LDR Sweller

[Kipper4]

This has been on my mind for a while
A work in progress

It takes advantage of a non inverting op amps gain set up to make notes swell
All input welcome
Unless your handle is MojopopKorn. Just kidding
A big thanks to Dead Astronaut (for his revised Phuncgnosis envelope detector (originally Tim Escabedo)
Duck Arse for his continued support
RG and Goucho for there input here and so so much help over the last 3 yrs
Same goes for everyone else.

http://www.diystompboxes.com/smfforum/index.php?topic=113261.msg1048016#new

Heres the 5th revision

picture deleted

[Kipper4]

oops C6 is not needed
and C1 is a 1uf electro.

[Cozybuilder]

Hey Rich- It looks interesting, will have to bread this one.

[Kipper4]

Geez I hope I have transcribed it well from the breadboard.
Let me know how you get on Russ

I'm using an NSL32 vactrol for the breadboard.

[vigilante397]

What value of LDR are you using? With 2.2M as the input resistor it looks like you're not trying to get a ton of gain, just a bit over unity?

Really neat idea, love to hear some samples

[mth5044]

I use a TV screen for a monitor and I still can only see 15% of the image at a time 

[Kipper4]

Sorry Nathan and Myth.
I'm still not to good at the pic thing. I figure at least I got an image up in the post

Vactrol is an NSL32 Nathan

[lars-musik]

AHHH! I won't be home for some days, what a shame! Maybe this is it, finally! Advance praises from me to you, Rich!

And so few parts, this will not even be a challenge to put it in a 1590a. Maybe I should even look for my breadboard on my messy workbench for this one.

BIG THANKS for your efforts!

Lars

[Kipper4]

Lars you are welcome my friend it's a pleasure to be able to contribute something that I haven't seen before.
I hope you like where it's upto so far.
It's not without its problems but it's a long way on from the initial idea.
Good luck finding the breadboard.......😀

[blackieNYC]

Nice! Are we talking about backwards sounding swells? Like a Gator or a Slow Gear? How does it compare?  Note comes up from nothing, and the attack of any note played before the release is heard but if you time your playing right....   Pardon the interrogation. You know what I'm talking about!  It's just that I'm doing that cartoonish violent-head-shaking followed by a wide-eyed "whuUUH?"

[Transmogrifox]

Sorry Nathan and Myth.
I'm still not to good at the pic thing. I figure at least I got an image up in the post

You can use the BBCODE tags to make the image display smaller:

Code Select Expand

[img width=600]http://i.imgur.com/K9BBj87.png[/img]

Like this:



More here:
http://www.bbcode.org/examples/?id=10

[Kipper4]

Here we go I forgot something already a 1n914 from C4 cathode / Attack pin 3 to gnd.
Sorry guys

Edit
The 1n914s anode goes to Gnd

Thanks Tranansmogrifox I couldn't remember how to do it. I've been trying hieght=.
Doh

[Transmogrifox]

Yup, the 1N914 makes all the difference.

Looks interesting. If you find the LDR is not filtering the AC noise enough you can change around the envelope detector a bit so that you're always driving the LED with more of a filtered DC current.

As it is my guess is the 1/2-wave ripple will be inaudible.

The buffer would not be needed if you feed IC1 B at the + input through C3.  Then you can just eliminate the extra IC and do the same thing with just one dual op amp.

[bluebunny]

I've been trying hieght=.

Height= also works, but you have to spell it correctly.   

[deadastronaut]

cool....nice one rich, good to see something new...

love a swell with delay...

now make it go backwards too..

[Kipper4]

Demo uploading to youtube as I write. I'll leave a link later same goes for the Downtime gate
Haha guys
Ill see what I can do about reverse later Rob


Ammended schematic here



https://youtu.be/Igz9l7Ng7ZE

[lars-musik]

Yuphii!

[garcho]

looks good Kip!

that op amp envelope detector is what i use all the time. good for you, to credit it to peeps here on the forum, but it is basically "textbook". just sayin' that so those reading know that they don't have to feel sleazy using that for their own projects

you can probably get rid of C8, and to properly terminate the unused op amp, tie the + to VB, not ground. Or, use that spare op amp to buffer the VB (connect its + to the junction of R12 and R13 and its output becomes the source of VB for the rest of the circuit).

[Kipper4]

Good one Garcho
I'll bare it in mind

[samhay]

Cool.

A few thoughts:
PAD should be connected to Vb rather than ground.
R12 is redundant if you are using a TL072, and you don't need R9 either.
I think others have pointed out that you could do away with IC1A without any real detriment.