Interesting Read in Feb. Widescreen Review

[JonMarsh]

If you're curious to have some insights into the experiences and thinking that drives some of the "nutcase" companies out there (Theta Digital, Ayre, Cardas, BAT), as well as the more oddball music/gear lovers (moi, of course, being a card carrying member) you might want to check out the article

Theta Digital's Philosphy-

A Conversation With Theta Digital's Founder & President Neil Sinclari & National Sales Manager Mary Cardas


The article pretty much follows the descriptive title- and yes, Mary Cardas is formerly of Cardas Cable, being related to the founder, and obviously rather steeped in this audio stuff.

Though there are some "simplifications" in their description of some phenomena and the causes, for the most part I have to recommend this article to anyone wondering what the next level of reproduction is, and what may be holding their current system back. There's a lot of hard earned expereience and knowledge mixed in with the self promotion.

Give it a gander- I think you'll find it interesting.

Best regards,

Jon




Earth First!
_______________________________
We'll screw up the other planets later....

[Huskerduck]

I dont get widescreen review how about filling us in on some of the goodies




Mark


Ducks Meager Theater

[Lex]

yeah, I don't subscribe either. Pick one up occasionally, which month is this Jon?

Lex

[JonMarsh]

This is in the February issue. Widrescreen Review is probably the most technically detailed HT/Video mag on the market; some of the best reviewers from "The Perfect Vision" are writing for them now, inlcuding Bill Cushman.

In this article, Niel and Mary talk about how Theta has come to their current design and build philosophy; why they've found a variety of factors necessary:

• Muliple points of regulation with multiple power supply sources
  Isolated digitial, analog, and video grounds
  Resonance suppression in chasis
  Balanced differential DACs and analog circuitry
  Non Loop feedback analog electronics
  Using semiconductors optimally more important in most cases than the type of semiconductor (MOSFET vs. BJT, for example)
  Materials in passive components have a pronounced influece on the sound, even down to the PCB material chosen- probably a function of dielectric constants.
  Listening tests were the final judge of success in circuit designs
  

What was interesting to me about the interview was how easily their responses could have been interchanged with those of a friend of mine, Charles Hansen, the designer for Ayre Acoustics.

Some of the responses *did* seem pitched down a little for the magazine article, and occasionally had some simplifications I'd take issue with, partly because in some cases I don't think we really know *why* some approaches sound better.

For example, they talked about circuits using feedback, that it was the impossibility of the error correction coming back in time with the original signal for it to work well. Now, when you'r dealing with wideband power amps with a small signal response to 1.5 to 2 MHz, or high performance op amps with 100 - 250 MHz bandwidth, it's hard to make a plausible arguement that they aren't fast enough in the control loop for signals toping out between 20 and 50 kHz. However, even the best sounding commerical op amps (say, an Analog Devices AD825- very fast, settling time <150 nsec) don't sound as harmonically and dynamically right as a well designed class A zero feedback circuit. (I'm sure more than a few will pooh pooh this, as I tended to ten years ago, but even I've come around after a lot of listening tests and design experiments). I don't think we really know why. In the article, they admitted that where the art comes in is fining out about things that *don't* necessarily follow logically, but which work nonetheless.

Then, on another topic, something that does follow logically, and clearly works, is balanced power. After discussing this with ThomasW for a while, he's been evaluating some BPT units, both in the audio system, and even on his 32" TV in the family room. Tom is, shall we say, a convert. If you try it, you may be, too. I think he'll be filling in the forum soon about his experiences.


Best regards,

Jon




Earth First!
_______________________________
We'll screw up the other planets later....