Linkwitz Transform circuit using State-Variable filter

[shredhead]

I am trying to find a circuit to build a Linkwitz Transform using a State-Variable design. I am familiar with ESP's site and the spreadsheet things and have built a few of them with success but they have limitations on Q's and I think they are a bit on the noisy side.

What I want to end up with is an LT that had adjustable gain, frequency and Q. I know it is possible because Marchand electronics makes the bassis which does it and I THINK he's using a state-variable design because his has two pots that are double ganged and it looks like the right amount of op amps.

Thanks for any help in advance, I am too dumb to figure this out on my own with my limited resources.

 

[bjorno]

I am trying to find a circuit to build a Linkwitz Transform using a State-Variable design. I am familiar with ESP's site and the spreadsheet things and have built a few of them with success but they have limitations on Q's and I think they are a bit on the noisy side.

What I want to end up with is an LT that had adjustable gain, frequency and Q. I know it is possible because Marchand electronics makes the bassis which does it and I THINK he's using a state-variable design because his has two pots that are double ganged and it looks like the right amount of op amps.

Thanks for any help in advance, I am too dumb to figure this out on my own with my limited resources.

Hi shredhead,

Is 94 dB S/N good enough? Here is an example of an IMO better approach where you can enter all parameters in software but still is an analog solution:

http://www.cadarn.net/AES117Paper220.pdf


http://www.anadigm.com/_doc/PR0237E04-0001.pdf

b

 

[CharlieLaub]

never mind...

 

[shredhead]

Thank you Bjorno, you've given me something new to think about!