New Linear Audio publication!

ditto.

so you know the next question, right?

how do we get one?
😀

mlloyd1

I am looking how to have a bunch of these made in an economical but controlled way.. Those regulator and converter chips cannot reliably be soldered for the average diy-er (or any diy-er probably!). So the only option is to offer this as a complete unit, fully assembled and tested, so you get a guaranteed working unit.

A group buy is an option, but to limit all the admin chores and make for a quick project completion and delivery, I am also looking at Kickstarter. They take 5% but it may be worth it.

I'll try to progress quickly so you can order as a holiday present to yourself 😀

Jan
 
I would like to test some polyphenylene sulfide SMT caps with Scott and Cyril's rig. I can see how you do this with the SYS2722, (Sine D/A Var Phase) but for those without, wonder whether an "all pass" filter will deliver the -90⁰ phase shift with sufficiently low THD to make it work.

A state variable oscillator can provide quadrature outputs, I think. I used two channels of a good sound card set in quadrature. I swept them in frequency to find the exact null (x Hz/sec from AHz to BHz and just measured the time to find the null) a trifle tedious but works. You might need a fine and coarse sweep if the first is way off. It's a vector subtraction so the null is quite steep close in. CoolEdit does all this easily from the make tones menu.

I didn't push the sound card measurements as hard as Samuel did in his presentation and I don't know (doubt) it would go to -150dB.
 
Last edited:
I would like to test some polyphenylene sulfide SMT caps with Scott and Cyril's rig. I can see how you do this with the SYS2722, (Sine D/A Var Phase) but for those without, wonder whether an "all pass" filter will deliver the -90⁰ phase shift with sufficiently low THD to make it work.

I am negotiating with Cyril's son to get hold of his father's test equipment, I'll let you know if it pans out.

Jan
 
Yay. Well I can't afford one for a few months (daughter #2 to uni), but have chucked a few coppers in to get you going. Fingers crossed you hit the target.

Are you averse to the word being spread around about this. Given your name is inextricably linked with DIY regulators...