http://www.newclassd.com/
I'm looking forward to testing this module. Lars intended it to be a new level of high end class d.
You can look forward to my experiences with it as I plan on sharing them on the forum.
Lars Clausen is responsible for this module, and I'd like to stress that it is independant of LCaudio.
Regards,
Chris
I'm looking forward to testing this module. Lars intended it to be a new level of high end class d.
You can look forward to my experiences with it as I plan on sharing them on the forum.
Lars Clausen is responsible for this module, and I'd like to stress that it is independant of LCaudio.
Regards,
Chris
Member
Joined 2003
The distortion graphs only show for power output up to 100W@8ohms and only show up to 10kHz. However, the amp is advertised as being able to deliver 400Wrms@4ohms, and 650Wrms@2ohms. I would be interested in seeing the distortion graphs at the rated power output, and I would like to see frequency response to 20kHz, not 10kHz. At this point it looks like LCAudio is trying to hide something when they advertise high power and high bandwidth (120kHz) capabilities, but don't show any measurements under these conditions to show how the performance actually is.
I look forward to your results.
I look forward to your results.
Did any of you get any clear answer to:
-Is the same output filter being used at all different switching frequencies?
-What is the standard switching frequency?
-Is the 120kHz bandwidth achievable at all switching frequencies?
-Under what conditions does it perform 120kHz? (power, harmonic distortion, phase distortion, noise...)
-Is the same output filter being used at all different switching frequencies?
-What is the standard switching frequency?
-Is the 120kHz bandwidth achievable at all switching frequencies?
-Under what conditions does it perform 120kHz? (power, harmonic distortion, phase distortion, noise...)
I think at heavier loads the switching frequency drops and at light loads it's highest.
I think the given graphs demonstrate the advantage of this by showing it''s level of "lowest distortion for certain conditions" which is also presumed to be for example 10W at 4 ohms, which I think even with speakers of 102db efficiency I use alot more than 10watts on average.
Aside from that I do think it would be important to see how it fairs across its full rated frequency and power response for various rated loads.
I think the given graphs demonstrate the advantage of this by showing it''s level of "lowest distortion for certain conditions" which is also presumed to be for example 10W at 4 ohms, which I think even with speakers of 102db efficiency I use alot more than 10watts on average.
Aside from that I do think it would be important to see how it fairs across its full rated frequency and power response for various rated loads.
Sorry guy, I did the same 3 months ago for a multichannel amplifier...Mine is rated at 200W into 8 ohms and 350W at 4 ohms. Variable dead time, so that's mean low dead time at lo power and higher at higher power...Only thing, I dont have micro-processor to watch reliability...But never blow any module as for now. I will sell lot of these module soon, I have over stock...The pic is prototype with fews production module, unfortunately I did not have complete module on hand, all sold!
Fredos
www.d-amp.com
Fredos
www.d-amp.com
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This looks great!
I have to admit, I got a little teary eyed when I say the "Quality Policy" - I wish every company do the same. And I know without a doubt that Lars will stand by this policy.
The risc controller looks very interesting.
And SMPS would always be welcomed for those of us who look for pro-sound solutions. 🙂
I can hardly wait for Chris' reviews.
I have to admit, I got a little teary eyed when I say the "Quality Policy" - I wish every company do the same. And I know without a doubt that Lars will stand by this policy.
The risc controller looks very interesting.
And SMPS would always be welcomed for those of us who look for pro-sound solutions. 🙂
I can hardly wait for Chris' reviews.
Looks nice.
DcibeL said:
What does LC Audio have to do with this? This is a Lars Clausen product from NewClassD, which is a subsidiary to Dexa Technologies, and thus has nothing to do with LC Audio.
Lars,
If you're reading this, I'll take one off your hands for some in-depth testing, much like I did with the NuForce amplifiers, if you're up for the challenge that is.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
If you're reading this, I'll take one off your hands for some in-depth testing, much like I did with the NuForce amplifiers, if you're up for the challenge that is.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
Thank You for all your questions, and remarks!
UrSv: Exactly, this has nothing at all to do with LCAudio, and also the technology is not the same as theirs.
IVX: You are right, this prototype is hand soldered. When i get the production modules in, i will of course post some new pictures. 🙂 Sorry about that.
Snickers Is: Yes, the same output filter is used for all sw freq's as the module is readjustable. Std sw freq is 450 kHz (adjusted to freq counter).
The audio bandwidth is not so much limited by sw freq, as by load impedance. BTW the 120 kHz bandwidth only applies to the 'local feedback' setting, not the 'global feedback'. You can use my module up to 1 MHz sw freq, but it's a tradeoff between high sw freq and low sw noise. So higher sw freq gives also higher noise.
In this module the optimum performance kicks in at 450 kHz.
I must admit i have not attempted to measure THD at 120 kHz, as the products would be in range of 240, 360 kHz etc. Hardly audible. However could be a fun experiment with a spectrum analyzer.
Dcibel: Thank You for your suggestion. But in my setup the THD reading in the area 10 - 20 kHz seem to fall off due to the AES17 'brickwall' filter before the A/D converter. So the result isn't really useful.
Fredo: Congratulations on your new amplifier. Looks cool 🙂
Since i saw that chinese guy selling his modules for only 28 Yuan / 7$ for the same power, i decided not to try and compete on price. Instead i think there is a place for something where the goal is not so much high sales figures, but instead small quantities of high quality modules, where a lot of effort is put into getting just a little bit better performance.
Of course this cost a little more. But after all, the modules don't account for a very high percentage of the cost of the total amplifier. But they do account for a very big part of the sound quality.
Thank You all for your questions, keep'em coming.
Lars
UrSv: Exactly, this has nothing at all to do with LCAudio, and also the technology is not the same as theirs.
IVX: You are right, this prototype is hand soldered. When i get the production modules in, i will of course post some new pictures. 🙂 Sorry about that.
Snickers Is: Yes, the same output filter is used for all sw freq's as the module is readjustable. Std sw freq is 450 kHz (adjusted to freq counter).
The audio bandwidth is not so much limited by sw freq, as by load impedance. BTW the 120 kHz bandwidth only applies to the 'local feedback' setting, not the 'global feedback'. You can use my module up to 1 MHz sw freq, but it's a tradeoff between high sw freq and low sw noise. So higher sw freq gives also higher noise.
In this module the optimum performance kicks in at 450 kHz.
I must admit i have not attempted to measure THD at 120 kHz, as the products would be in range of 240, 360 kHz etc. Hardly audible. However could be a fun experiment with a spectrum analyzer.
Dcibel: Thank You for your suggestion. But in my setup the THD reading in the area 10 - 20 kHz seem to fall off due to the AES17 'brickwall' filter before the A/D converter. So the result isn't really useful.
Fredo: Congratulations on your new amplifier. Looks cool 🙂
Since i saw that chinese guy selling his modules for only 28 Yuan / 7$ for the same power, i decided not to try and compete on price. Instead i think there is a place for something where the goal is not so much high sales figures, but instead small quantities of high quality modules, where a lot of effort is put into getting just a little bit better performance.
Of course this cost a little more. But after all, the modules don't account for a very high percentage of the cost of the total amplifier. But they do account for a very big part of the sound quality.
Thank You all for your questions, keep'em coming.
Lars
Sander: Of course, i would appreciate that!
But i'm not going to release anything until it's tested to the core, and the documentation is 100% ready. And as you can see i'm not quite there yet 😉
When i am, then let's talk again 🙂
All the best from
Lars
But i'm not going to release anything until it's tested to the core, and the documentation is 100% ready. And as you can see i'm not quite there yet 😉
When i am, then let's talk again 🙂
All the best from
Lars
Thanks Lars,
Excellent! Good luck with the testing and all, let's keep in touch.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
Excellent! Good luck with the testing and all, let's keep in touch.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
The measurements look good so far. Congrats !
Someone mentioned that he'd be interested in THD measurements at full power (or almost full power). IMO these are not THAT important. For a HiFi amp THD at 1 Watt and 0.1 Watt would be far more interesting.
Regards
Charles
Someone mentioned that he'd be interested in THD measurements at full power (or almost full power). IMO these are not THAT important. For a HiFi amp THD at 1 Watt and 0.1 Watt would be far more interesting.
Regards
Charles
BTW, what about phase lead RC in the "post filter mode" in respect to UcD patent?
PS: Hand soldered proto it's ok, just not so looks nice yet.
PS: Hand soldered proto it's ok, just not so looks nice yet.
peranders said:
Off topic: Absolutely.
Charles, if 1W more interesting, why not use tda8939 ($3) which outperform Pb-free_proto at THD 3 times if runs at 20W even? Just try it. 🙂
IVX: Thank You for bringing this nice little chip into scope. But according to Philips's own datasheet:
http://www.semiconductors.philips.com/acrobat_download/literature/9397/75013749.pdf
The THD is not 3 times lower than 0.001% (0.0003%) but rather 0.05%. This is 50 times MORE distortion.... ??
THD here shown in a reference design from Cirrus Logic:
http://www.semiconductors.philips.com/acrobat_download/literature/9397/75013749.pdf
The THD is not 3 times lower than 0.001% (0.0003%) but rather 0.05%. This is 50 times MORE distortion.... ??
THD here shown in a reference design from Cirrus Logic:
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