Jim Williams designs a new Super Oscillator

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I have used some AP kit and its awsome, too expensive to have at home though and a PC sound card can do the same mesurments with less conveniance as the cheaper units. The artical claims the oscilator in the AP hardware is lower noise still and adjustable?!?!
 
Bob's comment is like mine, I squeezed -150dB out of my old Sound Technology 1700B in 1992 with a few tricks (good enough for me). I talked with Jim about "distortionless" oscillators with distortion trims last time I saw him. If you can get a copy of his AES talk and especially his references you can get the whole story. It turns out, in my case, the way a Wein bridge "really" works was buried in an obscure text book I had at MIT. Jim's reference from HP labs covering the same issue is in his words, "The best piece of engineering he has ever seen".
 
Jim sent me a copy of the article. It was Bernie Oliver's cover article in the Apr.-June 1960 issue of the HP Technical Journal. The gist is you can't simply make a distortionless Wein bridge oscillator. Bernie argued one way and my text used it to explain the usefulness of Volterra math (comming essentially to the same answer). I can't wait to see the latest incarnation, I'm sure Jim has a few secret rooms with virtually unavailable exotic components.
 
Bob's comment is like mine, I squeezed -150dB out of my old Sound Technology 1700B in 1992 with a few tricks (good enough for me). I talked with Jim about "distortionless" oscillators with distortion trims last time I saw him. If you can get a copy of his AES talk and especially his references you can get the whole story. It turns out, in my case, the way a Wein bridge "really" works was buried in an obscure text book I had at MIT. Jim's reference from HP labs covering the same issue is in his words, "The best piece of engineering he has ever seen".

Is that "Modern Perspectives on Hewlett's Sinewave Oscillator" from the 125th convention?
 
carpin, I'm not quite sure why you're quoting me and the linking to this thread. Yes, I can read, and yes, I have read the whole thread from the start.

I was commenting on post no.8, by klewis:-
Not being able to aford an AP just yet, can anyone point me to an article, book or reference on how to use a scope in crossplot mode to measure distortion?

If you look at the OP's EDN link and scroll down a bit, you will see the following comment by Bob Pease:-

Bob Pease commented:
I have been measuring op-amps with -159 dB of distortion, using an old Tek 2445 ANALOG Scope in Crossplot mode. I do this on the bench in my office because I don't have any A.P. equipment. I'm pushing past -164 dB next. / rap

I was merely pointing out what I thought the source of Bob Pease's comment may be, to try and assist klewis.
 
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