Piezo disc transducer spec question - Cigar Box Nation2024-03-29T09:17:59Zhttps://www.cigarboxnation.com/forum/topics/piezo-disc-transducer-spec-question?commentId=2592684%3AComment%3A2964892&xg_source=activity&feed=yes&xn_auth=noC.B.Gitty has 2 for 20bucks o…tag:www.cigarboxnation.com,2017-10-28:2592684:Comment:29702582017-10-28T20:26:56.256ZPaul Craighttps://www.cigarboxnation.com/profile/PaulCraig
<p>C.B.Gitty has 2 for 20bucks or less that work well with rod piezos. Don't know how well they work with disc piezos or the input impedance, but I'm sure they'll handle it just fine.</p>
<p>C.B.Gitty has 2 for 20bucks or less that work well with rod piezos. Don't know how well they work with disc piezos or the input impedance, but I'm sure they'll handle it just fine.</p> A preamp is an excellent idea…tag:www.cigarboxnation.com,2017-10-26:2592684:Comment:29693982017-10-26T22:02:43.454ZGwil Colmanhttps://www.cigarboxnation.com/profile/GwilColman
<p>A preamp is an excellent idea as long as it has a high input impedance - at least 1 Megohm and preferably higher. Can't help noticing that neither of these ebay listings quote an input impedance. Have they been tried in a CBG? They might be OK but personally I'd go for a preamp specifically designed for buffering a piezo pickup. </p>
<p>A preamp is an excellent idea as long as it has a high input impedance - at least 1 Megohm and preferably higher. Can't help noticing that neither of these ebay listings quote an input impedance. Have they been tried in a CBG? They might be OK but personally I'd go for a preamp specifically designed for buffering a piezo pickup. </p> A preamp is cheap, and easy t…tag:www.cigarboxnation.com,2017-10-25:2592684:Comment:29681492017-10-25T13:24:32.547ZKirkhttps://www.cigarboxnation.com/profile/Kirk114
<p>A preamp is cheap, and easy to install, and can really bring down the harshness of a piezo (and John Nickel would be happy, because you don't need giant blobs of hot glue). …</p>
<p></p>
<p>A preamp is cheap, and easy to install, and can really bring down the harshness of a piezo (and John Nickel would be happy, because you don't need giant blobs of hot glue). </p>
<p><a href="https://www.ebay.com/itm/3V-6V-TDA1308-Headphone-Amplifier-Board-AMP-Module-Preamplifier-For-arduino-DIY/371699396919?epid=1480002055&hash=item568b02b137:g:6swAAOSwo4pYiZFU" target="_blank">https://www.ebay.com/itm/3V-6V-TDA1308-Headphone-Amplifier-Board-AMP-Module-Preamplifier-For-arduino-DIY/371699396919?epid=1480002055&hash=item568b02b137:g:6swAAOSwo4pYiZFU</a></p>
<p></p>
<p><a href="https://www.ebay.com/itm/NE5532-OP-AMP-Audio-HIFI-Preamplifier-Dual-Preamp-Board-for-Bluetooth-Pre-amp/262952631771?hash=item3d3932bddb:g:LQYAAOSw5UZY~yEy" target="_blank">https://www.ebay.com/itm/NE5532-OP-AMP-Audio-HIFI-Preamplifier-Dual-Preamp-Board-for-Bluetooth-Pre-amp/262952631771?hash=item3d3932bddb:g:LQYAAOSw5UZY~yEy</a></p>
<p></p>
<p></p>
<p></p>
<p></p>
<p></p> That's basically a tone cap p…tag:www.cigarboxnation.com,2017-10-25:2592684:Comment:29681372017-10-25T07:56:23.755ZPaul Craighttps://www.cigarboxnation.com/profile/PaulCraig
<p>That's basically a tone cap passing highs to ground.</p>
<p>Haven't tried that without a volume pot. I'd rather have a volume pot so I can keep my amp settings at the sweet spot and also don't have to go back and forth to the amp that way. With a 500k volume pot, a .047 cap would probably work fine.</p>
<p>That's basically a tone cap passing highs to ground.</p>
<p>Haven't tried that without a volume pot. I'd rather have a volume pot so I can keep my amp settings at the sweet spot and also don't have to go back and forth to the amp that way. With a 500k volume pot, a .047 cap would probably work fine.</p> The easiest way to control an…tag:www.cigarboxnation.com,2017-10-24:2592684:Comment:29669832017-10-24T20:00:33.796ZRTZGUITARShttps://www.cigarboxnation.com/profile/RTZGUITARS
<p>The easiest way to control any piezo is to put a cap. acrossed the pickup leads. Simple no pots not perfect but cheap easy way to control it. try Gittys .068 caps. </p>
<p>The easiest way to control any piezo is to put a cap. acrossed the pickup leads. Simple no pots not perfect but cheap easy way to control it. try Gittys .068 caps. </p> High impedance transducers li…tag:www.cigarboxnation.com,2017-10-23:2592684:Comment:29663312017-10-23T22:31:08.114ZJoseph J. Rogowskihttps://www.cigarboxnation.com/profile/JosephJRogowski
High impedance transducers like piezo devices have a very high impedance and will get loaded down by using volume controls in the 500K ohm to 1 Meg ohm range. This passive volume control is also in parallel with the input impedance of a typical guitar amp which is about 1 Meg ohms. If you combine these parallel loads it Looks like a 500 K ohm load to the piezo device.<br></br>
<br></br>
Here is an experiment to try. Obtain a Scatten Design mini pre which has a 10 Meg ohm input impedance. Connect your…
High impedance transducers like piezo devices have a very high impedance and will get loaded down by using volume controls in the 500K ohm to 1 Meg ohm range. This passive volume control is also in parallel with the input impedance of a typical guitar amp which is about 1 Meg ohms. If you combine these parallel loads it Looks like a 500 K ohm load to the piezo device.<br/>
<br/>
Here is an experiment to try. Obtain a Scatten Design mini pre which has a 10 Meg ohm input impedance. Connect your piezo device directly to this preamp/buffer and plug your long guitar cable into the output of the mini pre and you will isolate the piezo device from the amp input loading and the effect of a 10 foot guitar cable having about 350 pico faraday (pf) of capacitance whose reactants (like resistance but at a specified AC frequency). The 350 pf cable capacitance looks like this ar various frequencies. 100 HZ 4,457,285 ohms, 1000 HZ 454,728 ohms, 5000 HZ 90,946 ohms and at 10000 HZ 45,473 ohms. So, as you can see higher frequencies are subject to more high frequency load but the Schatten mini pre isolates the piezo device from that loading because the output impedance of the mini pre is 3,500 ohms and even at the highest frequency the cable capacitance is over 10 Times higher than the output impedance and it looks like a bridging load on the preamp. Look up these words on the web “bridging impedance” and “matching impedance”. This will give you an appreciation for how cable types, lengths and source impedance values all interact to affect the sound you hear.<br/>
<br/>
I hope this helps?<br/>
<br/>
Joseph J. Rogowski I've been wondering about usi…tag:www.cigarboxnation.com,2017-10-23:2592684:Comment:29661672017-10-23T22:02:58.605ZPaul Craighttps://www.cigarboxnation.com/profile/PaulCraig
<p>I've been wondering about using a high pass filter on one of these round piezo's myself. In a guitar situation, a .047 cap inline with the neck pickup's signal wire to the switch/volume pot can reduce the muddy tone of a neck pickup due to high bass. So I was thinking that a .022 or lower value cap would tame the high shrillness associated with the round piezo. </p>
<p>I've been wondering about using a high pass filter on one of these round piezo's myself. In a guitar situation, a .047 cap inline with the neck pickup's signal wire to the switch/volume pot can reduce the muddy tone of a neck pickup due to high bass. So I was thinking that a .022 or lower value cap would tame the high shrillness associated with the round piezo. </p> I am just now learning the ja…tag:www.cigarboxnation.com,2017-10-23:2592684:Comment:29663942017-10-23T19:23:56.704ZBryan Pieperhttps://www.cigarboxnation.com/profile/BryanPieper
I am just now learning the jargon, so I’m not sure what you mean by the phrase, “If you load the piezo with from 3 meg ohms to 10 meg ohms. . .” I have read about piezos being high impedance, and that therefore you may need a preamp for them to work with a guitar amp, but I’m not sure if that is what the above line means exactly. Can you elaborate on that for me?
I am just now learning the jargon, so I’m not sure what you mean by the phrase, “If you load the piezo with from 3 meg ohms to 10 meg ohms. . .” I have read about piezos being high impedance, and that therefore you may need a preamp for them to work with a guitar amp, but I’m not sure if that is what the above line means exactly. Can you elaborate on that for me? If you load the piezo with fr…tag:www.cigarboxnation.com,2017-10-23:2592684:Comment:29660762017-10-23T18:29:02.819ZJoseph J. Rogowskihttps://www.cigarboxnation.com/profile/JosephJRogowski
If you load the piezo with from 3 meg ohms to 10 meg ohms you will boost the lower end of the response. Piezo devices are capacitive driven and have a higher impedance to lower frequencies just the opposite of wire wound inductive guitar pickups. Just connect your piezo device to a small amp with a 1 foot cable and listen to the difference compared to using a typical 10 foot cable. Eliminating cable capacitance and raising the impedance very near the piezo device is the simplist…
If you load the piezo with from 3 meg ohms to 10 meg ohms you will boost the lower end of the response. Piezo devices are capacitive driven and have a higher impedance to lower frequencies just the opposite of wire wound inductive guitar pickups. Just connect your piezo device to a small amp with a 1 foot cable and listen to the difference compared to using a typical 10 foot cable. Eliminating cable capacitance and raising the impedance very near the piezo device is the simplist solution.<br />
<br />
Joseph J. Rogowski Without getting into all the…tag:www.cigarboxnation.com,2017-10-23:2592684:Comment:29660712017-10-23T18:17:23.073ZBryan Pieperhttps://www.cigarboxnation.com/profile/BryanPieper
Without getting into all the details about impedance, high pass filtering, and the impact of adding a preamp, I think I’ve figured out the simplified general answer from continued reading. Tell me if I’m close: A piezo disc with a 1.0 kHz resonant frequency peak is going to have an easier time transmitting (i.e., will transmit more of) the frequencies closer to 1 kHz (for guitar, that’s midrange), with the strength of the frequencies dropping off as they move farther away from 1 kHz. It will…
Without getting into all the details about impedance, high pass filtering, and the impact of adding a preamp, I think I’ve figured out the simplified general answer from continued reading. Tell me if I’m close: A piezo disc with a 1.0 kHz resonant frequency peak is going to have an easier time transmitting (i.e., will transmit more of) the frequencies closer to 1 kHz (for guitar, that’s midrange), with the strength of the frequencies dropping off as they move farther away from 1 kHz. It will transmit other frequencies, just not quite as well as frequencies near it’s resonant frequency peak. A piezo disc with a resonant frequency peak of 4.0 kHz is going to be best at transmitting frequencies near 4 kHz (upper midrange or presence), again, with it dropping off as the frequencies move farther away from 4 kHz. Similar story with the 9.0 kHz piezo disc, which will have the easiest time transmitting frequencies in the brilliance/harmonics/air range, while still transmitting others. Note that none of the discs I’ve seen have their strongest point (resonant frequency peak) in the lows or bass range, so while they will transmit low frequencies, they won’t do so quite as well as they transmit the frequencies near their respective resonant peaks. Maybe this is why piezo disc pickups often act as a high-pass filter and/or have a “tinny” or higher, thinner sound than the acoustic instrument itself does. Am I at least getting warm there?<br />
<br />
I know what I’m going to do. I’m going to buy a disc from each extreme end and one from the middle, then test them each separately on the same instrument to see what difference, if any, I can hear. I’m too curious not to do that kind of experiment. Assuming my theory is borne out by the experiment, I may wire three disks (one with lower resonant peak, one middle, one high) in parallel to the same jack, mounting each disc inside the instrument where those holographic interferometry images say the instrument vibrates most at each respective disc’s “favorite” frequencies. I wonder if that will provide a fuller sound profile that more closely approximates the acoustic sound being produced by the instrument? If that seems to work and I’m still feeling curious, I might even add a rod piezo under the saddle, wire it in parallel with the three discs, and see how that affects the combined result.<br />
<br />
I realize a simpler solution might be to just add a buffer or preamp to one piezo transducer and improve the sound that way, but it will be fun to see what kind of result this gets.