Chris,
whatever the cause of the failure was, your fault or defective modules, you should have tried to solve the issue PRIVATELY with Lars first, before publishing information that may damage his image before starting to sell the product. It is only a question of politeness.
I am also a bit surprised about why Lars had chosen Chris for this "public evaluation", given his past published opinions...
Do what you want, it's your problem, but I DO think that you owe some apologies to Lars. PUBLIC apologies, as public as your complains.
Sorry, that's just an opinion, this time I have been unable to close my mouth
whatever the cause of the failure was, your fault or defective modules, you should have tried to solve the issue PRIVATELY with Lars first, before publishing information that may damage his image before starting to sell the product. It is only a question of politeness.
I am also a bit surprised about why Lars had chosen Chris for this "public evaluation", given his past published opinions...
Do what you want, it's your problem, but I DO think that you owe some apologies to Lars. PUBLIC apologies, as public as your complains.
Sorry, that's just an opinion, this time I have been unable to close my mouth
classd4sure said:
Well, then we should look forward to what you call "testing". Pardon the terminology, but "testing" makes it sound more proffessional than "review".😀
classd4sure said:
Even adding snake oil is a tweak. 😀
Hi cdl,
Some aspects are the dark side. Once you hear it for yourself for instance, more now than later too , because you're reliant on the word of the few who've heard it, instead of the many later. Then there's robustness, reliability, fault protection, emi, safety..all that fun stuff. A big part of all that is proper implementation from start to finish, which if you get right, you're a little less in the dark.
That's the definition of integrating components like class d module based amps, rather than plug and pray..
Some aspects are the dark side. Once you hear it for yourself for instance, more now than later too , because you're reliant on the word of the few who've heard it, instead of the many later. Then there's robustness, reliability, fault protection, emi, safety..all that fun stuff. A big part of all that is proper implementation from start to finish, which if you get right, you're a little less in the dark.
That's the definition of integrating components like class d module based amps, rather than plug and pray..
BWRX said:
classd4sure said:
Sorry, I didn't mean for it to come across like. I simply meant to convey that you are rather familiar with the UcD modules and have posted very positive listening impressions before.
On the topic of fixing pre built modules - I still have to fix a UcD180 I damaged, and reworking that probably won't be any easier than something like Lars' NCD modules. They also use a 4 layer board and might use lead free solder as well.
BWRX said:
Not a problem at all I realize exactly how you intended it, but others who don't may have gotten the opposite impression.
The 180 modules are just a 2 layer board, changing mosfets was it? Only the daughter card is 4 layer I think, until the 700 modules.
I agree about reworking them it takes a skilled hand either way.
classd4sure said:
Just wanted to make sure 🙂
So the main boards are only two layers, eh? I just assumed they were 4 without really looking. I removed the mosfets no problem (2 layers with none of the pads connected to the ground plane makes that easier) but still have to make sure all the driver parts are ok. Time is my only enemy.
Good luck with the NCD repairs.
I have DIY amps with 4-layer boards, allthough now sounding wonderfull, they were at fault and there had to be external connections made with simple wire - even if it is tested ok, some day it might fail somewhere - I wont touch 4-layer boards again, ever
soongsc said:
I just revisited the NCD site, and it has some explanation on the connections. Interesting enough that it seems the NCD can be used in either inverting or non-inverting mode if they are connected single ended. This is very convenient for recordings that somehow get inverted in absolute polarity.
That brings to rise an interesting question. Exactly what is the absolute polarity of an AC signal.
I've got the inputs balanced with the outputs of one module inverted to the speaker, but so are also inverted to it. That's for better loading of the supply high demand.
All that maters in terms of absolute polarity is that the speakers aren't driven out of phase with one another, so they work in unison, less the channel seperation /stereo musical perspective.
I've got the inputs balanced with the outputs of one module inverted to the speaker, but so are also inverted to it. That's for better loading of the supply high demand.
All that maters in terms of absolute polarity is that the speakers aren't driven out of phase with one another, so they work in unison, less the channel seperation /stereo musical perspective.
IMO, absolute polarity of an AC signal -absolutely not matter. 
Chris, seems, you always here. Do you sleeping sometimes, you're robot? 🙂 Don't worry about "New Module by Lars Clausen", just have a rest.
Chris, seems, you always here. Do you sleeping sometimes, you're robot? 🙂 Don't worry about "New Module by Lars Clausen", just have a rest.
Pierre said:Chris,
whatever the cause of the failure was, your fault or defective modules, you should have tried to solve the issue PRIVATELY with Lars first, before publishing information that may damage his image before starting to sell the product. It is only a question of politeness.
I am also a bit surprised about why Lars had chosen Chris for this "public evaluation", given his past published opinions...
Do what you want, it's your problem, but I DO think that you owe some apologies to Lars. PUBLIC apologies, as public as your complains.
Sorry, that's just an opinion, this time I have been unable to close my mouth
Pierre, such a romantic. Had it been something I'd done or even if it still turns out to be I'll let you know I don't think it ruins my image. If by image you mean marketing I'm not your salesman. It seems to me you are asking me to apologies to you for telling you the truth as it occurs. If you can't face the world mon ami, the world ***** you.
As far as Lars' image based on his character, skill, possible reputation, sanity or religious beliefs... there's been nothing but good said. Even with the amps in their current state, I don't feel the need to apologies to you for that either.
Oh, pleeease, Chris... why the hell should I ask you to apologize to ME? If you had to apologize, it should be done to Lars, although he is elegantly keeping apart from this polemics.
You are so.... controversial, and I am too tired...
You are so.... controversial, and I am too tired...
classd4sure said:
Main thing is your speakers are ok! 20v DC wouldn't be too healthy😱
Seems very strange the op-amp has 3vdc again😕 are you going to try replacing them with something else just to see if they are the problem? I guess the modules you have use the LM6172's the same as the picture on the NCD site picture
I also cannot see anything that would damage Lars image, its not really that rare for evaluation modules to have a few bugs, I'm sure Lars will have these things ironed out for the final production units
Anyway come on chaps, lets not have pages of arguments🙄 lets at least try and give Chris some help/ideas to get these things up and running!
Chris: Did the same fault occur on the two separate modules at the same instant?
Did you check the power supplies? (since they are common to both modules).
Could there be any (significant) DC component on the input wires (since they are probably also common to the two modules.)
That was also exactly the intention, and i had the unit playing here for a week or so, all day long, Chris should only change the mains voltage from 230 to 115V, and then listen.
However - sadly a capacitor was doa, and now i guess most of the amplifier is something different.
About the fault. It would be obvious to assume there is a pattern, and maybe the regulator was what killed the capacitor first, and now someting else on two modules, maybe in a situation where one supply came on before the others or something like that.
However both modules have been thoroughly tested with only +, then only - then only + and - and without GND. And absolutely nothing happened except the module played happily again after connecting all supplies. I will take a real close look tomorrow morning at the data presented here in the tread, to see if it can lead to .. anything.
Thanks
Did you check the power supplies? (since they are common to both modules).
Could there be any (significant) DC component on the input wires (since they are probably also common to the two modules.)
That was also exactly the intention, and i had the unit playing here for a week or so, all day long, Chris should only change the mains voltage from 230 to 115V, and then listen.
However - sadly a capacitor was doa, and now i guess most of the amplifier is something different.
About the fault. It would be obvious to assume there is a pattern, and maybe the regulator was what killed the capacitor first, and now someting else on two modules, maybe in a situation where one supply came on before the others or something like that.
However both modules have been thoroughly tested with only +, then only - then only + and - and without GND. And absolutely nothing happened except the module played happily again after connecting all supplies. I will take a real close look tomorrow morning at the data presented here in the tread, to see if it can lead to .. anything.
Thanks
Hi Lars,
One module has survived and I've located the problem with the other. Thermal stress caused a solder joint to break, which I repaired, now it has 120hz hum as with a blown output stage, but, but shuts off with .003Vdc on the output two seconds after plugging it in.
Both modules act as before with or without load in terms of powering on and the cycle of flashes, which is that one doesn't enable the output stage without a load attached but the other will. Lars say's this is normal...
Based on the solder joint that failed in question, that of the filter coil because only the very end of the wire was in contact with the joint (imagine that rectifying with a blown output), I'll now direct my focus towards the output stage, drivers and such.
...tomorrow.
One module has survived and I've located the problem with the other. Thermal stress caused a solder joint to break, which I repaired, now it has 120hz hum as with a blown output stage, but, but shuts off with .003Vdc on the output two seconds after plugging it in.
Both modules act as before with or without load in terms of powering on and the cycle of flashes, which is that one doesn't enable the output stage without a load attached but the other will. Lars say's this is normal...
Based on the solder joint that failed in question, that of the filter coil because only the very end of the wire was in contact with the joint (imagine that rectifying with a blown output), I'll now direct my focus towards the output stage, drivers and such.
...tomorrow.
classd4sure said:
Absolute cannot be heard on systems that need upgrading. Especially upgrading of speakers. If you only like listening to sign waves, well of course it doen't matter.
😉
soongsc said:
So then I guess you're ears and speakers are also privy to the high frequency square wave that the polarity of your audio signal is derived by.
Absolute phase - it does matter, but most people wont notice if it is or not
Problem is that difference is so subtle that you can only tell the difference if you have a remote control, and only if your speaker are really good, and in that case its only very good when in absolute phase
Problem is that difference is so subtle that you can only tell the difference if you have a remote control, and only if your speaker are really good, and in that case its only very good when in absolute phase
- Status
- Not open for further replies.