<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:14pt"><div><span>Piezo mics should go through a very high impedance buffer stage. When I say high impedance, I'm talking 10 megohms minimum. 1 Meg is too low, it basically will act as a high pass filter and your piezo will sound tinny. This page explains all and has a cute 1 stage FET buffer. I have built about 10 of these buffers and they work perfectly, sound great and do not clip: </span></div><div><span><br></span></div><div><span>http://www.muzique.com/news/piezo-pickups/</span></div><div><br></div><div>I bought generic 1 stage buffer PCBs from MusikDing and they keep the buffer circuitry tidy. The circuits, batteries and connectors were housed in guitar pedal/DI style boxes<br></div><div><span><br></span></div><div><span>If you want to tame piezo transients, you can use a small coil. This is what Roland do in those drums pads units -
they stick a coil in series with the piezo to smooth out the peaks (a bit like a tiny compressor... ish) </span></div><div><span><br></span></div><div><span>For high-quality sound, don't use piezo - MEAS film contact mics are better. They are more expensive, but some outfit in Canada sent me a bunch for not much money so not too bad. They are finicky to solder - we're talkin' low wattage irons, lead solder (sorry ROHS) and heatsink clips. </span></div><div><span><br></span></div><div><span>You can also use an active DI box to interface your piezos - one that has a high impedence input. Normal Line level inputs are not high enough impedance for piezos, by the way. I've used BSS DI's on piezos and they sound great. I've also experimented with those cheapo Behringer active DIs - and they sound very good on piezos too. They come in a phantom/battery-powered stereo DI version for about 20 euro - 2 piezos to 2 channels on your desk per DI.
</span></div><div> </div><div>Rich Duckworth<br>Lecturer in Music Technology<br>Department of Music<br>House 5 <br>Trinity College <br>Dublin 2<br>Ireland<br><br></div><div>Tel 353 1 896 1500</div><br><br><div>It's the most devastating moment in a young mans life, when he quite reasonably says to himself, "I shall never play The Dane!"<br> <div style="font-size: 14pt; font-family: arial, helvetica, sans-serif; "> <div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "> <div dir="ltr"> <font size="2" face="Arial"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> "pd-list-request@iem.at" <pd-list-request@iem.at><br> <b><span style="font-weight: bold;">To:</span></b> pd-list@iem.at <br> <b><span style="font-weight: bold;">Sent:</span></b> Saturday, 21 April 2012, 0:17<br> <b><span style="font-weight: bold;">Subject:</span></b> Pd-list Digest, Vol 85, Issue 61<br> </font> </div> <br>Send
Pd-list mailing list submissions to<br> <a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br> <a href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br>or, via email, send a message with subject or body 'help' to<br> <a ymailto="mailto:pd-list-request@iem.at" href="mailto:pd-list-request@iem.at">pd-list-request@iem.at</a><br><br>You can reach the person managing the list at<br> <a ymailto="mailto:pd-list-owner@iem.at" href="mailto:pd-list-owner@iem.at">pd-list-owner@iem.at</a><br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of Pd-list digest..."<br><br><br>Today's Topics:<br><br> 1. Re: PhD Defense / Acknowledgement to the Pd-list<br> (Hans-Christoph
Steiner)<br> 2. Re: PhD Defense / Acknowledgement to the Pd-list (Jim Hickcox)<br> 3. (OT) safely connect piezo transducer to soundcard as<br> microphone (Matteo Sisti Sette)<br> 4. Re: (OT) safely connect piezo transducer to soundcard as<br> microphone (Martin Peach)<br> 5. Re: (OT) safely connect piezo transducer to soundcard as<br> microphone (katja)<br> 6. Re: Help with Jack and PD (Michal Seta)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Fri, 20 Apr 2012 09:55:55 -0400<br>From: Hans-Christoph Steiner <<a ymailto="mailto:hans@at.or.at" href="mailto:hans@at.or.at">hans@at.or.at</a>><br>Subject: Re: [PD] PhD Defense / Acknowledgement to the Pd-list<br>To: Alexandre Torres Porres <<a ymailto="mailto:porres@gmail.com" href="mailto:porres@gmail.com">porres@gmail.com</a>><br>Cc:
pd-lista puredata <<a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a>><br>Message-ID: <<a ymailto="mailto:D7F486B1-8D83-405D-A68E-7C6A5C023646@at.or.at" href="mailto:D7F486B1-8D83-405D-A68E-7C6A5C023646@at.or.at">D7F486B1-8D83-405D-A68E-7C6A5C023646@at.or.at</a>><br>Content-Type: text/plain; charset="us-ascii"<br><br><br>Congratulations on finishing it! Hope the defense went well.<br><br>.hc<br><br>On Apr 10, 2012, at 12:49 AM, Alexandre Torres Porres wrote:<br><br>> Hi Folks<br>> <br>> I defend my PhD thesis this friday here in Brazil. I'd like to share it with you because this list has always been very helpful, I actually made a remark about it in my acknowledgements. And I also put a special remark to all who were here for PdCon09, that was a great experience for me! :)<br>> <br>> My draft text, submitted to the board, is at the following link; <a
href="https://docs.google.com/open?id=0B3AoiT0xk8fnZThjOWQ3YzUtOGUzYS00NGVjLTkwN2QtZjE1MmExZDY0Y2Ey" target="_blank">https://docs.google.com/open?id=0B3AoiT0xk8fnZThjOWQ3YzUtOGUzYS00NGVjLTkwN2QtZjE1MmExZDY0Y2Ey</a> I shall update it though after friday according to the feedback. Then I'll release an official one later one. Wish me luck.<br>> <br>> I know most of you can't read portuguese, sorry.<br>> <br>> I've used lots of Pd in the research as you might wonder, and there several figures on the text all made from patches. As soon as I get to clean them all along with the text, I'll spread it out over here.<br>> <br>> Thanks a lot people<br>> <br>> 'til next time<br>> Alex<br>> <br>> _______________________________________________<br>> <a ymailto="mailto:Pd-list@iem.at" href="mailto:Pd-list@iem.at">Pd-list@iem.at</a> mailing list<br>> UNSUBSCRIBE and account-management -> <a
href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br><br><br><br>----------------------------------------------------------------------------<br><br>"[W]e have invented the technology to eliminate scarcity, but we are deliberately throwing it away to benefit those who profit from scarcity." -John Gilmore<br><br><br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <<a href="http://lists.puredata.info/pipermail/pd-list/attachments/20120420/c3caaea8/attachment-0001.htm" target="_blank">http://lists.puredata.info/pipermail/pd-list/attachments/20120420/c3caaea8/attachment-0001.htm</a>><br><br>------------------------------<br><br>Message: 2<br>Date: Fri, 20 Apr 2012 12:15:30 -0400<br>From: Jim Hickcox <<a ymailto="mailto:tango.mceffrie@gmail.com"
href="mailto:tango.mceffrie@gmail.com">tango.mceffrie@gmail.com</a>><br>Subject: Re: [PD] PhD Defense / Acknowledgement to the Pd-list<br>To: Hans-Christoph Steiner <<a ymailto="mailto:hans@at.or.at" href="mailto:hans@at.or.at">hans@at.or.at</a>><br>Cc: pd-lista puredata <<a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a>>, Alexandre Torres Porres<br> <<a ymailto="mailto:porres@gmail.com" href="mailto:porres@gmail.com">porres@gmail.com</a>><br>Message-ID:<br> <CACjk_r1bMCR_1vUcv=FUsPO8+Fx5OB0QPa6iPFGp+<a ymailto="mailto:0aHLpBYCw@mail.gmail.com" href="mailto:0aHLpBYCw@mail.gmail.com">0aHLpBYCw@mail.gmail.com</a>><br>Content-Type: text/plain; charset=ISO-8859-1<br><br>Good luck with the defense!<br><br>On Fri, Apr 20, 2012 at 9:55 AM, Hans-Christoph Steiner <<a ymailto="mailto:hans@at.or.at" href="mailto:hans@at.or.at">hans@at.or.at</a>>
wrote:<br>><br>> Congratulations on finishing it! ?Hope the defense went well.<br>><br>> .hc<br>><br>> On Apr 10, 2012, at 12:49 AM, Alexandre Torres Porres wrote:<br>><br>> Hi Folks<br>><br>> I defend my PhD thesis this friday here in Brazil. I'd like to share it with<br>> you because this list has always been very helpful, I actually made a remark<br>> about it in my acknowledgements. And I also put a special remark to all who<br>> were here for PdCon09, that was a great experience for me! :)<br>><br>> My draft text, submitted to the board, is at the following<br>> link;?<a href="https://docs.google.com/open?id=0B3AoiT0xk8fnZThjOWQ3YzUtOGUzYS00NGVjLTkwN2QtZjE1MmExZDY0Y2Ey?I" target="_blank">https://docs.google.com/open?id=0B3AoiT0xk8fnZThjOWQ3YzUtOGUzYS00NGVjLTkwN2QtZjE1MmExZDY0Y2Ey?I</a><br>> shall update it though after friday according to the feedback. Then I'll<br>> release an official one
later one. Wish me luck.<br>><br>> I know most of you can't read portuguese, sorry.<br>><br>> I've used lots of Pd in the research as you might wonder, and there several<br>> figures on the text all made from patches. As soon as I get to clean them<br>> all along with the text, I'll spread it out over here.<br>><br>> Thanks a lot people<br>><br>> 'til next time<br>> Alex<br>><br>> _______________________________________________<br>> <a ymailto="mailto:Pd-list@iem.at" href="mailto:Pd-list@iem.at">Pd-list@iem.at</a> mailing list<br>> UNSUBSCRIBE and account-management -><br>> <a href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br>><br>><br>><br>><br>> ----------------------------------------------------------------------------<br>><br>> "[W]e have invented the technology to eliminate scarcity, but we are<br>>
deliberately throwing it away to benefit those who profit from scarcity."<br>> ? ??-John Gilmore<br>><br>><br>><br>> _______________________________________________<br>> <a ymailto="mailto:Pd-list@iem.at" href="mailto:Pd-list@iem.at">Pd-list@iem.at</a> mailing list<br>> UNSUBSCRIBE and account-management -><br>> <a href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br>><br><br><br><br>------------------------------<br><br>Message: 3<br>Date: Sat, 21 Apr 2012 00:12:54 +0200<br>From: Matteo Sisti Sette <<a ymailto="mailto:matteosistisette@gmail.com" href="mailto:matteosistisette@gmail.com">matteosistisette@gmail.com</a>><br>Subject: [PD] (OT) safely connect piezo transducer to soundcard as<br> microphone<br>To: PD-List <<a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a>><br>Message-ID: <<a
ymailto="mailto:4F91DF66.6030708@gmail.com" href="mailto:4F91DF66.6030708@gmail.com">4F91DF66.6030708@gmail.com</a>><br>Content-Type: text/plain; charset=ISO-8859-1; format=flowed<br><br>Hi,<br><br>This is OT but I'm sure many of you have used piezo microphones sometimes.<br><br>I've often connected a piezo transducer to the microphone input of my <br>computer (and other computers) by simply soldering the two wires to the <br>T and S of a minijack plug, and it works just fine and my soundcard <br>hasn't suffered any damage (apparently at least).<br><br>However, I am concerned that a strong sound input (e.g. hitting the <br>piezo transducer with with fair strength) may actually generate a <br>voltage peak (thought only for a short time) capable of damaging the <br>soundcard, couldn't it?<br><br>Also, a friend of mine did the same with his Macbook and his headphones <br>output has stopped working (may be just a coincidence though).<br><br>Is there an
easy way to make it safer? I seem to remember I had read <br>somewhere (can't find it) about connecting a 1MOhm resistor in <br>parallel... woudl that do the trick?<br><br>thanks<br>m.<br><br><br><br>------------------------------<br><br>Message: 4<br>Date: Fri, 20 Apr 2012 18:38:53 -0400<br>From: Martin Peach <<a ymailto="mailto:martin.peach@sympatico.ca" href="mailto:martin.peach@sympatico.ca">martin.peach@sympatico.ca</a>><br>Subject: Re: [PD] (OT) safely connect piezo transducer to soundcard as<br> microphone<br>To: Matteo Sisti Sette <<a ymailto="mailto:matteosistisette@gmail.com" href="mailto:matteosistisette@gmail.com">matteosistisette@gmail.com</a>><br>Cc: PD-List <<a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a>><br>Message-ID: <<a ymailto="mailto:BLU0-SMTP11C079BB820A3B32FFB2B5ED220@phx.gbl"
href="mailto:BLU0-SMTP11C079BB820A3B32FFB2B5ED220@phx.gbl">BLU0-SMTP11C079BB820A3B32FFB2B5ED220@phx.gbl</a>><br>Content-Type: text/plain; charset="ISO-8859-1"; format=flowed<br><br>You could put a resistor in series to limit the current or a pair of <br>diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like <br>this would work:<br><br>IN---+------+-----OUT<br> | |<br> ^ v<br> | |<br>GND--+------+-----<br><br>Martin<br><br>On 2012-04-20 18:12, Matteo Sisti Sette wrote:<br>> Hi,<br>><br>> This is OT but I'm sure many of you have used piezo microphones sometimes.<br>><br>> I've often connected a piezo transducer to the microphone input of my<br>> computer (and other computers) by simply soldering the two wires to the<br>> T and S of a minijack plug, and it works just fine and my soundcard<br>>
hasn't suffered any damage (apparently at least).<br>><br>> However, I am concerned that a strong sound input (e.g. hitting the<br>> piezo transducer with with fair strength) may actually generate a<br>> voltage peak (thought only for a short time) capable of damaging the<br>> soundcard, couldn't it?<br>><br>> Also, a friend of mine did the same with his Macbook and his headphones<br>> output has stopped working (may be just a coincidence though).<br>><br>> Is there an easy way to make it safer? I seem to remember I had read<br>> somewhere (can't find it) about connecting a 1MOhm resistor in<br>> parallel... woudl that do the trick?<br>><br>> thanks<br>> m.<br>><br>> _______________________________________________<br>> <a ymailto="mailto:Pd-list@iem.at" href="mailto:Pd-list@iem.at">Pd-list@iem.at</a> mailing list<br>> UNSUBSCRIBE and account-management -><br>> <a
href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br>><br>><br><br><br><br><br>------------------------------<br><br>Message: 5<br>Date: Sat, 21 Apr 2012 00:42:42 +0200<br>From: katja <<a ymailto="mailto:katjavetter@gmail.com" href="mailto:katjavetter@gmail.com">katjavetter@gmail.com</a>><br>Subject: Re: [PD] (OT) safely connect piezo transducer to soundcard as<br> microphone<br>To: <a ymailto="mailto:pd-list@iem.at" href="mailto:pd-list@iem.at">pd-list@iem.at</a><br>Message-ID:<br> <<a ymailto="mailto:CAFY0eaq1g1TY3ffVRRaYYRsR4_mKRwi4RQTK9VVJuyiR1LhhUw@mail.gmail.com" href="mailto:CAFY0eaq1g1TY3ffVRRaYYRsR4_mKRwi4RQTK9VVJuyiR1LhhUw@mail.gmail.com">CAFY0eaq1g1TY3ffVRRaYYRsR4_mKRwi4RQTK9VVJuyiR1LhhUw@mail.gmail.com</a>><br>Content-Type: text/plain; charset=ISO-8859-1<br><br>Hi,<br><br>A piezo transducer often produces a signal level
somewhere inbetween<br>mic level and line level (it depends on size, and method of<br>excitation). Indeed it can be too loud when mic input is used.<br><br>Another point of concern is impedance, which influences the sound<br>character. If you mount a resistor (in series), the signal level is<br>reduced but the sound is altered as well. Mounting a capacitor (in<br>parallel or series) also works to reduce signal level and alter the<br>sound. Combinations of these (RC networks, effectively) are a great<br>way to tune the sound character to your liking, but it takes a lot of<br>experimentation. Also, the result may be different for each (mic)<br>preamp because input impedance is not fully standardized.<br><br><br>Katja<br><br><br><br>On Sat, Apr 21, 2012 at 12:12 AM, Matteo Sisti Sette<br><<a ymailto="mailto:matteosistisette@gmail.com" href="mailto:matteosistisette@gmail.com">matteosistisette@gmail.com</a>> wrote:<br>> Hi,<br>><br>> This is
OT but I'm sure many of you have used piezo microphones sometimes.<br>><br>> I've often connected a piezo transducer to the microphone input of my<br>> computer (and other computers) by simply soldering the two wires to the T<br>> and S of a minijack plug, and it works just fine and my soundcard hasn't<br>> suffered any damage (apparently at least).<br>><br>> However, I am concerned that a strong sound input (e.g. hitting the piezo<br>> transducer with with fair strength) may actually generate a voltage peak<br>> (thought only for a short time) capable of damaging the soundcard, couldn't<br>> it?<br>><br>> Also, a friend of mine did the same with his Macbook and his headphones<br>> output has stopped working (may be just a coincidence though).<br>><br>> Is there an easy way to make it safer? I seem to remember I had read<br>> somewhere (can't find it) about connecting a 1MOhm resistor in
parallel...<br>> woudl that do the trick?<br>><br>> thanks<br>> m.<br>><br>> _______________________________________________<br>> <a ymailto="mailto:Pd-list@iem.at" href="mailto:Pd-list@iem.at">Pd-list@iem.at</a> mailing list<br>> UNSUBSCRIBE and account-management -><br>> <a href="http://lists.puredata.info/listinfo/pd-list" target="_blank">http://lists.puredata.info/listinfo/pd-list</a><br><br><br><br>------------------------------<br><br>Message: 6<br>Date: Fri, 20 Apr 2012 19:16:37 -0400<br>From: Michal Seta <<a ymailto="mailto:mis@artengine.ca" href="mailto:mis@artengine.ca">mis@artengine.ca</a>><br>Subject: Re: [PD] Help with Jack and PD<br>To: Rishabh Natarajan <<a ymailto="mailto:rishabh.natarajan@gmail.com" href="mailto:rishabh.natarajan@gmail.com">rishabh.natarajan@gmail.com</a>><br>Cc: pd-list <<a ymailto="mailto:pd-list@iem.at"
href="mailto:pd-list@iem.at">pd-list@iem.at</a>><br>Message-ID:<br> <CABVh59=7KMxwa-ksQDD8GdNTapdRcHeU0icvWM8y8nXmNaAx+<a ymailto="mailto:Q@mail.gmail.com" href="mailto:Q@mail.gmail.com">Q@mail.gmail.com</a>><br>Content-Type: text/plain; charset="utf-8"<br><br>On Thu, Apr 19, 2012 at 9:49 AM, Rishabh Natarajan <<br><a ymailto="mailto:rishabh.natarajan@gmail.com" href="mailto:rishabh.natarajan@gmail.com">rishabh.natarajan@gmail.com</a>> wrote:<br><br>><br>> 1. When starting pd with jack and 16 channels, does this mean that all 16<br>> channels have to go in and out of Jack itself?<br>><br><br>no.<br><br><br>> 2. Do the number of input and output channels have to be the same (8 and 8<br>> in this case) or can they be different?<br>><br><br>they can be different.<br><br><br>> When I tried starting pd with 18 channels and then assigned 16 to Jack<br>> incoming and 2 to built-in output for outgoing,
terminal threw an error<br>> saying 'invalid number of channels'<br>><br><br>I am not sure on this one but I think that if Pd does not find as many<br>physical (or jack) inputs or outputs it will warn you. When you do provide<br>enough IO you can reconfigure Pd for the new values and it should work (if<br>you cross your fingers).<br><br>3. I want to have 8 channels from one adc~ and another 8 from the other.<br>> This means all 16 channels are meant for input. How then do I route output<br>> from pd to the speakers?<br>><br><br>you specify -audioindev 1,2 for example. You can specify -audiooutdev in<br>the same way and then you create the appropriate [dac~] objects. BTW, I<br>believe you can create aggregate devices on Mac (somewhere in the sound<br>preferences, I believe JackPilot manuals mentions that) to combine<br>different audio inputs and outputs. I vaguely recall doing something like<br>this in the past. Then you tell jack to use
your aggregate, this may<br>simplify your setup routine...<br><br><br>> 4. If I am only inputting 16 channels through Jack can I use the dac~<br>> object to output sound from pd to the speakers?<br>><br><br>if you run jack (and pd with -jack) then your [dac~] objects can be<br>connected to jack's outputs, i.e. Pd's inputs and outputs will appear in<br>JackPilot and you can route them any way you want to your system provided<br>I/O. Assuming that JackPilot uses the actual physical I/O, you should be<br>able to output sound from Pd to the speakers.<br><br>HTH,<br><br>./MiS<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <<a href="http://lists.puredata.info/pipermail/pd-list/attachments/20120420/f6e4a549/attachment.htm"
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