|
Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
|
Thread Tools |
29th May 2019, 4:11 pm | #1 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
ETI Wave (sound) simulator
Whilst tidying my old projects, I found a wave sound (i.e., the sound of the sea) simulator which I made some years ago. It was made by (amplitude) modulating white (or maybe pink) noise in various ways.
I gave away all my old ETI magazines, which is where it came from (I actually labelled the piece of veroboard) - so now I can't work out the connexions. I can easily trace loudspeaker, and power, but there were another few external controls for which I only have veropins! I'd be very grateful if anyone could identify the article (and hopefully I can then download it from the excellent American Radio History site). dave
__________________
Dave Teague |
29th May 2019, 5:45 pm | #2 |
Hexode
Join Date: Jan 2015
Location: Rustington, West Sussex, UK.
Posts: 384
|
Re: ETI Wave (sound) simulator
Hi Dave.
Circuit diagram I still have about 25 Pcbs for this project. They work very well. pm me for more info. Bob.
__________________
Bob, BVWS member |
29th May 2019, 6:05 pm | #3 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
Bob,
Many thanks - but that's way more complex then the one I made. It has a quad op-amp (TL084 etc) for the modulation, and a small class-B discrete amplifier for output; and a couple of discrete transistors for the noise source. Dave
__________________
Dave Teague |
29th May 2019, 8:44 pm | #4 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,575
|
Re: ETI Wave (sound) simulator
Dave, try 1997 issue 1 (January) Page 33 onwards:
https://www.americanradiohistory.com...97-26-No-1.pdf You didn't mention biofeedback in your OP but it has the two transistors as noise source, quad op-amp plus small amplifier IC structure that you mentioned. |
29th May 2019, 9:23 pm | #5 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,575
|
Re: ETI Wave (sound) simulator
Oh, wait, sorry you said a small class B -discrete- amplifier. That can't be the one, then. Try looking through this (almost complete) ETI index to see if you can narrow it down.
http://santaroga.xyz/2019/03/13/the-...ete-eti-index/ |
29th May 2019, 11:16 pm | #6 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
Many thanks for this link - I'd tried looking at individual ETI indices (which is somewhat tedious!).
But I still can't find it - names that might be the right thing led me to look at dec 95, dec 96, 97 #1, nov 87, dec 87, apr 82, may 82, apr 76, and jun 96. I suppose it's possible it was in a TechTips: I may try that route tomorrow. dave
__________________
Dave Teague |
30th May 2019, 6:46 am | #7 |
Nonode
Join Date: Jun 2016
Location: Bognor Regis, West Sussex, UK.
Posts: 2,300
|
Re: ETI Wave (sound) simulator
Although the schematic Bob posted may be more complex it is worth considering, I have heard it and it really does sound like waves gently lapping on a beach.
Peter |
30th May 2019, 7:25 am | #8 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,899
|
Re: ETI Wave (sound) simulator
The schematic Bob posted looks very good. It uses a PRBS randomiser to control the modulation so the waves don't come in with boringly metronomic regularity. Even the spare opamp section is properly parked!
If there are boards available, this one looks worth building. David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
30th May 2019, 11:30 am | #9 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
Thanks, all.
I have one wave sound simulator, and that should be enough (albeit I can't actually figure out the connexions yet)! dave
__________________
Dave Teague |
31st May 2019, 9:02 pm | #10 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,578
|
Re: ETI Wave (sound) simulator
|
4th Jun 2019, 10:18 am | #11 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
Well, I finally got to the bottom of this.
My labelling of the original circuit was clearly wrong. The circuit was from Elektor. I found a copy of it dated May 2011, but I'm sure the original was way, way earlier. I may search through my hard copies when I have the time, but for now I can connect up the veroboard + make waves again! Thanks, everyone, for your suggestions. dave
__________________
Dave Teague |
4th Jun 2019, 2:52 pm | #12 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
..actually, Feb 1996 appears to have the original circuit (referenced in the May 2011 magazine).
__________________
Dave Teague |
4th Jun 2019, 5:11 pm | #13 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,575
|
Re: ETI Wave (sound) simulator
[Rueful laugh]
When you first posted this query I went off trying to find your project in ETI but thought I'd kill two birds with one stone by looking out for an ultrasonic mains on/off switch project that I have fond memories of building - it was my first mains powered project and it very nearly killed youthful me, but that's another story. Anyway, I did find it eventually... in Everyday Electronics, not in ETI, where I was sure it had come from. But you said you had labelled your project as an ETI project, so I kept quiet about that. |
4th Jun 2019, 7:41 pm | #14 |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
SiriusHardware,
My apologies for misleading you. I think what must have happened is that in a previous fit of tidiness, I misremembered + hence mislabelled it; now some more years later, I can't even remember when I labelled it.... dave Mods: this can probably be closed now.
__________________
Dave Teague |
4th Jun 2019, 10:04 pm | #15 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,575
|
Re: ETI Wave (sound) simulator
Oh, no harm done.
I ended up finding my old project anyway, which I probably would not ever have done if I had not embarked on your quest initially. I was only admitting that I had, in fact, made exactly the same sort of mistake myself with regard to the project I was looking out for. |
5th Jun 2019, 7:25 am | #16 | |
Hexode
Join Date: Sep 2003
Location: Cheltenham, Gloucestershire, UK.
Posts: 298
|
Re: ETI Wave (sound) simulator
SiriusHardware,
Quote:
Strange thing, memory.... dave
__________________
Dave Teague |
|