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DIY Stompboxes => Building your own stompbox => Topic started by: ExpAnonColin on February 10, 2004, 10:27:10 PM

Title: BA6124 envelope filter
Post by: ExpAnonColin on February 10, 2004, 10:27:10 PM
(http://experimentalistsanonymous.com/images/schematics/5stagefilter.gif)
NOTE- I have NOT built this circuit.

Any problems/recommendations?  You could get quite interesting results by changing the various frequencies of each of the "stages", but you'd have to keep in mind if it was doing highpass, it'd only go as high as the highest stage, and same for lowpass, if you know what I mean, since all the lights go on and not just one.  You could also create quite a nice compressor with this chip (coming soon.)

-Colin
Title: BA6124 envelope filter
Post by: mattv on February 10, 2004, 10:35:23 PM
So you'd have one filter for each LED? Very interesting...  :)
Title: BA6124 envelope filter
Post by: Peter Snowberg on February 10, 2004, 11:52:43 PM
That's a very cool idea. I like the idea of a 'posterized' envelope filter.

One question... When are you going to build one? ;)

Any source for the BA6214? I suppose you could always adapt an LM3915 or LM3914 too.

Great idea though! I like it!  :mrgreen:

Take care,
-Peter
Title: BA6124 envelope filter
Post by: Tim Escobedo on February 11, 2004, 12:05:56 AM
Why reinvent the wheel?
http://stomper.hp.infoseek.co.jp/my_schematic_pic/fifth%20element.gif
Title: BA6124 envelope filter
Post by: tomtom on February 11, 2004, 12:36:46 AM
QuoteWhy reinvent the wheel?
http://stomper.hp.infoseek.co.jp/my_schematic_pic/fifth%20element.gif

I have this one on my computer for a while, still I can't see how it may sound.
Any idea ?

Tom[/quote]
Title: BA6124 envelope filter
Post by: Paul Perry (Frostwave) on February 11, 2004, 01:05:21 AM
Since the current to ground via pin 4 will vary depending on how many leds are lit, perhaps that could be used to vary the impedance of a transistor, like in some wahs based around a twin tee filter.
Title: BA6124 envelope filter
Post by: ExpAnonColin on February 11, 2004, 08:01:07 AM
Quote from: Tim EscobedoWhy reinvent the wheel?
http://stomper.hp.infoseek.co.jp/my_schematic_pic/fifth%20element.gif

Because I was unaware that the wheel had already been invented.  My bad.  I'll probably build one this weekend.

-Colin
Title: BA6124 envelope filter
Post by: Elektrojänis on February 11, 2004, 08:47:48 AM
Quote from: Tim EscobedoWhy reinvent the wheel?
http://stomper.hp.infoseek.co.jp/my_schematic_pic/fifth%20element.gif

Wouldn't that be a bit different than Colins idea in the first post? Colins idea seems to be to vary the levels through filtters with static cutoff frequencies. this other one has bandpass filtters where the cutoffs vary. Did I misunderstood sething?

Both should be interesting though.

Btw. Even though the filters in that fifth element one are all tuned for different cutoffs (by different caps) I think it would be interesting to have them tuned to same cutoff with the cap selection. After all... They are not moving at the same point at the same time... Right?