Thanks guys for keeping me warm, love you all you do really tickle my funny bone. You cant learn anything unless your mind is fluid. We should have some beer sometime in a middle place. Nice design Ostripper. To be honest were all here to build it so lets get on with it, lets get intimate with it and see whether its our type.😎
The hifi standards for slew rate are between 5V/us-15V/us for 50 volt rails and 10V/us-30V/us for 100volt rails depending on application and topology, that's why the LM3886 is so proud of its slew rate. While high slew rates like 300V/us might promise mirror like sound reproduction and be useful for high excursion subwoofers and public address subwoofers a lot of things can go wrong and when they do go wrong your ears get to know about it. Luckily with subwoofers these things can get masked as our ears are dull in this domain. What's Dan Dagostino amplifiers slew rate or Pathos. Why would a high end amplifier be proud of 5V/us? Some specs in audio are just chatter
H
HAYK
On the first post there is a gain/phase response that shows about 65db at 20khz, the OP doesn't say what is it, bellow it is the open loop gain of LM3886 which is only 50db to suppose for comparison. The LM3886 with closed loop gain of 26db, it remains only 24dB NFB for correction. With this amp, the closed loop gain is 30db this results an NFB of 35db only. This Amp could be qualified as studio grade if the gain/phase curve is that of closed loop or the NFB 65db at 20khz.
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I wonder: if the amplifier designed by @OnAudio is a good amplifier, and I've no reason at all to doubt it, then why @jan.didden mocks him?
Fair enough.
First, anybody can throw up an LTspice schematic, they're all over the 'net.
If you read his prose, he's either saying nothing of substance, or he's missing the mark.
For example, his babble about subwoofer slew rate shows he has no clue what he's on about.
There are many members here that are not experienced enough to know the difference between genuine good advice and knowledge on the one hand,
or just some idiot who doesn't know what he's talking about on the other hand.
I think it is our responsibility to give good advice, and when we are not sure, don't.
There are other members that just want to see their stuff on a screen, the hell what BS they peddle.
It's dishonest and irresponsible, a disgrace to our hobby and this forum and disrespectful to the other members here.
If I see any, I call them out.
This guy hits all the big red lights.
If you have no reason to doubt, maybe you can take another look?
I will bow out now.
Jan
First, anybody can throw up an LTspice schematic, they're all over the 'net.
If you read his prose, he's either saying nothing of substance, or he's missing the mark.
For example, his babble about subwoofer slew rate shows he has no clue what he's on about.
There are many members here that are not experienced enough to know the difference between genuine good advice and knowledge on the one hand,
or just some idiot who doesn't know what he's talking about on the other hand.
I think it is our responsibility to give good advice, and when we are not sure, don't.
There are other members that just want to see their stuff on a screen, the hell what BS they peddle.
It's dishonest and irresponsible, a disgrace to our hobby and this forum and disrespectful to the other members here.
If I see any, I call them out.
This guy hits all the big red lights.
If you have no reason to doubt, maybe you can take another look?
I will bow out now.
Jan
The JBL LSR28P studio monitor used the LM3886 to drive the tweeter. It was used to make THX certified systems. This speaker was used by many recording studios around the world to monitor and master many of the recordings we all listen to for many years. So yeah, I would say it is qualified as 'studio grade". Maybe the OP could build his amp design, test it and share the results.
A studio grade amp has low distortion, low noise, flat frequency response, recovers from clipping quickly, and most importantly can run all day for days on end at full power without failing. Failure is not an option in a studio! If anything fails you are not making money until it is fixed. That is often the deciding factor.
Thanks Jan for getting that off your chest and for coming out clean. Now we can get on with the build.
Thank you for your appreciated reply, but please note that I did not wonder what your technical mission is, I was wondering why you mock him.
In other words I was wondering why your behavior is not from a technical point of view, but from a human point of view.
Fair point. But did I?
When I say that someone doesn't have a clue about something, that is a factual statement (if I am right; of course if I am wrong, the statement is wrong).
But it's not mocking, is it? I even gave an example showing why he appeared clueless.
Or are you referring to another statement?
Jan
When I say that someone doesn't have a clue about something, that is a factual statement (if I am right; of course if I am wrong, the statement is wrong).
But it's not mocking, is it? I even gave an example showing why he appeared clueless.
Or are you referring to another statement?
Jan
Once Jan and his team stop feeling threatened they will come around. I haven't even offered a silent switcher alternative😎. There are many business and personal interests here as in any other forum.
English is my first and only language. My reading of Jan’s comments don’t come over as a personal attack. He points out that the complete failure to understand slew rate for an amplifier designer is grossly incompetent. Both the Douglas Self and Bob Cordell books cover slew rate in detail. Once the slew rate is adequate there is no benefit in making it higher. Further, woofer amps by their nature have by far the least demanding slew rate requirements since despite high power outputs, the rate of change of the signal is very low as Jan demonstrated. If Jan was to critique one of my designs, I would be most grateful and would take his comments on board.
I have no designs to contribute at this time, but if and when I do I would be delighted to hear from the many competent folks like Jan whose valuable and measured contributions make this forum so great.
Anyway, let’s get back to discussing the design. I think we can agree that the slew rate is at least adequate!
I have no designs to contribute at this time, but if and when I do I would be delighted to hear from the many competent folks like Jan whose valuable and measured contributions make this forum so great.
Anyway, let’s get back to discussing the design. I think we can agree that the slew rate is at least adequate!