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Old 11th November 2012, 05:20 AM   #61
balerit is offline balerit  South Africa
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Quote:
Originally Posted by danielwritesbac View Post
Okay I re-did the Full Wave type sensor for a bit louder bass.
Full wave bridge rectifier at speaker jack running:
1n5819, 3.1v LED, 3.1v LED, 3.1v LED, 390 Ohm resistor, LDR's LED
22uF cap paralleled directly to only the LDR's LED.

The ~3.1v led are InGan White or warm white LED that stumble across their knee voltage (better bass than the fast attack of zener). You'll get quite the light show. The resistor drain can be 390R to 470R. You can add more or less 1n5819 (schottky) to fine tune.

Ooh, an actual limiter that really rocks. Thanks Godfrey!
Is this reflected in the schematic of post #1?

Mac
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Old 11th November 2012, 05:57 AM   #62
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That version is the schematic at the top of post 1.
That's the rowdy volumax like boost (really rocks) for TA2020
I have changed only one thing since that publication--I'm now using an MR fast silicon diode instead of the 1n5819.


P.S.
Elvee's more refined version is explained at post 58.
Amplifiers and LDR's are all different, so choose whichever schematic you like best.
It is easy to try both versions, since the parts difference is a cap and a resistor.
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Last edited by danielwritesbac; 11th November 2012 at 06:05 AM.
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Old 11th November 2012, 10:00 AM   #63
balerit is offline balerit  South Africa
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Quote:
Originally Posted by danielwritesbac View Post
That version is the schematic at the top of post 1.
That's the rowdy volumax like boost (really rocks) for TA2020
I have changed only one thing since that publication--I'm now using an MR fast silicon diode instead of the 1n5819.


P.S.
Elvee's more refined version is explained at post 58.
Amplifiers and LDR's are all different, so choose whichever schematic you like best.
It is easy to try both versions, since the parts difference is a cap and a resistor.
Ok, thanks a lot.
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Old 23rd November 2012, 07:51 AM   #64
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New information added:
Some high performance optocouplers resistance goes to almost short (high dynamic range); however, the opto used in the schematic at the top of post1 didn't have that capacity. To adjust, you might want to employ a 1k trimmer as a variable resistor placed in series with the optocoupler's resistance.
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Old 26th October 2013, 10:46 PM   #65
udailey is offline udailey  United States
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Daniel
I like your idea. Its to easy to not try... if I played music really loud. 96db speakers mean I dont clip.
So one question and one suggestion.
What LDRs go to almost a short? I get about 40 ohms on NSL32SR2 as you know.
There are other optocouplers that work just like a resistor. Meaning that signal can flow both ways without being turned to DC like a lot of transistor based optocouplers. CPC1017 and a lot of others by Clare/IXYS are super cool little guys that have back to back mosfets and let me guarantee you they sound great. When I use them they have between 4 and 7 ohms resistance.
What I was thinking is that you could have three filters on the input going to ground. You have a treble/bass/midbass filters. Each filter employs a CPC1017 instead of a LDR. At the output you have the same filters. Now you only clip the offending frequency range.
Yeah its more complicated and your original already gets the job done but everyone else got to have their say and I felt left out!
Really I just wanted to commend you on your cool circuit and share that CPC1017. I highly recommend using it in the signal whenever you feel like you need an on/off switch. They are cheap and totally transparent with no distortion that my AP can see.
Uriah
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Old 2nd March 2014, 10:12 PM   #66
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Quote:
Originally Posted by udailey View Post
Daniel
I like your idea. Its to easy to not try... if I played music really loud. 96db speakers mean I dont clip.
So one question and one suggestion.
What LDRs go to almost a short? I get about 40 ohms on NSL32SR2 as you know.
There are other optocouplers that work just like a resistor. Meaning that signal can flow both ways without being turned to DC like a lot of transistor based optocouplers. CPC1017 and a lot of others by Clare/IXYS are super cool little guys that have back to back mosfets and let me guarantee you they sound great. When I use them they have between 4 and 7 ohms resistance.
What I was thinking is that you could have three filters on the input going to ground. You have a treble/bass/midbass filters. Each filter employs a CPC1017 instead of a LDR. At the output you have the same filters. Now you only clip the offending frequency range.
Yeah its more complicated and your original already gets the job done but everyone else got to have their say and I felt left out!
Really I just wanted to commend you on your cool circuit and share that CPC1017. I highly recommend using it in the signal whenever you feel like you need an on/off switch. They are cheap and totally transparent with no distortion that my AP can see.
Uriah
Thank you very much!
The 40R is okay. Those will work. Did you try a clipnipper? Blow up the plaster?

Got schema??

I've been trying to imagine how to use a jfet as an on-demand variably resistive load instead of the optos, since all we're doing is fluctuating the input load at threshold and with delay cap. I wonder if there's a way to use the CPC1017 like that?

DA (dual asymmetric) option is finer than symmetric. This takes two units. There's just a half wave rectifier (one power diode, not four) and the circuit is otherwise similar. The second unit has the diodes flipped the other direction. Music is strongly asymmetric in nature, thus a Dual Asymmetric causes much less distortion, but at the cost of almost twice the parts count. This also solves the problem of weaker optos, since if the amp clipped badly, it would max out both of the optos in parallel to the input load.
I think that Future clipnippers and similar circuits should all be made dual asymmetric and not use any bridge rectifiers at the outputs of audio amplifiers.
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Old 3rd March 2014, 01:48 AM   #67
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Default Rockbox? Maybe you're sitting on it? Android. . .

This is an attempt to answer that question about frequencies versus compander. There's a few practicalities. It would be good to keep the bass naturally proportional to the midrange and treble, and that does not require a lot of contouring efforts. Recently, RockBox has been ported to Android as an application. And, that makes it easy to preview some of the options digitally.

Rasher's Rockbox related stuff - daily builds of Rockbox for Android
The 240x320, 320x480 and 480x800 files for phone and (scroll down farther) the 800x480 is useable for tablet.
For reference, music is normally located at ./sdcard/music on android.
For reference, you can set the font size within the rockbox software under settings-themesettings-font.

For reference, here's the compressor settings that are similar (but not quite as good as) the clipnipper:
Threshold = -6 (clipnipper's led string)
Makeup Gain = OFF (boost, yes, somewhere else)
Ratio = 2:1 (clipnipper's voltage divider)
Knee = Soft (led string's soft knees)
Attack Time = 15 ms (or more) (clipnipper's delay cap)
Release Time = 400 ms (clipnipper's delay cap)

Install rockbox first and then. . .
Here is a config file with settings and eq'ing, expander and compander already set up.
Right click (long touch), and "SAVE AS" (save link as)
http://startfetch.com/daniel/config.cfg
You can simply drop it into the ./sdcard/rockbox folder.

Disclaimer: Headphones recommended for that--little built in speakers in a smartphone might explode.
This not expensive! Newegg.com - sennheiser earbud
Sennheiser MX365 can be upgraded by using a paper punch on the foam pads to create "doughnut pads" and just put the factory perfect hole at the driver grille. Like most earbuds, they'll need a push for bass. Therefore the config file.

And the point: I am not familiar with any reason to put the frequency response out of proportion in a compressor, expander, or compander; however, there ARE some frequency response options in the RockBox software's compressor. Those are the ones that I assume might be applicable to audio.
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Old 3rd March 2014, 03:29 AM   #68
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I take it the clip nipper can be a little abrupt, but appropriately so and this is why you want a jfet to act as variable resistor which is just what they do. I think you could get an idea by reading the TI pdf on transconductance amps. Just a jfet from signal to ground with a pot from signal to the base might give you some of the effect you want. Or you could use a transconductance amp driven by a voltage divider on the output of your amp to power the ldr. Then you might get real smooth clip nipping.
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Old 3rd March 2014, 04:19 AM   #69
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Hey, these 50R~100K LDR's in your store look quite suitable!
LDRs Light Dependent Resistors Silonex NSL-32SR2
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Old 23rd March 2014, 08:51 AM   #70
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Udailey, Feel free to produce the ClipNipper and/or preferably the higher performing ClipNipper DA (higher fidelity, twice as many optos, no bridge rectifiers) for nonprofit and/or profit use.

I have always been convinced that volume controls *should* result in effective concert sound if turned to max.

P.S.
In other news, simple, dynamics promoting power supplies really do exist.
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