became popular, Don's mechanical design was the first practical design for bass guitars (also used on cellos and even viola/violin) because it was easy to install. They did suffer from a lot of broken crystals because players couldn't follow the installation and handling instructions though. Underwood was another San Francisco Bay Area company that pushed the industry forward, this was a great (and fun) time to be working in audio. The fact that they are still relatively popular is a testament to the quality of the basic design.

Yes, I still use Underwood after trying many more expensive options. Last I checked, Stanley Clarke was still using them as well but that was at least 6 years ago.

 

[banjackal]

Wanted to chime back in with an update.

Found a fender rumble 100 on reverb barely used. Unboxed, plugged in with instrument cable to piezo directly, set all knobs at 12 o clock, fired it up and it sounded great. No audible noise or feedback. Can eq in some slight improvement to clarity and db character. But for my purpose I wouldn't change a thing. It states 1MOhm input impedance.

It's incredible how light the amp is. I guess that's the class d power amp. Plenty loud to keep up with the drum set with plenty of headroom.

Tech has come a long way since last time I was buying gear like this.

IME I've had to take a lot (or all) of the lows and low mids down on my rumble 500 to prevent feedback in live situations. However, I'm also using a realist pickup which ofc are known to be bassier, so ymmv.
Just my $0.02. enjoy!