SSassen said:
In fact there are very good technical reasons to use pre-filter feedback. However you might have noticed that my modules allow a free choice of pre or post feedback.
So i don't understand why you say i am 'dead set against post-filter feedback'.
Right, sorry, it was early in the morning here
😀
Voltage noise or fluctuations might be better words. I think you got the meaning allright.....
You can just once look at the pic http://www.newclassd.com/images/ncd3.jpg, and have the schematic taken instantly. Hint: left upper corner, two pots to the two bc856+NPO cap, 1g86 (1 gate XOR), l6385, zumt718/618 (thx you Bruno one more time 🙂 )next said:
IVX: You are quite perceptive 
btw Bruno is not using any of these, you want to thank him for, is he?? (I will let you answer that one yourself). 🙂
next: Take the term 'seismic sensor' as an analogy for the way the sensor works. It has nothing to do with actual seismic (earthquake) activity.
The nano alignment is done using the trimmers and a dual trace storage scope (and yes it does have < 1nS resolution).
Lighten up please 😉
btw Bruno is not using any of these, you want to thank him for, is he?? (I will let you answer that one yourself). 🙂next: Take the term 'seismic sensor' as an analogy for the way the sensor works. It has nothing to do with actual seismic (earthquake) activity.
The nano alignment is done using the trimmers and a dual trace storage scope (and yes it does have < 1nS resolution).
Lighten up please 😉
Lars Clausen said:IVX: You are quite perceptive
Not so much perceptive, just i has built such "nano alignment" in the 1999 for my very first sub class D amp. Subwo1, ssanmor, and many others diyaudio.com members also built it (2110+diodes) before you, but we are didn't know that it's so new and so cool. 🙂
Needless challenging and personal stuff is now in Texas.
I tried to remove as less valuable content as possible.
/Hugo
I tried to remove as less valuable content as possible.
/Hugo
IVX: Very interesting...! Is any of these socalled nano alignment amps published here on the forum? Or anywhere else. I am curious if it's the same thing we are talking about.
Yep, sure enough. You are right! It's basicly the same thing, that i call nano alignment. Allthough i have not implemented it in exactly the same way, it's close enough. The rest of the amplifier has of course no resemblence with NewClassD, but that's another story.
Thanks for bringing this schematic to my attention. 🙂
Thanks for bringing this schematic to my attention. 🙂
Hope that alignment is rock steady. We never dared to get that close in saftey critical applications in the early 90s.
It is rock steady. And should the user somehow tinker with the trimmers, so the amplifier goes in shoot-through mode, the safety system will 99% sure shut the amplifier down. But this is an abnormal condition, as we advise users against re-adjusting the nano alignments.
Just curious: Which one of them are you assuming is a DC trimmer, and from where did you get that 🙂
Well, from the plethora of trimmers I guess he just picked one? Just close your eyes and point Chris, that's it, and then simply turn it fully clockwise and back, do try to keep a beat as you see your woofer cones move back and forth 🙂 They don't? Guess you got the wrong trimmer then, next ...
Best regards,
Sander Sassen
Electromigration isn't your friend
Yes well... it IS a shame I should have to guess... 🙄
Let's see .... two are for "nano alignment" (snicker)....
I guess the third is either a DC trim pot or ... so thaaaat's what a seismic sensor looks like 😀
Let's see .... two are for "nano alignment" (snicker)....
I guess the third is either a DC trim pot or ... so thaaaat's what a seismic sensor looks like 😀
The other alternative is that there's no DC trim but that final pot is in fact an independant frequency adjustment.... set to 450khz good for up to 1Mhz? They run hot at 450k though!
I was just thinking, since these modules have 'nano-alignment' why do we need trimmers? If Lars can pull off a control-loop which can regulate timing within 1ns I guess regulating all other parameters automagically should be a walk in the park?
Oh wait, we still don't know what nano-alignment does exactly. From where I'm sitting Lars could be referring to the wafer stepper that aligns the wafer in the lithograph so the driver ICs that they're making that feature on Lars' amplifier align with it properly, or rather, with nanometer accuracy.
Best regards,
Sander Sassen
Na, no? Nonsense?
Oh wait, we still don't know what nano-alignment does exactly. From where I'm sitting Lars could be referring to the wafer stepper that aligns the wafer in the lithograph so the driver ICs that they're making that feature on Lars' amplifier align with it properly, or rather, with nanometer accuracy.
Best regards,
Sander Sassen
Na, no? Nonsense?
Would it also regulate stuff that you didn't know needed regulation, or am I stretching it a bit too much now? I'm pretty sure there could be something in desperate need of ultra tight regulation at a certain circuitpart thingy in my current project.SSassen said:
Damn, me wants some of that 😎
Sander, please... You're not funny anymore.
As far as the nano alignment goes, Lars has just explained its basics, and IVX even provided links and schematics to explain it further. And wouldn't you prefer to be able to tune the little nanos with a pot, rather than hoping the resistors you ordered are matched beyond spec? We're not talking advanced computer control here.
classd4sure: Not that I know anything about this, but it seems pretty likely that the third pot is for switching frequency. The homepage says it's easily adjustable, which suggests a simple pot, and if I've understood Lars correctly, the two others are for the nano alignment.
Lars: Is there any good reason why the frequency is adjustable over such a wide range, when you recommend keeping it at stock frequency?
As far as the nano alignment goes, Lars has just explained its basics, and IVX even provided links and schematics to explain it further. And wouldn't you prefer to be able to tune the little nanos with a pot, rather than hoping the resistors you ordered are matched beyond spec? We're not talking advanced computer control here.
classd4sure: Not that I know anything about this, but it seems pretty likely that the third pot is for switching frequency. The homepage says it's easily adjustable, which suggests a simple pot, and if I've understood Lars correctly, the two others are for the nano alignment.
Lars: Is there any good reason why the frequency is adjustable over such a wide range, when you recommend keeping it at stock frequency?
You? Turning the pot? Without any means of verifiying whether you make things worse or better? That's not a feature, that's a shortcoming. All trimmers drift over time and with temperature, so even if they're set properly at the factory, they could be off after a few months of use. I'm a firm believer in auto-setting features, either by smart design or a microcontroller. If Lars implemented that with the risc controller I'd nod in approval, but he hasn't as he mentioned before, the controller just monitors the amp's behaviour to avoid mishaps in case of component failure or user error.
Best regards,
Sander Sassen
User error has a 99% success rate
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