Discrete Opamp Open Design

Disabled Account
Joined 2012
IMHO, all have various pros and cons, but if I had to build yet another line-level discrete-opamp to actually listen to music, I'd probably go with a Kaneda/Constellation derivative, despite the fact that it's not an ultra-low THD contender. Why? Because it's simple and only requires a few parts to be matched, and by most accounts, has clean wide-open soundstage and resolution.
I've seen it. Used a similar but improved version for a passive RIAA phono preamp - decades ago. I like the newer designs -they are better, more refined performers and some are simple as well.
 
Breadboard, Bench

Not that ugly...
 

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Also one of our listeners finds my avatar offensive on religious grounds so I will change it but that needs great care...

No need to change it - anybody can use Hindu iconography without any fear of retribution, divine or earthly. Lord Shiva bears no ill-will to anybody for the use of his likeness, which in this case appears to be of early 20th century origin - the only possible objection could be on copyright grounds, which appears to be covered adequately by fair-use exceptions.
 
Disabled Account
Joined 2012
You never know -- a guy tried to mess with a Hindu shrine on the corner of a busy street and large hotel in Bangkok (a Buddist area) ..... he was beaten to death by the bystanders. None went to jail, there. And, this IS the Internet for all types, everywhere to see.

I know it isnt popular to be respectful of one another on this forum/site.... we regularly trash each other. BUT, beware or be aware ... .
 
Even though I know first hand that for instance cab drivers in Mumbai have little shrines with flashing LED's hanging from their mirrors of any number of Hindu gods I will change it because I would have anyway. BTW my Hindi friends at work don't know what the problem is.

Richard - strange things happen in India all the time that we can't relate to. Kevin Cosner was heavily sanctioned for giving a slight kiss to a Bollywood star in public.

BTW - no more religion or politics on this please.
 
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I will change it because I would have anyway. BTW my Hindi friends at work don't know what the problem is.
...
Kevin Cosner was heavily sanctioned for giving a slight kiss to a Bollywood star in public.
I can assure you that there isn't a problem, but it's your choice anyway. BTW, the artwork is really cool - baby-faced Shiva with blue-skin and red hair, with prominent ash marks across the forehead. Probably late 19th or early 20th Travancore or Tanjore artwork, but could have been derived in turn from earlier North Indian or Nepalese art, where they tend to use charcoal or purple to designate the skin tone of Shiva.

It was Richard Gere who gave the friendly kiss in the air, and the recipient had no objections. However, there were a usual bunch of trouble-making 3rd-parties that filed a complaint of public nuisance, and an idiot magistrate who took cognisance of the complaint. Just bad luck for Richard Gere, who is apparently an ardent Buddhist...

* end of politics *
 
What! you don't like my stack system?
I rate that stacking as particularly uninspired, especially compared to the originality in the discrete opamps presented in this thread. Unfortunately I don't have a photo showing how I used to stack a microwave power meter, frequency counter, spectrum analyzer, and sweep generator in the superstructure of a satellite earth station antenna.

By the way . . . what is the test equipment list (Mfgr/model #)?

Dale

p.s. - I see generally how the SW-OPA works but even with Scott's "Circuit Description" document, and several hours of poking around with LTSpice, I can't work out a real analysis of the VAS and output stages.
 
...I spent two weeks in India on my own coin with Habitat for Humanity building a lot of homes in Lanavla...

Way cool, and hats off to you and Jimmy Carter and his wife, who did something similar a few years ago, even at his age.

But no praise for Brad Pitt, who landed up at the same location with a bunch of papparazzi, was photographed hammering a few nails, had coffee with the Carters, and quickly vanished after that.
 
Way cool, and hats off to you and Jimmy Carter and his wife, who did something similar a few years ago, even at his age.

But no praise for Brad Pitt, who landed up at the same location with a bunch of papparazzi, was photographed hammering a few nails, had coffee with the Carters, and quickly vanished after that.

He did hang around a little, his bodyguards were more hostile than Jimmy's secret service agents. The security for Mr. Carter in general was amazingly invisible but when needed they were very obvious.
 
Scott what is that multi-input pod on your testbench? . . .
Read about the Digilent "Analog Discovery Design Kit" at :

and:

It has received passing mention a few times on this Forum; e.g. Post #2022 in this thread. It certainly looks like a useful tool - though if I had the money for it, I'd have to first decide whether it was a supplement, or a replacement, or a duplication, of my Tek TDS1002.

Dale