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I need a simple schematic that inverts, and/or lowers the pitch of an analog audio signal? Answered

My latest attempts with a bunch of Op Amps has failed again to give me decent results. I would like to be able to lower the voice of someone high pitched, in order to sound more like mine or lower.

Can anyone find a pin out and data sheet for the obsolete dedicated IC that does this, namely the WIN8072?


Thank you Cameron for the unscrambled datasheet. It will help a lot in my current project. It is too bad that I can't find a supplier for the IC except in those old kits.


8 years ago

Inversion sounds weird but it is simple, just use a pure tone oscillator of high pitch maybe around 2 octaves up from middle C and a ring modulator and an equalizer. Even weirder if you get it to lower the pitch because there will be a linear shift instead of a musical shift, and probably would require two of every circuit. To do musical note correct pitch change you need either granular synthesis or a digital convolution, although I described a possible analog equivalent in a similar question. (recording and playing a very small loop at different speeds at the same time works) New idea I haven't tried: using one phase locked loop to control another which is tuned to a different center frequency, because using binary counters as frequency dividers just turns sound into pseudorandom noise.

I know a LOT about creating noise unintentionally , believe me ;-)

I made a bat listener which divides the frequency picked up by a bat (40KHz) using a 4040 cmos chip. The chip is a binary counter so each pin divides frequency by two so depending on where you connect the output you can vary pitch. The sound is a bit crackly when it comes out of the speaker but other than that works well.

This is a link for datasheet for 4040http://www.9h1mrl.org/workshop/ChipDataEbook-1d/html/4040.html

For my circuit I had to run the signal from the microphone through two LM 386 chips to amplify it.

Did You do an ible on this? I can't find it....

No I didn't. I got the basic circuit diagram from a magazine and the circuit I ended up with was very similar so I was worried about posting an ible an the grounds that it's not really mine (not all of it anyway) and I could get in trouble regarding copyright. Maybe I'll post it in a few years time.

If you gave credit to where you got the design, and just showed how to make it (rather then claim it as your own design), that comes under the Fair Use act. But, if you are still reticent about publishing an ible, could I see the circuit (schematic if you have one)? If so, let me know here or in pm and I can then give you an email addy if you don't wish to have to publicized .

Thanks for reminding me of that, I had seen that earlier..but didn't really think about it at the time.

I hadn't thought to use the 4040 for this, I think I have a few in my parts bin.

Was the sound crackly after of before amplification ?

After. Before the sound was inaudible. I guess that doesn't help much.

Yeah, I was thinking I might be able to determine before working with it, what exactly the cause of then noise was.

did you try using capacitors and inductors? caps clip low frequency inductors clip high frequency if you use a cap and an inductor, you'll clip both high and low frequencies, leaving the mid ranges

It is ok. This is really a complicated system I am trying to make simple, and I am afraid I won't be able to. *sigh*
Clipped audio, especially a speaking or singing voice becomes garbled a bit if clipped, depending on how much it is clipped.

You see, I am literally looking for a way to alter the frequencies to one of the subharmonics or one of the superharmonics.

i have an idea.. get a voice changer and circuit bend it

I found an old kit I had, but it uses an obsolete IC I can't even find a Data sheet for the WIN8072 Sure, I spent nearly $69 for a phone that had the circuitry in it, but when I went to use it, the other party could not understand me at all (too much clipping, and garbled voice) and so I sent it back. I haven't seen the product in years (this was over 10 years ago I bought that phone).

It is a bit of a dilemma I am in.

That one uses the old WIN8072 chip. I can't find a pinout for it, nor a schematic

At your link, enlarge the picture


I have that. It was with the old kit I have too. Same thing. The schematic is for the voice changer, plus the amplifier, in kit form (PS: in case you don't recognize it, in the schematic, the side of the circuit with the LM386 audio amp on it, is the amplifier stage). I mean the Data Sheet for the WIN8072 itself, i.e. the spec sheet. It doesn't seem to be available, and it is listed in some lists as obsolete.

Ok, I will have to open that in IE when I get home, FF displays this:         !  "        "    "       #      ! # "#   # $   "         %    &  " '(  #  )

open with something OTHER then ie open with adobe acrobat reader it opens

I still need to go to the site, and it gives me that mess in FF. I will have to try a bit later, I am still trying to get CheckPoint online

Hey, if you can make this a separate post, it is at least an answer to the IC portion of my question :-)