Piezo wiring w/ tone & volume

[nbtone]

The old preamp had one tone control. The tube preamp is my design. www.nitewalkerpreamp.com. It makes a big difference. I just need to get the two controls on the instrument to work right.

I think what you actually don't like is the tone of the pickup. Or maybe the preamp was just cheap. A good piezo preamp can make a big difference, but if the pickup is quacky, you need a different pickup. A god preamp would at least let you EQ the tone better.

The tube preamp is doing the same thing as the old preamp. Did the old internal preamp have tone controls?

[slbarton]

I can't see the circuit diagram, could you please re-post it?

Thanks!

[Mark Hammer]

I'm still not sure what the advantage of having them in series might be. In the case of mag pickups, placing two coils in series changes the inductance and overall tone as a result. But placing two piezo sensors in series does not do that. Indeed,the whole point of using a piezo sensor is to provide a faithful replica of the acoustic sound, and the whole point of using multiple piezo sensors is to provide a balanced acoustic sound.

Seems to me like recommendations for a parallel arrangement, with some means for balancing levels is the optimum.

[David Schwab]

The old preamp had one tone control. The tube preamp is my design. www.nitewalkerpreamp.com. It makes a big difference. I just need to get the two controls on the instrument to work right.

If you have the tube preamp replacing the internal preamp, why do you need passive controls? It's redundant.

A better quality internal preamp would have done the trick also. The real problem is likely a poor quality transducer. The tubes just smooth that quackyness out.

[bbsailor]

Hello. I'm building an upright bass & plan to put 2 piezo's in series wired to volume & tone pots. Below is the diagram i am using. Does it look correct? Also, what type/Ohm pots would you suggest.







Thanks,
-Jack

Jack,

Check out J. Donald Tillman's web site. http://www.till.com/articles/GuitarPreamp/index.html

Use a 50K pot in place of the 50K load resistor on the output and take the output from the wolume pot's center lug with a capacitor going to a tone pot of about 50K also.

Use a stereo jack so when you attach the .25" plug cable, you turn on the 9V battery.

Buy a few JFETS as they have a wide variation. See his web page for details about this.

You should be able to whip this up on a small perf board with point-to-point soldering and make a pretty small package to mount inside the bass or in a small box to mount on the bass so you don't need to put any holes in your bass. Use 1/8 watt resistors. Most parts are available at Radio Shack.

I hope this points you in the right direction?

Joseph Rogowski

[nbtone]

I need to have a control I can get to fast. Active pots sound too synthetic. The tube makes for a richer, more natural sounding instrument. The piezo pickups work very well with gut strings, too.

If you have the tube preamp replacing the internal preamp, why do you need passive controls? It's redundant.

A better quality internal preamp would have done the trick also. The real problem is likely a poor quality transducer. The tubes just smooth that quackyness out.

[David Schwab]

I need to have a control I can get to fast. Active pots sound too synthetic. The tube makes for a richer, more natural sounding instrument. The piezo pickups work very well with gut strings, too.

I'm sorry ... what's an "active pot"? That's just dumb sounding. Tubes are active also. Pots are passive devices. Tubes are not more "natural" sounding, they color the tone, especially if you are running them at a low voltage starved plate condition. Your tube preamp is EQing the tone to sound more natueral. You can get a solid state device to do that too.. like the D/Tar systems. Or a good piezo pickup from someone like RMC.

And yes, I have a 500 Watt all tube amp (Mesa 400+), and I like solid state better for bass instruments requiring a clean tone, and tubes better for guitar.

The problem is that piezo pickups don't sound like the instrument does acoustically. It has nothing to do with an "active pot"... what ever the heck that is supposed to be. And it's not the piezos fault. The transducer is only picking up the tone of the string at the bridge, but that's not what you hear on an acoustic instrument. If you press your ear on the bridge and bow, it will sound like the piezo. Bowed strings vibrate side to side, while the sound board wants to vibrate up and down. So the piezo is not sensing the correct vibrations of the strings. Ned Steinberger has a good system to help that along by using two piezos mounted at right angles.

A preamp is a preamp. Doesn't matter if it uses tubes, bipolar transitors, jfets or op amps.

[nbtone]

OK, maybe I'm not using correct English to explain myself. "Active pots" are a term that has been used for bass guitar players that means the guitar has a pot that is switchable between "active" and "passive". Usually you have to pull the volume control out to get to the active position. "Active" means there is a solid state preamp that runs off of a 9v battery engaged. Many electric cellos use "active" electronics. Maybe tubes are "active", but I've never seen them switchable from the volume control on the bass.
These solid state devices that you are referring to have no bottom end. There is just no response. Somehow they are getting the bass to respond well in the studio at times, but in live situations once the volume reaches the level needed to play with a set of drums the bass becomes distorted.
NS cellos are certainly nice to dream about if you have that kind of money to spend, but a simple tube preamp with a piezo pickup will do the job. (Better in my opinion) If you can't make one on your own for a few dollars buy one of mine already built and tested. www.nitewalkerpreamp.com.
I may not be the worlds most expert electronics genius, but I've applied for a patent on my bass register musical instrument preamp. I graduated from Berklee College of Music, so my best side is knowing when tone is working and when it isn't. If it's too embarassing to perform in a live situation because the bass sounds empty or distorted, maybe its best to leave the performing to the beginners???

I'm sorry ... what's an "active pot"? That's just dumb sounding. Tubes are active also. Pots are passive devices. Tubes are not more "natural" sounding, they color the tone, especially if you are running them at a low voltage starved plate condition. Your tube preamp is EQing the tone to sound more natueral. You can get a solid state device to do that too.. like the D/Tar systems. Or a good piezo pickup from someone like RMC.

And yes, I have a 500 Watt all tube amp (Mesa 400+), and I like solid state better for bass instruments requiring a clean tone, and tubes better for guitar.

The problem is that piezo pickups don't sound like the instrument does acoustically. It has nothing to do with an "active pot"... what ever the heck that is supposed to be. And it's not the piezos fault. The transducer is only picking up the tone of the string at the bridge, but that's not what you hear on an acoustic instrument. If you press your ear on the bridge and bow, it will sound like the piezo. Bowed strings vibrate side to side, while the sound board wants to vibrate up and down. So the piezo is not sensing the correct vibrations of the strings. Ned Steinberger has a good system to help that along by using two piezos mounted at right angles.

A preamp is a preamp. Doesn't matter if it uses tubes, bipolar transitors, jfets or op amps.

[David Schwab]

Yes, I know what an active preamp is, I was referring to an "active pot", since preamps don't need to have a control of any kind.

Perhaps the lack of bass response is something to do with bowed instruments, because that's certainly not the case with active electric basses, and not with any upright basses with piezos I've heard, unless they have no impedance matching preamp. Then they sound scratchy and shrill.

Basically what NS does is to use two piezo pickups at 90° angles to each other.

I use solid state preamps in my electric basses and they have great low frequency response. I also have a tube preamp pedal, and that does give the effect of "warming" up the tone, but it isn't adding any low end that isn't already there.

I've made a lot of DC coupled JFET preamps that give wonderful low end... all the way down to DC.

Piezos can sound quacky, especially under saddle units. So I can see where a tube might smooth things out, but the fault was the pickup to start with, not the "active pot".

[nbtone]

OK, OK Here is the link to the pateent info. I'm sorry if I disagree with you on the topic of tone quality for basss register musical instruments: http://www.google.com/patents?id=4gG...ord+w.+latshaw

Yes, I know what an active preamp is, I was referring to an "active pot", since preamps don't need to have a control of any kind.

Perhaps the lack of bass response is something to do with bowed instruments, because that's certainly not the case with active electric basses, and not with any upright basses with piezos I've heard, unless they have no impedance matching preamp. Then they sound scratchy and shrill.

Basically what NS does is to use two piezo pickups at 90° angles to each other.

I use solid state preamps in my electric basses and they have great low frequency response. I also have a tube preamp pedal, and that does give the effect of "warming" up the tone, but it isn't adding any low end that isn't already there.

I've made a lot of DC coupled JFET preamps that give wonderful low end... all the way down to DC.

Piezos can sound quacky, especially under saddle units. So I can see where a tube might smooth things out, but the fault was the pickup to start with, not the "active pot".

[David Schwab]

OK, OK Here is the link to the pateent info. I'm sorry if I disagree with you on the topic of tone quality for basss register musical instruments: http://www.google.com/patents?id=4gG...ord+w.+latshaw

And so how is this different from, say the Tube Works Blue Tube I have? Besides the lack of adjustable EQ I don't see where you are doing something new. You have some fixed EQ going on, so this certainly does not reproduce the pickup accurately, but then that's what you are after. And piezo pickups need EQ.

There are a lot of tube preamps for bass out there. I personally prefer solid state preamps as tubes are too slow in response for me, and as I mentioned I have a very big all tube amp that I never use. Tubes feel mushy, and I don't care for that, though they do sound warm.

This whole thread seems like it was really just thinly veiled advertising for your preamp.

[nbtone]

I'm not personally familiar with the Tube Works Blue Tube that you mention, but I'm sure it's something along the lines of the ART Tube Bass preamps that came out a few years back. I started out really liking to play bass guitar, but lost interest when my tone control wouldn't work anymore. That happened when I bought a new amp in 1968. My first amp was from the 50's, and the tone at a low volume was what I liked. Turn it up, and it would distort, though. I've bought several more since then, and nothing works for me. I experimented alot with parts from stripped church organs, and I found a way to recreate the sound that I liked when I was young, even through solid state bass amps. Now the tone control on my bass guitar "works" again.
Warm doesn't do much for me. I like a musically richer tone from a musical instrument. Solid state amps save electricity, and they sound real good. I like tube amps better, though. If you do try to build one of these circuits make sure you use the correct voltage for the paper in oil caps. I think they are rated at 500 or 600vdc, when the circuit is only operating at about 50 vdc. The tone doesn't change if you try using lower voltage rated caps.

And so how is this different from, say the Tube Works Blue Tube I have? Besides the lack of adjustable EQ I don't see where you are doing something new. You have some fixed EQ going on, so this certainly does not reproduce the pickup accurately, but then that's what you are after. And piezo pickups need EQ.

There are a lot of tube preamps for bass out there. I personally prefer solid state preamps as tubes are too slow in response for me, and as I mentioned I have a very big all tube amp that I never use. Tubes feel mushy, and I don't care for that, though they do sound warm.

This whole thread seems like it was really just thinly veiled advertising for your preamp.

[Dave Kerr]

This whole thread seems like it was really just thinly veiled advertising for your preamp.

Ya think?