Passive tone control for a piezo - Cigar Box Nation2024-03-28T14:55:07Zhttps://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346534&x=1&feed=yes&xn_auth=noSorry...don't see any sales h…tag:www.cigarboxnation.com,2010-11-03:2592684:Comment:3465342010-11-03T06:49:45.841ZGlenn Reitherhttps://www.cigarboxnation.com/profile/GlennReither
Sorry...don't see any sales hype there. Anyhoo, just passing on something that might be interesting to someone. I'm going to try this sometime as a mid cut.<br />
<br />
<br></br>
<br></br>
<cite>jim said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346529&xg_source=msg_com_forum#2592684Comment346529"><div>chasing a headless chicken to train it to sing blues! sooo much bs with a mix of sales hipe…</div>
</blockquote>
Sorry...don't see any sales hype there. Anyhoo, just passing on something that might be interesting to someone. I'm going to try this sometime as a mid cut.<br />
<br />
<br/>
<br/>
<cite>jim said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346529&xg_source=msg_com_forum#2592684Comment346529"><div>chasing a headless chicken to train it to sing blues! sooo much bs with a mix of sales hipe might help! haa<br/> <br/>
<br/>
<cite>Glenn Reither said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346519&xg_source=activity&groupId=2592684%3AGroup%3A153908#2592684Comment346519"><div>Here's another bit of useful passive piezo tone info, using a passive RLC notch filter. I haven't tried this but if you found the right values you could notch out harsh upper-mids, maybe on a toggle switch?<br/> <br/> "Hi, just saw your artical on your $8<br/>
"Doodle-Bass" and noticed you were wanting to<br/>
add an acoustic pickup for it from Radio Shack<br/>
parts.<br/>
<br/>
I am currently working on an instrument I call a<br/>
Bungee Bass that uses rubber strings (actually<br/>
"O" ring material). Anyway, I have used a very<br/>
cheap transducer system on several of my<br/>
home-made instruments that you may find useful.<br/>
<br/>
Basically, all you need is a Radio Shack 273-073<br/>
Piezo Transducer and an output jack. If the<br/>
instrument puts out any acoustic sound at all,<br/>
it will pick it up, you just need to find the<br/>
"sweet spot" to mount it. You (in most cases)<br/>
don't even need a preamp or power (battery)<br/>
<br/>
The trouble with this $1.49 transducer as<br/>
opposed to a $90. 00 and up "pro" modle is that<br/>
is quite "trebley" making you turn the treble<br/>
down on the amp. But once you do that, it makes<br/>
an acoustic guitar sound just as good as to<br/>
"pro" transducers.<br/>
<br/>
A solution for this is a passive filter known as<br/>
an RLC Notch Filter. "Passive" means it needs no<br/>
external power and "RLC" means a Resistor, Load<br/>
(inductor) and Capacitor. "Notch" means it will<br/>
notch out a frequency and shunt it to ground.<br/>
The circuit does not even need to be mounted on<br/>
a PC board ( but shielding it in some cardboard<br/>
covered in aluminium foil tape is a good idea as<br/>
well as using shielded wire). The drawback for<br/>
passive filters is some overall volume loss.<br/>
<br/>
If all the components are "tuned" very tightly<br/>
(very low Q) the notch would be very slim. This<br/>
is kind of hard to do because of the<br/>
availability of the components, fortunatly, we<br/>
are better of with a wide notch. So wide, in<br/>
fact, that it virtually becomes a low-pass (or<br/>
high-pass) filter becuase of the audable range<br/>
of human hearing.<br/>
<br/>
I could bore you with a lot of math formula but<br/>
the following diagram and parts list will be all<br/>
you will ever need.<br/>
<br/>
<br/>
Black Lead --------------------------------->Output Jack Ground<br/>
(T1)<br/>
Red Lead ----->R1>----->----------------->Output Jack Tip<br/>
|<br/>
|<br/>
>C1>--->L1>--->Output Jack Ground<br/>
<br/>
Parts List for a Bass Transducer System:<br/>
<br/>
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br/>
<br/>
R1 = 33 ohm resistor<br/>
<br/>
C1 = .0047 uF capacitor<br/>
<br/>
L1 = 156 uH inductor<br/>
<br/>
The L1 - 156 uH inductor it's part of the Radio<br/>
Shack Inductor Assortment - Cat# 273-1601 ($2.<br/>
49). You can easly identify it as it is Light<br/>
Blue, looks sort of like a capacitor and has a<br/>
Brown dot on one side, a Blue dot and a Green<br/>
dot on top, and a Gold dot on the other side<br/>
<br/>
<br/>
Parts List for a Guitar/Banjo Transducer System:<br/>
<br/>
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br/>
<br/>
R1 = 33 ohm resistor<br/>
<br/>
C1 = .0022 uF (microfarad) capacitor<br/>
<br/>
L1 = 602 uH (microhenry) inductor<br/>
<br/>
The L1 - 602 uH inductor it's part of the Radio<br/>
Shack Inductor Assortment - Cat# 273-1601 ($2.<br/>
49). You can easly identify it as it is Light<br/>
Green, looks sort of like a little dumbbell and<br/>
has "602" on it's top.<br/>
<br/>
<br/>
Construction Notes:<br/>
<br/>
1. I usually remove (carefully) the black<br/>
plastic mounting shell from the transducer.<br/>
Then, I'll tape the transducer to different<br/>
mounting locations until I find the "sweet<br/>
spot". Once I have that, I glue the transucer in<br/>
place.<br/>
<br/>
2. It makes no difference if the black wire from<br/>
the transducer stops to hook to the ground of<br/>
the filter before continuing to the output jack.<br/>
The diagram shows it otherwise for clearity.<br/>
<br/>
3. If you need to use a preamp (as I do on the<br/>
rubber string bass) then make R1 = 3.3k omhs.<br/>
The preamp should "sit" between the RS 273-073<br/>
and the filter.<br/>
<br/>
4. You can make a "depth control" using the<br/>
following diagram:<br/>
<br/>
<br/>
Black Lead ------------------------------->Output Jack Ground<br/>
(RS 273-073)<br/>
Red Lead ----->R1>--->----------------->Output Jack Tip<br/>
|<br/>
|<br/>
>C1>-->H1>-->R2>-->Output Jack Ground<br/>
<br/>
R2 = 50k ohm audio taper potentiometer (linear will do)<br/>
<br/>
The pot has 3 terminals, terminal 1 connects to<br/>
H1 and terminals 2 and 3 go to ground.<br/>
<br/>
This control will travel from full filter to<br/>
complete elimination of the filter fom the<br/>
circuit.<br/>
<br/>
5. If you have an assortment of caps, you can<br/>
change the notch to "flavor" the instrument by<br/>
experimenting with various values. You can also<br/>
try other inductor/cap combinations and even<br/>
change the resistors value BUT... the source<br/>
(driving) impedance should be LOWER than the<br/>
impedance of the filter. Also, the output of the<br/>
filter should feed an impedance (amplifier) much<br/>
HIGHER than the filter impedance.<br/>
<br/>
<br/>
All and all, I have found this a very good<br/>
sounding transducer especially at the price. If<br/>
you put this on a nice acoustic guitar, the<br/>
end-pin jack would cost you more than the<br/>
transducer system.<br/>
<br/>
Well, I hope this info will prove useful to you<br/>
and I'll keep an eye on your page, which has<br/>
provided me with alot of ideas on my own<br/>
projects.<br/>
<br/>
Thanks Clark Rowden"<br/>
<br/>
<br/>
<br/>
<br/>
<cite>Don Thompson said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment256224"><div>Yep, My guess is a much larger value for the tone pot. On the order of 1Meg or more. Piezos simply do not have the same electrical values as a magnetic pickup so what works for one won't work for the other. Don<br/> <br/> <cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A256201&xg_source=msg_com_forum#2592684Comment256201"><div>I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br/>Id be interested as to what you find in there - could be a leprechaun!</div>
</blockquote>
</div>
</blockquote>
</div>
</blockquote>
</div>
</blockquote> chasing a headless chicken to…tag:www.cigarboxnation.com,2010-11-03:2592684:Comment:3465292010-11-03T06:36:35.544Zjimhttps://www.cigarboxnation.com/profile/jim
chasing a headless chicken to train it to sing blues! sooo much bs with a mix of sales hipe might help! haa<br />
<br></br>
<br></br>
<cite>Glenn Reither said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346519&xg_source=activity&groupId=2592684%3AGroup%3A153908#2592684Comment346519"><div>Here's another bit of useful passive piezo tone info, using a passive RLC notch filter. I haven't…</div>
</blockquote>
chasing a headless chicken to train it to sing blues! sooo much bs with a mix of sales hipe might help! haa<br />
<br/>
<br/>
<cite>Glenn Reither said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A346519&xg_source=activity&groupId=2592684%3AGroup%3A153908#2592684Comment346519"><div>Here's another bit of useful passive piezo tone info, using a passive RLC notch filter. I haven't tried this but if you found the right values you could notch out harsh upper-mids, maybe on a toggle switch?<br/> <br/>
"Hi, just saw your artical on your $8<br/>
"Doodle-Bass" and noticed you were wanting to<br/>
add an acoustic pickup for it from Radio Shack<br/>
parts.<br/>
<br/>
I am currently working on an instrument I call a<br/>
Bungee Bass that uses rubber strings (actually<br/>
"O" ring material). Anyway, I have used a very<br/>
cheap transducer system on several of my<br/>
home-made instruments that you may find useful.<br/>
<br/>
Basically, all you need is a Radio Shack 273-073<br/>
Piezo Transducer and an output jack. If the<br/>
instrument puts out any acoustic sound at all,<br/>
it will pick it up, you just need to find the<br/>
"sweet spot" to mount it. You (in most cases)<br/>
don't even need a preamp or power (battery)<br/>
<br/>
The trouble with this $1.49 transducer as<br/>
opposed to a $90. 00 and up "pro" modle is that<br/>
is quite "trebley" making you turn the treble<br/>
down on the amp. But once you do that, it makes<br/>
an acoustic guitar sound just as good as to<br/>
"pro" transducers.<br/>
<br/>
A solution for this is a passive filter known as<br/>
an RLC Notch Filter. "Passive" means it needs no<br/>
external power and "RLC" means a Resistor, Load<br/>
(inductor) and Capacitor. "Notch" means it will<br/>
notch out a frequency and shunt it to ground.<br/>
The circuit does not even need to be mounted on<br/>
a PC board ( but shielding it in some cardboard<br/>
covered in aluminium foil tape is a good idea as<br/>
well as using shielded wire). The drawback for<br/>
passive filters is some overall volume loss.<br/>
<br/>
If all the components are "tuned" very tightly<br/>
(very low Q) the notch would be very slim. This<br/>
is kind of hard to do because of the<br/>
availability of the components, fortunatly, we<br/>
are better of with a wide notch. So wide, in<br/>
fact, that it virtually becomes a low-pass (or<br/>
high-pass) filter becuase of the audable range<br/>
of human hearing.<br/>
<br/>
I could bore you with a lot of math formula but<br/>
the following diagram and parts list will be all<br/>
you will ever need.<br/>
<br/>
<br/>
Black Lead --------------------------------->Output Jack Ground<br/>
(T1)<br/>
Red Lead ----->R1>----->----------------->Output Jack Tip<br/>
|<br/>
|<br/>
>C1>--->L1>--->Output Jack Ground<br/>
<br/>
Parts List for a Bass Transducer System:<br/>
<br/>
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br/>
<br/>
R1 = 33 ohm resistor<br/>
<br/>
C1 = .0047 uF capacitor<br/>
<br/>
L1 = 156 uH inductor<br/>
<br/>
The L1 - 156 uH inductor it's part of the Radio<br/>
Shack Inductor Assortment - Cat# 273-1601 ($2.<br/>
49). You can easly identify it as it is Light<br/>
Blue, looks sort of like a capacitor and has a<br/>
Brown dot on one side, a Blue dot and a Green<br/>
dot on top, and a Gold dot on the other side<br/>
<br/>
<br/>
Parts List for a Guitar/Banjo Transducer System:<br/>
<br/>
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br/>
<br/>
R1 = 33 ohm resistor<br/>
<br/>
C1 = .0022 uF (microfarad) capacitor<br/>
<br/>
L1 = 602 uH (microhenry) inductor<br/>
<br/>
The L1 - 602 uH inductor it's part of the Radio<br/>
Shack Inductor Assortment - Cat# 273-1601 ($2.<br/>
49). You can easly identify it as it is Light<br/>
Green, looks sort of like a little dumbbell and<br/>
has "602" on it's top.<br/>
<br/>
<br/>
Construction Notes:<br/>
<br/>
1. I usually remove (carefully) the black<br/>
plastic mounting shell from the transducer.<br/>
Then, I'll tape the transducer to different<br/>
mounting locations until I find the "sweet<br/>
spot". Once I have that, I glue the transucer in<br/>
place.<br/>
<br/>
2. It makes no difference if the black wire from<br/>
the transducer stops to hook to the ground of<br/>
the filter before continuing to the output jack.<br/>
The diagram shows it otherwise for clearity.<br/>
<br/>
3. If you need to use a preamp (as I do on the<br/>
rubber string bass) then make R1 = 3.3k omhs.<br/>
The preamp should "sit" between the RS 273-073<br/>
and the filter.<br/>
<br/>
4. You can make a "depth control" using the<br/>
following diagram:<br/>
<br/>
<br/>
Black Lead ------------------------------->Output Jack Ground<br/>
(RS 273-073)<br/>
Red Lead ----->R1>--->----------------->Output Jack Tip<br/>
|<br/>
|<br/>
>C1>-->H1>-->R2>-->Output Jack Ground<br/>
<br/>
R2 = 50k ohm audio taper potentiometer (linear will do)<br/>
<br/>
The pot has 3 terminals, terminal 1 connects to<br/>
H1 and terminals 2 and 3 go to ground.<br/>
<br/>
This control will travel from full filter to<br/>
complete elimination of the filter fom the<br/>
circuit.<br/>
<br/>
5. If you have an assortment of caps, you can<br/>
change the notch to "flavor" the instrument by<br/>
experimenting with various values. You can also<br/>
try other inductor/cap combinations and even<br/>
change the resistors value BUT... the source<br/>
(driving) impedance should be LOWER than the<br/>
impedance of the filter. Also, the output of the<br/>
filter should feed an impedance (amplifier) much<br/>
HIGHER than the filter impedance.<br/>
<br/>
<br/>
All and all, I have found this a very good<br/>
sounding transducer especially at the price. If<br/>
you put this on a nice acoustic guitar, the<br/>
end-pin jack would cost you more than the<br/>
transducer system.<br/>
<br/>
Well, I hope this info will prove useful to you<br/>
and I'll keep an eye on your page, which has<br/>
provided me with alot of ideas on my own<br/>
projects.<br/>
<br/>
Thanks Clark Rowden"<br/>
<br/>
<br/>
<br/>
<br/>
<cite>Don Thompson said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment256224"><div>Yep, My guess is a much larger value for the tone pot. On the order of 1Meg or more. Piezos simply do not have the same electrical values as a magnetic pickup so what works for one won't work for the other. Don<br/> <br/> <cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A256201&xg_source=msg_com_forum#2592684Comment256201"><div>I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br/>Id be interested as to what you find in there - could be a leprechaun!</div>
</blockquote>
</div>
</blockquote>
</div>
</blockquote> Here's another bit of useful…tag:www.cigarboxnation.com,2010-11-03:2592684:Comment:3465192010-11-03T06:03:13.871ZGlenn Reitherhttps://www.cigarboxnation.com/profile/GlennReither
Here's another bit of useful passive piezo tone info, using a passive RLC notch filter. I haven't tried this but if you found the right values you could notch out harsh upper-mids, maybe on a toggle switch?<br />
<br />
"Hi, just saw your artical on your $8<br />
"Doodle-Bass" and noticed you were wanting to<br />
add an acoustic pickup for it from Radio Shack<br />
parts.<br />
<br />
I am currently working on an instrument I call a<br />
Bungee Bass that uses rubber strings (actually<br />
"O" ring material). Anyway, I have used a very<br />
cheap…
Here's another bit of useful passive piezo tone info, using a passive RLC notch filter. I haven't tried this but if you found the right values you could notch out harsh upper-mids, maybe on a toggle switch?<br />
<br />
"Hi, just saw your artical on your $8<br />
"Doodle-Bass" and noticed you were wanting to<br />
add an acoustic pickup for it from Radio Shack<br />
parts.<br />
<br />
I am currently working on an instrument I call a<br />
Bungee Bass that uses rubber strings (actually<br />
"O" ring material). Anyway, I have used a very<br />
cheap transducer system on several of my<br />
home-made instruments that you may find useful.<br />
<br />
Basically, all you need is a Radio Shack 273-073<br />
Piezo Transducer and an output jack. If the<br />
instrument puts out any acoustic sound at all,<br />
it will pick it up, you just need to find the<br />
"sweet spot" to mount it. You (in most cases)<br />
don't even need a preamp or power (battery)<br />
<br />
The trouble with this $1.49 transducer as<br />
opposed to a $90. 00 and up "pro" modle is that<br />
is quite "trebley" making you turn the treble<br />
down on the amp. But once you do that, it makes<br />
an acoustic guitar sound just as good as to<br />
"pro" transducers.<br />
<br />
A solution for this is a passive filter known as<br />
an RLC Notch Filter. "Passive" means it needs no<br />
external power and "RLC" means a Resistor, Load<br />
(inductor) and Capacitor. "Notch" means it will<br />
notch out a frequency and shunt it to ground.<br />
The circuit does not even need to be mounted on<br />
a PC board ( but shielding it in some cardboard<br />
covered in aluminium foil tape is a good idea as<br />
well as using shielded wire). The drawback for<br />
passive filters is some overall volume loss.<br />
<br />
If all the components are "tuned" very tightly<br />
(very low Q) the notch would be very slim. This<br />
is kind of hard to do because of the<br />
availability of the components, fortunatly, we<br />
are better of with a wide notch. So wide, in<br />
fact, that it virtually becomes a low-pass (or<br />
high-pass) filter becuase of the audable range<br />
of human hearing.<br />
<br />
I could bore you with a lot of math formula but<br />
the following diagram and parts list will be all<br />
you will ever need.<br />
<br />
<br />
Black Lead --------------------------------->Output Jack Ground<br />
(T1)<br />
Red Lead ----->R1>----->----------------->Output Jack Tip<br />
|<br />
|<br />
>C1>--->L1>--->Output Jack Ground<br />
<br />
Parts List for a Bass Transducer System:<br />
<br />
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br />
<br />
R1 = 33 ohm resistor<br />
<br />
C1 = .0047 uF capacitor<br />
<br />
L1 = 156 uH inductor<br />
<br />
The L1 - 156 uH inductor it's part of the Radio<br />
Shack Inductor Assortment - Cat# 273-1601 ($2.<br />
49). You can easly identify it as it is Light<br />
Blue, looks sort of like a capacitor and has a<br />
Brown dot on one side, a Blue dot and a Green<br />
dot on top, and a Gold dot on the other side<br />
<br />
<br />
Parts List for a Guitar/Banjo Transducer System:<br />
<br />
T1 = Radio Shack Piezo Transducer - Cat# 273-073<br />
<br />
R1 = 33 ohm resistor<br />
<br />
C1 = .0022 uF (microfarad) capacitor<br />
<br />
L1 = 602 uH (microhenry) inductor<br />
<br />
The L1 - 602 uH inductor it's part of the Radio<br />
Shack Inductor Assortment - Cat# 273-1601 ($2.<br />
49). You can easly identify it as it is Light<br />
Green, looks sort of like a little dumbbell and<br />
has "602" on it's top.<br />
<br />
<br />
Construction Notes:<br />
<br />
1. I usually remove (carefully) the black<br />
plastic mounting shell from the transducer.<br />
Then, I'll tape the transducer to different<br />
mounting locations until I find the "sweet<br />
spot". Once I have that, I glue the transucer in<br />
place.<br />
<br />
2. It makes no difference if the black wire from<br />
the transducer stops to hook to the ground of<br />
the filter before continuing to the output jack.<br />
The diagram shows it otherwise for clearity.<br />
<br />
3. If you need to use a preamp (as I do on the<br />
rubber string bass) then make R1 = 3.3k omhs.<br />
The preamp should "sit" between the RS 273-073<br />
and the filter.<br />
<br />
4. You can make a "depth control" using the<br />
following diagram:<br />
<br />
<br />
Black Lead ------------------------------->Output Jack Ground<br />
(RS 273-073)<br />
Red Lead ----->R1>--->----------------->Output Jack Tip<br />
|<br />
|<br />
>C1>-->H1>-->R2>-->Output Jack Ground<br />
<br />
R2 = 50k ohm audio taper potentiometer (linear will do)<br />
<br />
The pot has 3 terminals, terminal 1 connects to<br />
H1 and terminals 2 and 3 go to ground.<br />
<br />
This control will travel from full filter to<br />
complete elimination of the filter fom the<br />
circuit.<br />
<br />
5. If you have an assortment of caps, you can<br />
change the notch to "flavor" the instrument by<br />
experimenting with various values. You can also<br />
try other inductor/cap combinations and even<br />
change the resistors value BUT... the source<br />
(driving) impedance should be LOWER than the<br />
impedance of the filter. Also, the output of the<br />
filter should feed an impedance (amplifier) much<br />
HIGHER than the filter impedance.<br />
<br />
<br />
All and all, I have found this a very good<br />
sounding transducer especially at the price. If<br />
you put this on a nice acoustic guitar, the<br />
end-pin jack would cost you more than the<br />
transducer system.<br />
<br />
Well, I hope this info will prove useful to you<br />
and I'll keep an eye on your page, which has<br />
provided me with alot of ideas on my own<br />
projects.<br />
<br />
Thanks Clark Rowden"<br />
<br />
<br />
<br/>
<br/>
<cite>Don Thompson said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment256224"><div>Yep, My guess is a much larger value for the tone pot. On the order of 1Meg or more. Piezos simply do not have the same electrical values as a magnetic pickup so what works for one won't work for the other. Don<br/> <br/>
<cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A256201&xg_source=msg_com_forum#2592684Comment256201"><div>I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br/>Id be interested as to what you find in there - could be a leprechaun!</div>
</blockquote>
</div>
</blockquote> Personally, I gave up on pass…tag:www.cigarboxnation.com,2010-11-03:2592684:Comment:3465162010-11-03T05:58:11.761ZGlenn Reitherhttps://www.cigarboxnation.com/profile/GlennReither
Personally, I gave up on passive tone control and wanted to drive amps etc properly so I build Tillman preamp circuits on perfboard now and run the output through tone and vol control. I would guess the total cost of parts would be under $2.BUT if you do want to try passive tone control, I came across that Charlie Hall info a while ago and asked Charlie what values to try and he sent me this:<br />
"Piezo pickups need a very high impedance. Usually something like 3 to 5 megohms. Unfortunately typical…
Personally, I gave up on passive tone control and wanted to drive amps etc properly so I build Tillman preamp circuits on perfboard now and run the output through tone and vol control. I would guess the total cost of parts would be under $2.BUT if you do want to try passive tone control, I came across that Charlie Hall info a while ago and asked Charlie what values to try and he sent me this:<br />
"Piezo pickups need a very high impedance. Usually something like 3 to 5 megohms. Unfortunately typical tone and volume pots do not come in this range so ideally you do need a preamp before any controls.<br />
A standard electric guitar pickup is affected by input resistance and capacitance. Lowering the resistance will reduce the amount of the pickup's resonant peak. Increasing capacitance will change the resonant frequency to a lower frequency.<br />
"A piezo pickup reacts completely differently. Lowering the input resistance will reduce bass. Increasing capacitance will reduce volume. This is why when adding the usual type of guitar tone control to a piezo pickup it acts as a volume control instead of a tone control. Adding a suitable resistor in series with the piezo pickup will help to convert the piezo signal so that a guitar tone control will work more like expected. I would start with a resistor of maybe 100K between the pickup and the tone control. Wattage rating doesn't matter so you can use a resistor type that is physically very small. The tone control should be a fairly high value, maybe 1 meg log. The value of the pot won't affect the bass because the capacitor will stop bass from being lost. The tone capacitor can probably be one of the standard values used in electric guitars such as 0.022uF, 0.047uF or 0.1uF. If the 100K resistor value works then it should do. If it works but not effectively, try a larger value resistor like 220K or 470K until it does. I would then connect that point to a volume pot of 1 meg log or even 2 meg log if you can get one. The pickup will see a total resistance that is the value of the resistor and the volume pot added together. This total will be reduced because of the input impedance of whatever the instrument is connected to. The larger the pot values, the less signal you will lose. The downside is that with a larger value volume pot, you will lose more highs from the signal when the volume pot setting is reduced but you will not lose quite so much bass. Adding a bypass capacitor to the volume pot might help to retain lost highs when the volume setting is reduced. The larger value that your added resistor is, the more highs you could lose with the volume control backed off. I would try something like 100pf as a bypass capacitor if you think you will need one. The value chosen will depend on the capacitance (length and type) of cable you use from the instrument. I would choose the shortest cable that you can comfortably work with. For an external preamp, you can still use a preamp that has a high impedance designed for piezo pickups and you may find one that has extra tone controls to fine tune the sound. Or you can use an FET design with an input resistor to earth or ground of 3.3 or 4.7 megohms. It won't work as well as having the preamp in the instrument and the controls in the usual place within the preamp design itself, but I think it is the only way to do what you want. By juggling with values, you will be able to figure out compromise settings that work as best possible for your instruments."<br />
<br/>
<br/>
<cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment253841"><div>Hi David,<br/> Yep, Iv been trying this all damn day!!<br/>
Mine is with tone and vol though - the vol works great, the tone - not at all!<br/>
<br/>
I found the same text, but it doesnt help with values, so I experimented a little.<br/>
I tried lots of different resistors, then tried a load in series - nothing.<br/>
I then tried a .47k cap between the vol and the tone (as well as the standard tone cap) to reduce the signal - still nothing audibley different.<br/>
<br/>
Iv found a wiring diagram for tone only on a piezo if you want it - I havnt tried it yet but it looks like it should work.<br/>
<br/>
Next step for me is replace the standard .47k cap with a whole variety of others, see if it works any better.<br/>
Il keep you posted<br/>
B</div>
</blockquote> David, Thanks for sharing. Do…tag:www.cigarboxnation.com,2010-07-16:2592684:Comment:2639282010-07-16T11:54:32.962ZDon Thompsonhttps://www.cigarboxnation.com/profile/DonThompson
David, Thanks for sharing. Don<br />
<cite>David Lloyd said:</cite><br />
<blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment262996"><div>I received the passive preamp today and was surprised to find it works well, the tone control is effective and it gives a good quality sound. It cost $3.99 plus $4.99 postage to UK off ebay.
<br></br>Here are a few pictures
…<br></br>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305653607?profile=RESIZE_1024x1024" width="721"></img></p>
</div>
</blockquote>
David, Thanks for sharing. Don <br />
<cite>David Lloyd said:</cite><br />
<blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment262996">
<div>
I received the passive preamp today and was surprised to find it works well, the tone control is effective and it gives a good quality sound. It cost $3.99 plus $4.99 postage to UK off ebay.<br />
<br>Here are a few pictures
<br>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305653607?profile=RESIZE_1024x1024" width="721"></p>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305654777?profile=RESIZE_1024x1024" width="721"></p>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305655808?profile=RESIZE_1024x1024" width="721"></p>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305656374?profile=RESIZE_1024x1024" width="721"></p>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305657410?profile=RESIZE_1024x1024" width="721"></p>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305658652?profile=RESIZE_1024x1024" width="721"></p>
<br>I think the schematic is something like the above - I have yet to work out how the pots work in this schematic (hidden on otherside of PCB and not sure if I can get to them.
<br>
<br>The resistor measures 22K on my multimeter.
</div>
</blockquote> I received the passive preamp…tag:www.cigarboxnation.com,2010-07-14:2592684:Comment:2629962010-07-14T17:51:15.775ZDavid L.https://www.cigarboxnation.com/profile/DavidLloyd
I received the passive preamp today and was surprised to find it works well, the tone control is effective and it gives a good quality sound. It cost $3.99 plus $4.99 postage to UK off ebay. Here are a few pictures<br />
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305653607?profile=RESIZE_1024x1024" width="721"></img></p>
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305654777?profile=RESIZE_1024x1024" width="721"></img></p>
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305655808?profile=RESIZE_1024x1024" width="721"></img></p>
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305656374?profile=RESIZE_1024x1024" width="721"></img></p>
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305657410?profile=RESIZE_1024x1024" width="721"></img></p>
<p style="text-align: left;"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305658652?profile=RESIZE_1024x1024" width="721"></img></p>
I think the…
I received the passive preamp today and was surprised to find it works well, the tone control is effective and it gives a good quality sound. It cost $3.99 plus $4.99 postage to UK off ebay. Here are a few pictures <br />
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305653607?profile=RESIZE_1024x1024" alt="" width="721"></p>
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305654777?profile=RESIZE_1024x1024" alt="" width="721"></p>
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305655808?profile=RESIZE_1024x1024" alt="" width="721"></p>
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305656374?profile=RESIZE_1024x1024" alt="" width="721"></p>
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305657410?profile=RESIZE_1024x1024" alt="" width="721"></p>
<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/305658652?profile=RESIZE_1024x1024" alt="" width="721"></p> I think the schematic is something like the above - I have yet to work out how the pots work in this schematic (hidden on otherside of PCB and not sure if I can get to them. The resistor measures 22K on my multimeter. Yep, My guess is a much large…tag:www.cigarboxnation.com,2010-07-03:2592684:Comment:2562242010-07-03T21:31:15.698ZDon Thompsonhttps://www.cigarboxnation.com/profile/DonThompson
Yep, My guess is a much larger value for the tone pot. On the order of 1Meg or more. Piezos simply do not have the same electrical values as a magnetic pickup so what works for one won't work for the other. Don<br />
<br />
<cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A256201&xg_source=msg_com_forum#2592684Comment256201"><div>I suspect its just a case of getting the…</div>
</blockquote>
Yep, My guess is a much larger value for the tone pot. On the order of 1Meg or more. Piezos simply do not have the same electrical values as a magnetic pickup so what works for one won't work for the other. Don<br />
<br />
<cite>Roosterman said:</cite><blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&commentId=2592684%3AComment%3A256201&xg_source=msg_com_forum#2592684Comment256201"><div>I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br/>Id be interested as to what you find in there - could be a leprechaun!</div>
</blockquote> I suspect its just a case of…tag:www.cigarboxnation.com,2010-07-03:2592684:Comment:2562012010-07-03T20:42:08.445ZRoostermanhttps://www.cigarboxnation.com/profile/RandyRoosterGuitars
I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br />
Id be interested as to what you find in there - could be a leprechaun!
I suspect its just a case of getting the right value parts, but calculating such things is black magic to me.<br />
Id be interested as to what you find in there - could be a leprechaun! Hi,
Thanks for the replies ge…tag:www.cigarboxnation.com,2010-07-03:2592684:Comment:2561562010-07-03T18:49:26.052ZDavid L.https://www.cigarboxnation.com/profile/DavidLloyd
Hi,<br />
Thanks for the replies gentlemen. After another hour spent playing around with capacitors and resistors (zero result) and drawing a blank on google I have bought one of the "passive preamps" off ebay…
Hi,<br />
Thanks for the replies gentlemen. After another hour spent playing around with capacitors and resistors (zero result) and drawing a blank on google I have bought one of the "passive preamps" off ebay<br />
<a href="http://cgi.ebay.co.uk/Acoustic-Guitar-Piezo-Pickup-Passive-Preamp-System-/150462528037?cmd=ViewItem&pt=Guitar_Accessories&hash=item230843fa25" target="_blank">http://cgi.ebay.co.uk/Acoustic-Guitar-Piezo-Pickup-Passive-Preamp-System-/150462528037?cmd=ViewItem&pt=Guitar_Accessories&hash=item230843fa25</a><br />
Once it arrives from china (if it actually works) I'll take the back off it and see what magical components thet have used. http://www.cyberferal.com/Unc…tag:www.cigarboxnation.com,2010-07-02:2592684:Comment:2556622010-07-02T20:26:40.952ZDon Thompsonhttps://www.cigarboxnation.com/profile/DonThompson
<a href="http://www.cyberferal.com/UncleBob/images/TwoPickupWirogram.gif" target="_blank">http://www.cyberferal.com/UncleBob/images/TwoPickupWirogram.gif</a> Another diagram which never worked for me and I built it exactly like it. Don<br />
<cite>Roosterman said:</cite><br />
<blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment255576"><div>This is what i was trying - a chap on the guitar nuts 2 site came up with it,…</div>
</blockquote>
<a href="http://www.cyberferal.com/UncleBob/images/TwoPickupWirogram.gif" target="_blank">http://www.cyberferal.com/UncleBob/images/TwoPickupWirogram.gif</a> Another diagram which never worked for me and I built it exactly like it. Don <br />
<cite>Roosterman said:</cite><br />
<blockquote cite="http://www.cigarboxnation.com/forum/topics/passive-tone-control-for-a?groupUrl=cbgwiringelectronics&#2592684Comment255576">
<div>
This is what i was trying - a chap on the guitar nuts 2 site came up with it, though I cant get it to work. I believe the cap and resistor values are very specific to the size of the piezo though, so this could be the problem.<br />
<br>
<br>I tried various resistors but still cant get any audible change in tone, so Im going plan B instead...
<br>
<br>Id love to hear if you get it working though - my knowledge is limited and it could be easy if you know a little!
<br>
<br>
<p style="TEXT-ALIGN: left"><img alt="" src="http://storage.ning.com/topology/rest/1.0/file/get/305658656?profile=original"></p>
</div>
</blockquote>