Home Made Pickup Success Nine Bucks!!

[WOOOOMPH]

Well Guys I Had to record into my DAT but, I could not opt to use the headphones to listen to the tracks in this particular case. I had to hear the Bass open to controll my Volume in each individual note played, heavy on the E and Light on the G etc... So Being broke from popping 700 in Strings this month I took A diagram posted on the Net somewhere on how to rig a Phantom Power supply to test drive different Electret Mic elements. Low and behold I modified the 5volt battery to 12 volt car key entry alarm battery, raised the resistance to compensate and doubled the Capacitance too, then I used a 3 dollar Pezo element from Radio Shack, Ripped the element out of the casing and shoved it under the Bass side bridge foot of my Bass . WAAAAMMM!!! Sounded like a million bucks compared to using my Sure Omni Mike. The Pezo was wafer thin under a 16th of an inch so the bridge height was not altered to bad, the Pezo is soft Brass so it bends to the contor of the Table and Bridge foot well. Of course I wont keep this setup it looks a tad ugly on my New Blond Bass, but it got me through the session at under ten bucks.
I posted the diagram and Pic of the bread board for the curious seekers out here. Later Dudes.
"I hightech Redneck with an Upright Bass, What next?"

[mje]

What's the point of the battery in using a piezo element? And what were you using for a preamp to match the impedance of the piezo element?

[WOOOOMPH]

The battery is needed for as a pezo does have characturistics of an Electret element in such as the ones found in a computer mic.

The battery/cap/resistor combo bring that out of the pezo. The mic goes into a Teac Dat mixdown board wich has seperate EQ's and Volume Pre and Final mix.
The dat mixer would be taking the place of the pre amp in this case. I am going to fool with a number of Elements I ordered on line, as I would like to make a pair of pickups that neatly fit "through" the holes of the Bridge Treble and Bass side and mix the two with a volume pot acting as a "Balance" knob, the tone controlls would be from an external preamp of ones chioce. Later...

[Robert]

So how did it sound? Any samples you could share?

[WOOOOMPH]

Originally Posted by Robert

So how did it sound? Any samples you could share?

At best I can email a *.mp3 or asf [you may choose] to you through an email address.
I don't like Realplayers spies and trojens and Quicktime in a Microsoft environment bites.

I haven’t figured out to host mp3 files on my earthlink web space, I think they dis-allow it, any suggestions on musician friendly web space host providers out there CHEAP of course.
cowboy6591NOSPAMERR@earthlink.net

Remove NOSPAMMERR from address.
Ya their robots even know how to grab NOSPAM from an address now, but misspelling it fowls that up :-)

Later :-)

[WOOOOMPH]

I sent you the demo Robert, It's not a "Hot Riffing" demo, it is structured to allow the "Note" to be heard with spaces between, as not to confuse. Very elementary playing, I wanted to project the tone and not a lot of notes, hell most you guys can play circles around me anyway
The file is about 800k so it's easy on the phone modem patrons out here. anyone wants an email of the demo just ask, remove the -at- from my address and replace it with an @ , Ya I hate Spam unless it’s in a can. Gawd those road trips in the back of a Silver Eagle Bus with Sony Martin back in the 80's I Ate plenty of it.

By the way this thing is ugly in the prototype stages, I wont get caught dead playing out with this, I love my blond bass as much as I love my blond [censored]. !! But it got me through a pinch.

cowboy6591-at-earthlink.net

[Robert]

I must say that I liked the sound. Lots of highs that maybe need to rolled off, but otherwise fully comparable to the $100 pickups out there. The question is how it sounds amplified, maybe those high will make the sound too bright?

[WOOOOMPH]

Originally Posted by Robert

I must say that I liked the sound. Lots of highs that maybe need to rolled off, but otherwise fully comparable to the $100 pickups out there. The question is how it sounds amplified, maybe those high will make the sound too bright?

I gave you a straight setting ACCEPT the last 10 seconds of Arco [plucking] That should have informed you how Mellow you can make it. Otherwise the Bow section was flat, Meaning I could have rolled the highs off but chose to roll of NOTHING so you could judge that for your self, One thing is for sure this is not a great discovery nor will it become the pro's favorite pickup, it is a tad nasaly, but to get the sound of my fingers squeeking along the silver windings of my gut strings is a big step over the run of the mill element type bridge foot pickups. Run that track through a stero with a graphic eq and see for your self you can tame them down, I didn't as not to misslead you. Later and thanks man. This stuff is fun especially when it is cheap !!! And works
I ran it through a lead amp Peavy Nashville 1000 open back and WOOOOMPH is the word with plenty of Resonance, just not very loud due to the open back amp.
Pardon my spelling but I got to run, a T-storm is comming and tornado warnings are out, last but not least the tornado alarms in town are sounding off, I have to shut down this network, LATER!!! Oh By the way I AM building my own Amp and speaker combo. Ramsey sells some nice digital switching power amps and I am handy with a Table saw, Drill press and wood!! Autocad will be the tool for the Cabinet design, I am thinking of two down firing woofers and a front firing 5" driver.
Maybe 2 eight inch instead of 10, I don't want the bottom of the Bass notes to sound like a sound track of the movie TWISTER LOL.

[phatcactus]

So inspired by this I was that I stopped by Radio Shack after school and picked up a piezo buzzer. Then I went home and looked at my bass and decided I simply cannot have the jack just dangling like some common slob! So in my doodling for a solution I decided a volume and tone knob would be nice as well. Then I went back to school, because they have a shop. Free sheet metal and powertools.

This is my first design. It's a little small width wise, and it could slide sideways and off the strings if it wanted. Next week I'll make an improved (and hopefully much less sloppy) version and wire it up.

Apparently I cannot upload pictures. :/
http://www.pedestrianisaprettygoodband.com/controls.jpg (74k)

[WOOOOMPH]

WOW that pic of the controlls looks real neat and tidy. Do you get any wolftones since you did that? Just curious, it looks great and un obstructive.

Just make sure you are aware I use a phantom power supply, look at the pics I posted there is a schematic there as well.
If you preamp has phantom power supply it may or may not work, That will be the fun part!!! Testing things out. Let me know how it goes. I got the best tone by putting the positive side of the pezo facing downward on the Table. The Smaller of the two wafers is the positive. CAREFULL YOU don't scratch the table of your bass. I dabbed the connections with a little quick drying epoxy and squished the tiny blob against a peace of wax paper so form a flat scratch free surface, but don't make a mess of the whole disc, keep the glue on the contacts and not all over the positive side of the disk.
I wager a bet here why I am having good luck is the un interrupted contact of the element [pezo] to the table. No materials are in between acting as a mute. That might be why I am not getting the traditional Tubby Woomph that other setups like this give.
Another note, I ripped the element out of the cheezy plastic black casing it comes in, this thing in the box looks like a car door open warning alarm, rip the disk out very carefull as not to bend and crimp it.
Good Luck
Scott Here.

[ChrisH]

WOOOOMPH, I too am planning on building my own amp/cabinet combo. I doing fine with the cabinet portion (using AutoCAD and WinISD) but I haven't solved the amp portion yet. Can you tell me about the Ramsey amps that you referred to?

Very cool pick-up.

[WOOOOMPH]

[quote=ChrisH]WOOOOMPH, I too am planning on building my own amp/cabinet combo. -snip to save----

Da$#$%mn They discontinued the high power audio digital switching line. My only hope for Ramsey is a distressed merchandise outfit such as Borges Le'Monte or similar company that sells distressed stuff, the only trouble is you have to buy a boat load of it. We have [at work] A huge catalogue of Electronics parts, kits, wholesalers and I even found the Digital AC switching power module for my Peavey Decca 1200 in there !! Peavey wanted 400 bucks to replace it, these guys sold it to me for 49.95, but I had to wait 8 weeks for it :-(
Better believe I WILL find a kit that will work, ebay has a few kits floating around out there but most are from dudes that BLEW the thing up trying to build it themselves.
My goal is to have a down firing woofer, front firing mid and a 400 watt rms power amp all in one neat but heavy little cabinet, Pre-amping is a trade that’s constantly changing with new technology so I will keep that External for now.
One thing for sure, with acception of New age materials such as Composite, / Aluminum-Mag etc.. Most cabinets that have weight move the floor under your feet a lot better, I don't care about a hundred pound amp, I DO care about size, I hate bulky appliances on stage.
I don't figure a guy like me that spends an hour a day in a gym working out complaining about a 24 pound amp versus a 35 pound amp, WHAT DO I CARE? A sling my 55 pound Steel Guitar in one hand and carry my 45 pound Peavey Nash 1000 in the other up flights of stairs in printers alley in Nashville all the time wile double parked.

Now if I could get RID of the cord between my Bass and Amp CHEAP, I'll have it made.

The witch-hunt for a kit begins here

[WOOOOMPH]

[quote=ChrisH]WOOOOMPH, I too am planning on building my own amp/cabinet combo.---snip2save----

Well here is an example of what’s out there if you have the patience .
The euro conversion plus shipping will bring this booger down to under 200 bucks, BUT it is an over kill with power, 400w rms? EEK!! The power supply is built in!
I am looking at 8” subwoofers, for a pair of 8’s will be “quicker” responding then a single 10, size is going to be small here.
http://www.bkelec.com/Diy/mf450.html

The MF 450 is available in a split transformer for 110 volt ac operation, The MFD600 is about 400 us dollars BUT tempting!
This is just the beginning Chris. See the pics I wont leave the pics up long, after I start a new thread I will pull them down.
Great source for speakers: http://www.bkelec.com/Professional/L...vers/pd/pd.htm

From now on, I will research more on amplifier issues but with start a new thread on “Home Made Amps” This thread was originally about a home made pickup and the subject content is drifting a tad too bit now !!! Look for the thread in the near future, let me study this challenge first.
Boy Ramsey had me spoiled.
Scott Clancy is my real name by the way, Woooomph is my reputation when I am playing the bass !!!
To save Bandwidth in this forum, feel free to email me at
cowboy6591-at-earthlink.net ya remove the -at- and replace with a @ SPAM BITES!

[ChrisH]

Scott, I look forward to the new thread. Sorry if I started to take us down a different path.

I see you're in or near Nashville. I don't live there now, but spent part of the '80's there.

Now back to your pick-up...

[phatcactus]

Bah! This thing rattles like all get-out. I blame the pots. But that's quite okay. Since I'll be needing a preamp anyway, I'll just take 'em off.

I still don't really understand what you mean by "phantom power." What is your circuit actually doing? Why's it necessary? Running the piezo straight into an amp seems to work just fine, although the tone bites. Does your circuit fix the ultra-high impedance, which I believe is the cause of my crappy tone?

Thanks. This thing'll be great once i get it goin'.

[WOOOOMPH]

--Snip2Save--------
Which I believe is the cause of my crappy tone?

When you plug it straight in NO battery, you are running a pezo for a magnetic or induction mic, when you use the circuitry I included you are running a Condenser element mic, BIG Difference !!
The Pezo is playing an entirely different role when in series with a phantom power circuit. Sudden changes in capacitance are what it is doing. The non battery method surcomes you to using a Pezo as a change in "Resistance" type of mic [like a minispeaker] or an induction type mic, Witch in any case a pezo is worthless for that. Pezos are very efficient at "Responding to sound waves @via capacitance change".
Capacitors need to be in an active [voltage supplied] circuit to do that. I have plenty of capacitors and resistors in my home lab, I can mail you the right ones pro bono if you need.
cowboy6591-at-earthlink.net
Thanks. This thing'll be great once I get it going'. [/quote]

[mje]

Originally Posted by WOOOOMPH

The battery is needed for as a pezo does have characturistics of an Electret element in such as the ones found in a computer mic<snip>...

Okay, there must be something I'm missing here. An electret microphone has an FET preamp built into the case, and that's what the battery is for- to power the FET. A piezoelectric element is not an active device- unless you have some special device that includes both a piezo element and a preamp of some sort. But putting a battery in series with a naked piezo element thorugh a capacitor won't do much of anything.

[Easy Rider]

I thought about this myself recently. I'm building an E-drum kit, and thought I might try those piezo elements on my acoustic guitar and my double bass, just for fun.
If it's really as good as you say, Scott, then it's the choice for a beginner's pickup. And who knows, with some more research into the placing of the element and the preamp one might give the pro manufacturers a run for their money. Sound-wise ofcourse, it won't look as good.
Never say never!
Heh, now I'm definitely going to fool around with those piezo's!

I agree with MJE though that an electret element is quite different from a piezo element, at least technically, but maybe the output behaves the same way? My electronics knowledge is still quite 'green'.
I'm looking forward to your explanation, then maybe I can put the Bass Max purchase off, at least for a while!
'Cause time to fix something up myself I got, money to buy stuff someone else researched and fixed up, nuh-uh.

Fascinating!

EZ

[mje]

Originally Posted by Easy Rider

...
I agree with MJE though that an electret element is quite different from a piezo element, at least technically, but maybe the output behaves the same way?...

An electret- and we're not talking about an electret microphone here, just a piece of a polymer with a chanrge permanently imposed on it- and a piezoelectric element have similar behavior in that bending either will result in a viltage, although the physics are different.

The big difference is that the electret microphone capsules that we casually refer to as "electrets" have a built in preamplifier/impeadance converter that needs an external source of current. Some have three wires- ground, audio, power. SOme only have two wires. The capacitor/resistor circuit in the earlier post supplies current to a two-wire electret microphone while blocking it form the amplifier, via a series capacitor.

A raw piezo element has no such preamplifier, and adding this DC-blocking circuit can only introduce distorion. Adding an FET preamp to a piezo element can be done, and was the basis of the FRAP pickup.

[Easy Rider]

Originally Posted by mje

The big difference is that the electret microphone capsules that we casually refer to as "electrets" have a built in preamplifier/impeadance converter that needs an external source of current.
[...]
A raw piezo element has no such preamplifier, and adding this DC-blocking circuit can only introduce distorion. Adding an FET preamp to a piezo element can be done, and was the basis of the FRAP pickup.

I read up a bit on electret microphone 'capsules' and indeed it's the FET that needs the current.
Furthermore, I don't think a piezo disc can hold any charge, so it can't really function like a condensor mic, can it?
So using the piezo in a 'standard' fashion seems to be the only useful way, but usually the sound (as Phatcactus found out) isn't that great.
But like Scott said, it sounding so good may be the result of his tight placement of the disc. Also, don't capacitors bleed out certain frequencies? Maybe the capacitor bleeds out exactly the nasal tones, making it sound good?

EZ