Tone Deaf

On 02/07/2020 at 07:26, itu said:

I took a quick look and the circuitry is based on a FET (2N5457; these have very high input impedance by nature), and I have a hunch that this might work.

About immersion: nearly two decades ago I was a bit involved in a research project, where big piezos where studied. They were something like over 10 mm thick. Impossible to get, because they were meant for very low speed communication between submarinesor like. The result: no project output because of the costs and availability. Those were the days.

Hey Itu. Thanks for having a look at the circuit mate. Based on your input I feel more confident about building this. WOW I can't imagine a 10mm thick piezo actually vibrating. I love your whimsical comment.... "those were the days" If you'd care to share some memories I'd be fascinated to hear them. At this point Ohms seem almost redundant so.... one last. Thanks Ito.

On 02/07/2020 at 12:32, bertbass said:

 

On 02/07/2020 at 12:32, bertbass said:

Good luck with this and I'll be following it to see how successful you are.  It's a road I went down a few years ago but could never get to work properly. 

Hey bertbass. I'll keep updating once I start experimenting. Building does rely on the delivery from China of course. If you'd care to share what didn't work I'd be very grateful so I don't start down roads that might not connect (dead ends). Also any plans, circuit diagrams, observations and details of what did work would be great. 

Of course I know I'm asking a lot. Whatever you decide is great mate.

2 hours ago, TwoTimesBass said:

+1 for itu's suggestion, keeping the preamp close to the transducers is good practice, and good advice in the rest of the post too.

If your piezos don't come with a spec sheet, then I guess given the amount you have coming, just experiment to your liking. The benefit of the piezos is that they are pretty robust electrically and mechanically...

I look forward to seeing/hearing what you come up with 😀

Thanks TwoTimesBass. itsu is very cool and current...ly has 7 Ohhmms. If my order ever arrives (from China) I will have a lot of fun experimenting. They cost next to nothing and the applications seem, in part, only limited by ones imagination. If only I'd been more of a geek in school. Anyway, two more for sticking with it. Thanks TwoTimesBass. 

2 hours ago, itu said:

Usually FET-based preamps and opamps have so high input impedance that a piezo output is not an issue. I have found out, that the old t c electronic SCF can eat any piezo with ease. Keep the wires short, high impedance is prone to interference.

The size (diameter) affects frequency response. Very roughly a larger sensor produces more low frequencies and a smaller will be better with higher frequency content. Don't you worry 'bout a thing: your disks are pretty close in size with each other.

FET is a type of transistor yeah? What's the difference between a preamp and an opamp and should I consider one over the other? Thanks for the advice re the diameter. I'd kinda guessed that might be the case but as you've mentioned it, I have seen 50mm piezos. Do you know why you wouldn't produce an array with say 20mm and 50mm for say an acoustic bass? would that be something to do with the phase discrepancy as mentioned by TwoTimesBass? Thanks everso much for your time itu. Fantastic advice written in a way that I can at least grasp the concepts. For your awesomeness and the way you got me to spill some guts you have ascended to the level of 7 Ohms. Nice one. Thanks mate. BTW. Did you have a look at the diagram I uploaded?

2 hours ago, itu said:

First of all, I cannot see the need for more than one or two piezos. One/two piezos under the bridge, and that's it. If you want to use several, consider both placement and active mixing.

They can be pressed a lot (make a tiny cavity under the bridge or put one to the neckpocket), but bending kills these fragile parts easily. They are usually glued to brass disks and pre-soldered with short wires (buy these!). If your deal includes disks without wires, I would strongly suggest metal pogos or springs instead of soldering. The lead-titanate material tends to melt accidentally and soldering them is really difficult to master. Believe me, I have tried it several times in professional surroundings.

Thank you itu. You know what it's like, you start Googling a subject and it runs away with you... it does me any way. So in short I started looking at miking up my acoustic guitars. I've come back to music after a generation away (Children and making money for the Man). I downloaded Audacity and Hydrogen to get started and just got carried away. Anyway long story short, started thinking about percussion, drums etc. and one thing lead to another and I got to thinking about something I wrote donkeys years ago.... kinda had an aquatic theme. So there's immersion at one point, and logically I guess, emersion. Anyway I hope that partially explains my fixation with piezos. I didn't fancy soldering tails to the things so I bought pre soldered with 6" tails.

That looks like a great piece of kit TwoTimeBass. I ordered 10 Piezos @ 20mm and 10 @ 27mm a couple of days ago. I am a total tool tart but draw the line at an oscilloscope (at the moment at least). I do have a multi-meter. Would I be able to establish the impedance of the transducers with that or is it more of a moving picture whilst the transducers are being excited by a signal? Ooo errr Mrs.

If anyone's interested here's a link to the pre amp build I found. https://www.instructables.com/id/Guitar-Contact-Microphone-Preamp/

5 minutes ago, TwoTimesBass said:

😀 6 Ohms... I like it! Always thought of myself as a low-impedance kind of guy 😂

You and me both mate.

12 minutes ago, pete.young said:

A piezo typically requires a very high impedance pre-amp. An absolute minimum of 1 MOhm, more if possible.

Hey Pete Young. Thanks for taking the time to read the mini thread and contribute mate. So I'm kinda wanting to build something myself and have seen this on Instructibles. What do you reckon? I'm still thinking of connecting multiple piezos probably 3 or 5. If connected in parallel as suggested by TwoTimesBass, above, would this be appropriate then? As you are suggesting MegOhms you have been awarded 6 Ohms as well. 

Flippin' 'eck TwoTimesBass. Thank you so much for taking the time to reply with such clear and concise answers to my questions. You clearly are an expert mate, at least in comparison to me..... and a large percentage of the rest of the planetary population. For this reason you are awarded 6 OHMS !  OHHHMMMMMMMMMM.

Hi Guys.

Anyone any good with electronics and amplification? Please be gentle with me as I have very little experience when it comes this.

I have some questions regarding piezo transducers used as contact mics. I’m interested in various applications and am thinking of wiring three and five piezos together.

Am I right in thinking that piezos produce a relatively high output voltage but extremely low ampage and is this why piezos require a preamp?

How should they be wired together series or parallel? If parallel and on the same instrument, or environment recording the same source, will the increase in the power output of the ‘array’ be enough to negate the need for a preamp before amplification for headphones?

If you’d still require a preamp, could you use the same one for 1, piezo on it’s own, and / or 2, 3, 4, 5 piezos wired together.

Could you Bluetooth from a preamp to a monitor or Bluetooth headphones or would the signal have to go through an amp first? I’m sure answers will generate more questions so your indulgence is appreciated. Thank you kindly troops. 

Hey Lee. Just joined myself mate. looks like a great site. I've had some useful support already. Here's one for you. Not too sure about the colour but I hear America are very keen to do a free trade deal with the UK. Can't get cheaper than free. 😉 https://www.ebay.co.uk/i/173951607338?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=173951607338&targetid=879842586457&device=c&mktype=pla&googleloc=9046426&poi=&campaignid=9445986154&mkgroupid=95782681917&rlsatarget=aud-629407027105:pla-879842586457&abcId=578896&merchantid=6995734&gclid=Cj0KCQjwn7j2BRDrARIsAHJkxmwPiDSvCUuFTXu646rV-AJEGu5EycNAvef1KBCdo2ji687wtMjKDbsaAtYjEALw_wcB

22 minutes ago, JonnyBGood said:

Hi folks

I'm about to buy a bass again (probably Marcus MIller V3 2nd gen) after a hiatus of several decades and found this site when looking for info/reviews. Have played guitar for 40 years, fronted a band as bassist/vocalist many years ago, worked as a classical/Spanish guitarist for about 17 years and packed that in last year...

Anyway,  apart from a keen interest in modern acoustic fingerstyle guitar I feel the groove of bass beckoning again.  Hopefully you guys can help me with some questions about doing stuff at home 🙂

Cheers

Jon

Hey Jonny. Same as mate. Coming back after decades. Just setting up some basic multitracking laptop stylee in a corner of the kitchen diner then I'll get cracking on. Good luck mate.

5 minutes ago, Tone Deaf said:

Hey Rabbit. No mate. I haven't heard of this. But I just followed the link and Windows defender threw up a warning about accessing further and the possibility of damage to my PC. 

OK mate. I went at it from a different angle and got through. Thank you.

4 hours ago, Rabbitcandyknob said:

Have you looked at stewmac. For those bass cabinets you want to build

StewMAX 1-Year Membership | stewmac.com 62 B · 1 download

Hey Rabbit. No mate. I haven't heard of this. But I just followed the link and Windows defender threw up a warning about accessing further and the possibility of damage to my PC. 

11 hours ago, Dad3353 said:

Good evening, TD, and ...

Plenty to read and amuse you here, and lots to learn and share.

Thanks Dad.

Hey Teebs.

22 minutes ago, baldwinbass said:

Hi Tony 👍

Hi Baldwinbass. I just got through reading the Rubis cab build thread. Fantastico. Glad I joined.

16 minutes ago, SpondonBassed said:

Welcome Tony.

B15N style cab build FINISHED!

Two 1x15s?

17 minutes ago, SpondonBassed said:

Welcome Tony.

B15N style cab build FINISHED!

Two 1x15s?

Thanks SpondonBassed. Yeah 2 Cabs. I dunno. In my head it'd be more versatile. I could move one very, if say I wanted to take one to a friends for a bit of a jam and a few beers more easily than a 2 x 15. They could stack or spread in the event of going into a rehearsal studio with one of those noisy loutish drummer types and a Jimmy Page lookalike. And having started to read a bit about ported and sealed cabs i could make one of each. I need to look into this a lot more. Thanks for the link mate. I've had a quick scan and it looks really good. I'll have a good read later on with a pint.

Hi Troops. I am coming back to my bass guitars after a long, long lay off. I have an old Gibson Grabber and a Westone Thunder 3 fretless. I'm a bit all over the place at the moment with various workshop projects, fishing, bait making and the music. I've downloaded Audacity for recording and Hydrogen drum machine for the drummy stuff. I'm making a shelf at the moment for the last bits and pieces like the interface for the laptop. That's a Lexicon, and then I can get started. I bought a cheap practice amp a while back but it sounds so bad that it pulls the fun slider down to zero when playing through it. So here's the rub... I have a couple of 15" Celestion bass speakers I bought 30 years ago. At the time I built a 2 x 15 cab for them but it was so big and heavy I took them out and recycled the cab and the speakers have followed me through life ever since. I've kept the old Marshall valve amp and now want to build a couple of smaller enclosures for the Celestions. I have been searching for Cab plans, designs and am getting nowhere. What's the best way to search the site for info as my initial attempts have produced a  very diverse set of results. It'd be good to narrow them down a bit, and what's the best way to ask for advice and suggestions? Basschat looks great and I'm looking forward to being a nuisance in the very near future. Cheers Dudes. Tony.