[sdiy] low voltage filters

[Tom Wiltshire]

Sorry, lowest voltage I've dealt with for audio is 9V stomp box designs. LM13700 works fine at 9V, and would make an SVF no problem. If others have run the chip at 5V successfully, then I'd have thought a 5V SVF is possible. Below that…dunno.
If not the LM13700, then I know the THAT2162 can run at 5V (ok, +/-2.5V). That'd make a good SVF.

Are there any single-supply VCAs intended for modern MP3 players or mobile phones that cope with 3.3V you could use? I don't suppose anyone intended them for making VC-filters, but it ought to be possible.

Tom


On 19 Apr 2017, at 20:38, Chris McDowell <declareupdate at gmail.com> wrote:

> Howdy list! 
> 
> Wondering if anyone is aware of, or has any tips towards, some low voltage VCF designs. I've seen reports of people using LM13700s with a single 5V supply for VCAs, and their one-off forum posts made them seem happy, heh. I realize this would have very little headroom. I've also checked out Hoshuyama's site, which has a few battery-powered designs. Some things I've considered: 
> 
> - Perhaps LM13700 just works at 5V ¯\_(ツ)_/¯ (avoiding breadboard as long as possible…)
> - Discrete OTA with BJTs
> - MS-20 Style, like the monotron 
> - Vactrol, H11F1, or similar 
> 
> The point of this is that I have DCOs and ADSRs working wonderfully in a 3.3V environment. Some dirt is okay, I say. Super ideally, I want to implement an SVF with a single 3.3V supply, suggestions toward reality / sacrifices are welcome. I imagine this would work fine with vactrols, but I don't want to design anything with parts I can't buy from mouser, hehe. 
> 
> Cheers, 
> Chris 
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