Lumba Ogir said:
Lumba,
After returning from abroad (Paris, Amsterdam, etc...) and reading your :bs: in the YAP thread http://www.diyaudio.com/forums/showthread.php?postid=1634532#post1634532 and finally this one, I have decided it makes definitely no sense to argue with your positions, simply because one should never try to teach a pig to sing; it wastes your time and it annoys the pig. (@ Robert Heinlein).
Overall, I have barely ever seen such a pile of unsubstatiated statements. While trying to replace hard facts with your own idiosyncrasies, you don't even seem to bother to invoke the usual GEB arguments. Have you ever listened to a AD797 and decided it's not good for your superior ears? Have you ever studied the AD797 topology, queried Scott about, and then decided is mediocre? Or you just know? What makes you think you are qualified to evaluate other people designs and results?
Lumba Ogir said:
If you read the first post, you'd understand I did this amp for fun just to compare a discrete to a monolithic amp. It's not a step forward nor a step backwards. It's a sidestep. You know I'm not a fan of monolithic opamps, but AD797 is an exception.
Show me a design (and not a ridiculous complex one) that will sound significantly better than this one.
Lumba Ogir said:
In your extremely humble opinion, presumably?
😉
Well, it's nice to have someone here who knows "how it is" to tell us all. 😀
I've simmed the simplified data sheet schematic of the AD797 and commented on a few features of the circuit's opperation that I believe the sim illuminates - without claiming any high degree of precision/fidelity to the real chip
still maybe the sim could be helpful:
http://www.diyaudio.com/forums/showthread.php?postid=1525757#post1525757
http://www.diyaudio.com/forums/showthread.php?postid=1556808#post1556808
still maybe the sim could be helpful:
http://www.diyaudio.com/forums/showthread.php?postid=1525757#post1525757
http://www.diyaudio.com/forums/showthread.php?postid=1556808#post1556808
syn08,
Nelson,
Patrik,
No, I don`t use OpAmps, they are put on blacklist together with some other parts.
I`m sorry we don`t fully agree on everything, everyone should follow his own convictions to achieve the desired results.
Nelson,
OK, if you say so.
I did that twice, didn`t I, you hesitated. It´s bad...for you. Things should not be made simpler than necessary, especially if you are fastidious.
Patrik,
Not just in mine, in Nelson`s as well.
Lumba Ogir said:
So, you know 😀 Well, you need a little more than this Torquemado approach... Show your results, face other people experience, do a fair and controllable comparison and then you may be qualified to judge other people work.
No, to obtain the desired results you do not have to follow your own convictions, you have to follow the Truth. Your statement is the key to the subjectivist team; it's not the Truth that matters, it's the personal, subjective convictions. Otherwise errare humanum est, perseverare diabolicum.
syn08,
look, I am not trying to influence you, please just follow the truthful doctrine you believe in. To avoid unpleasing comments, private correspondence is an option.
look, I am not trying to influence you, please just follow the truthful doctrine you believe in. To avoid unpleasing comments, private correspondence is an option.
Lumba Ogir said:
Neither am I. I can't hope you'll give up your religious beliefs.
Over and out.
I keep reading how hard it is to get the AD797 working OK, yet it sounds very good in my Quad 405-2 (modded), with just 100µF decent electrolytics (two, to ground) and 100nF ceramic (two, to ground) decoupling. I also added the 50nF distortion cancellation cap directly on the legs of the OpA package.
Can it sound good even if oscillating like mad behind the scene (of my 100MHz 'scope)?
Can it sound good even if oscillating like mad behind the scene (of my 100MHz 'scope)?
Patrik Floding said:
No, you are probably fine. AD797 is not very difficult to handle if good layout principles are employed. To figure out what "difficult" means, you should try something like the OPA847 or AD8056...
syn08 said:
Thanks for the reply!
Layout isn't great, but at least the decoupling is right at the OpA.
The advantage of super-shunt regulators is that, if you organize the circuit correctly, the ground return currents are constant. You can see immediately that it there will be a reduction in noise injection between the different circuit s both into the power rail, and into the signal lines (here, because there is always a finite ground return resistance, so Is*Rgnd + Vsig is avoided).
For this to work effectively, th e variuos stages in th e circuit need to be partitioned carefully and local tight loop super shunt regulation applied to these individual stages.
I think if you apply super shunt regulation without partitioning correctly, you will not get the full benefit.
For this to work effectively, th e variuos stages in th e circuit need to be partitioned carefully and local tight loop super shunt regulation applied to these individual stages.
I think if you apply super shunt regulation without partitioning correctly, you will not get the full benefit.
Line-up, not neccessarily so. If the supply voltage changes, the current through the ground return will change as well. If the shunt is fed from a current source, the ground return current is fixed.
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