The thread "New module by Lars Clausen" has been closed by the moderator.
I think that is a pity, since it not until now that the modules are being shipped out and we have a fair chanche to take part of more than one persons point of view.Also it might be interesting to have it compared to other class d amps, old as well as new ones.
If there are more people interested in this issue I hope someone will start a thread or hang on to this one.
With all due respect:
Anzgar
I think that is a pity, since it not until now that the modules are being shipped out and we have a fair chanche to take part of more than one persons point of view.Also it might be interesting to have it compared to other class d amps, old as well as new ones.
If there are more people interested in this issue I hope someone will start a thread or hang on to this one.
With all due respect:
Anzgar
I've started a thread here for comparison of class Ds and linear amps.
http://www.diyaudio.com/forums/showthread.php?s=&postid=1021702#post1021702
Seems like a friendly discussion up to now.
http://www.diyaudio.com/forums/showthread.php?s=&postid=1021702#post1021702
Seems like a friendly discussion up to now.
Hi, all.
Thank you Anzgar for the thought to start a new thread for the listening impressions of the NewClassD modules.
Let's hope that we can all contribute with unbiased opinions to whatever listening experiences will be gained with this new design by Lars.
I have followed the previous post from day one and although great insight was gained (thanks classd4sure), in the end i was left with a bitter taste in my mouth for the words exchanged between fellow diyiers (of shorts..).
Anyway as i am also waiting for the modules to arrive to Greece, when i finish building the true dual mono power amp, i will revert with my findings against linear amplification (Audia Flight Pre / Power 100 class-A designs) and two different sets of loudspeakers: one of the sensitive kind (Furuyama Audio Labs full range assisted by a Great Heil tweeter and Backes&Muller Sub1) and the other of the low sensitivity kind (Dynaudio Confidence 5 - one of the best for my liking anyway).
Let's hope that we will get many replies on this thread with all sorts of comments on sonics only. I will not be posting any measurments or graphs, just plain comments of how they sound.
I might be tempted to test it against the zappulse 2.3Se and XE700 amps i have also built in the past.
Bye for now,
Nikos.
Thank you Anzgar for the thought to start a new thread for the listening impressions of the NewClassD modules.
Let's hope that we can all contribute with unbiased opinions to whatever listening experiences will be gained with this new design by Lars.
I have followed the previous post from day one and although great insight was gained (thanks classd4sure), in the end i was left with a bitter taste in my mouth for the words exchanged between fellow diyiers (of shorts..).
Anyway as i am also waiting for the modules to arrive to Greece, when i finish building the true dual mono power amp, i will revert with my findings against linear amplification (Audia Flight Pre / Power 100 class-A designs) and two different sets of loudspeakers: one of the sensitive kind (Furuyama Audio Labs full range assisted by a Great Heil tweeter and Backes&Muller Sub1) and the other of the low sensitivity kind (Dynaudio Confidence 5 - one of the best for my liking anyway).
Let's hope that we will get many replies on this thread with all sorts of comments on sonics only. I will not be posting any measurments or graphs, just plain comments of how they sound.
I might be tempted to test it against the zappulse 2.3Se and XE700 amps i have also built in the past.
Bye for now,
Nikos.
Hi marmasuoris and welcome to the thread!
I see you have got your 700XE modules,congratulations!I have not got mne or got my money back either, I got a copuple of faulty modules which I returned and when LC Audio announced they will not deliver any of them I thought I'd get my money back but so far I only payed for nothing.
I obviously will receive the NewClassD modules tomorrow and I can hardly wait until then,,
, I hope I'll won't do any mistake in assembling the amp but spend tomorrow evening listening to the new class D for the first time.
Will you tell a litte about how you experienc the sound of 700XEs?To start with....
I see you have got your 700XE modules,congratulations!I have not got mne or got my money back either, I got a copuple of faulty modules which I returned and when LC Audio announced they will not deliver any of them I thought I'd get my money back but so far I only payed for nothing.
I obviously will receive the NewClassD modules tomorrow and I can hardly wait until then,,
, I hope I'll won't do any mistake in assembling the amp but spend tomorrow evening listening to the new class D for the first time.Will you tell a litte about how you experienc the sound of 700XEs?To start with....
classd4sure said:hmmmmm..... while you're at it, maybe you can compare 700XE to mueta too. That'd be super interesting.
Those are made of unobtanium:
http://www.unobtainium.com/
Anzgar: O.K. then, let's start...
I did not experience any problems so far with these modules and i have implemented two different power amps. The first one was with the stock power supply/transformer as supplied by LC Audio (i.e. Predator extended with 2X15,000mF caps and 550VA single transformer) and the other was a dual mono power supply using two 650VA transformers plus 4X18,000mF Nippon Chemicon Gold Tune caps with 4X35A diodes (normal ones no ultra fast soft recovery ones).
The main difference between the two P/S was a better soundstage, more unconstrained sound better transiets when the stiffer power supply was used. The difference was the same as moving from the zappulse 2.3SE to the 700XE modules. BTW the stiffer power supply can justify the extra expenditure easily and the same applies as well as moving from the 2.3Se modules up to the 700Xe ones. It's a pity though that tey are discontinued but wait...let's be optimistic..let's see how NCD compares....
Soongsc: The Audia power amp is a real beast in the way it was put together: 32 Toshiba IGBTs 2x750 VA trans with a total of 200,000mF Kendeil caps for just 100watts etc. But the end question is how it sounds... Well the 700Xe with the stiffer p/s has better low end, quicker and more robust, the midrange is more clear and the highs more extended but not as holographic as the class A design. Also the microdynamics are better resolved through the class A design but the overall sound is more laid back than with the class-D. If your loudspeakers have high sensitivity and sound up-front and you still want to use the 700XE class-d design then you can combine it with a passive unit (i have used one with a 10k pot) with v.good results.
There was a mismatch when i used the Audia Flight Preamplifier with the 700XE amp and my 95db high sensitivity speakers...there was a high hissing sound that would not go whether i used the single ended or balanced connection. I believe it was the fact that the class-d amp has a higher gain than the matching Audia amp. When the Dynaudios were used the hissing sound diminished a lot but still it was not as dead quite as i have read the UcD amp is (according to classd4sure).
classd4sure: I have not built any other class-d amps except the LC Audio kits (from the first version of zappulse 2.1), but i have heard ready made ones from CI Audio, Tact, Jeff Rowland, Sharp etc. I believe you can tailor the final sound from a diy to your liking and i believe that if you know what you are doing the final result can outperform many ready-made units.
Bye for now,
Nikos
I did not experience any problems so far with these modules and i have implemented two different power amps. The first one was with the stock power supply/transformer as supplied by LC Audio (i.e. Predator extended with 2X15,000mF caps and 550VA single transformer) and the other was a dual mono power supply using two 650VA transformers plus 4X18,000mF Nippon Chemicon Gold Tune caps with 4X35A diodes (normal ones no ultra fast soft recovery ones).
The main difference between the two P/S was a better soundstage, more unconstrained sound better transiets when the stiffer power supply was used. The difference was the same as moving from the zappulse 2.3SE to the 700XE modules. BTW the stiffer power supply can justify the extra expenditure easily and the same applies as well as moving from the 2.3Se modules up to the 700Xe ones. It's a pity though that tey are discontinued but wait...let's be optimistic..let's see how NCD compares....
Soongsc: The Audia power amp is a real beast in the way it was put together: 32 Toshiba IGBTs 2x750 VA trans with a total of 200,000mF Kendeil caps for just 100watts etc. But the end question is how it sounds... Well the 700Xe with the stiffer p/s has better low end, quicker and more robust, the midrange is more clear and the highs more extended but not as holographic as the class A design. Also the microdynamics are better resolved through the class A design but the overall sound is more laid back than with the class-D. If your loudspeakers have high sensitivity and sound up-front and you still want to use the 700XE class-d design then you can combine it with a passive unit (i have used one with a 10k pot) with v.good results.
There was a mismatch when i used the Audia Flight Preamplifier with the 700XE amp and my 95db high sensitivity speakers...there was a high hissing sound that would not go whether i used the single ended or balanced connection. I believe it was the fact that the class-d amp has a higher gain than the matching Audia amp. When the Dynaudios were used the hissing sound diminished a lot but still it was not as dead quite as i have read the UcD amp is (according to classd4sure).
classd4sure: I have not built any other class-d amps except the LC Audio kits (from the first version of zappulse 2.1), but i have heard ready made ones from CI Audio, Tact, Jeff Rowland, Sharp etc. I believe you can tailor the final sound from a diy to your liking and i believe that if you know what you are doing the final result can outperform many ready-made units.
Bye for now,
Nikos
marmatsouris said:
Hi Nikos,
Both my amps share an equally poor layout. That's because the UcD is still on a little test jig, so the modules are right next to each other. You can see a picture of it in my "how to parallel T-networks" thread. There's also alot of spare wiring on the UcD still, because I don't want to cut myself short, so to speak, when I slap them into a case later on.
With them plugged into my 1820M audiodock, and connected to my speakers of 102dB efficiency, the UcD's pick up a hiss audible from about three to four feet away. NCD is painfully audible clear across the room, so that's why I have to turn it up more to bury the noise floor when listening to softer passages. At that volume level the louder passages are thunderous. Perhaps this is due to the higher gain of NCD.
If I unplug the inputs at the audiodock, I can glue my ear next to the tweater with the UcD, and have to strain to hear the very faintest hiss by moving my head around a little. You can call that dead silent I think.
Do the same with NCD, you can easily hear the hiss from a good three feet away, but more disturbing is the much louder beat/heterodyn frequencies which are audible from across the room. You can credit that to a poorly implemented PCB. Lars' former "tip" to cure this if I recall correctly was both to mount the modules as close to each other as possible for the worst possible coupling, and sell you a clock to synch them with. I prefer a better layed out PCB myself, but you can see when you get your modules, Lars already has a synch input on them ready to go.
On speakers of lower efficiency, NCD hiss is still audible from the listening position, but the audio can overtake it at much lower volumes, so it's not as tiring, and if you turn it up a little to compensate for the poor noise floor, the louder passages aren't so shocking. In other words it becomes listenable for longer periods of time.
The 700XE's big thing over the 2.3SE was a much higher idle current, (it runs toasty, doesn't it?). The NCD has this in common, I doubt the two will be very different in sonics or behavior, but I look forward to your results with it.
I agree with you in some small way that you can absolutely tailor the sound of an amp, but only to a certain extent. You can't make up for a poor noise floor brought on by a less than ideal PCB (nuforce for a good example of that). Nor can you easily make the frequency response load independant if that's not an intrinsic feature of the design already, or the THD frequency independant if not already.
The better amp will allow you to tailor the sound to your liking far easier than one which imposes constraints due to a poor design or layout.
Best Regards,
Chris
classd4sure said:
the modules are right next to each other
Excuse me Mr Chris.
Have you tried powering just one module (i.e. with the other without supply) and checked if the hiss through the powered speaker is the same?
I understand that these modules can emitt some disturbs (EMI/RFI, do not know precisely) and they maybe influence each other.
Maybe they are too close each other.
Anyway I would go with the mono solution anytime (i.e. two completely separate boxes).
Thanks and regards,
beppe
I think it's necessary to really see whether the hiss noise is from. With the kind of gain the NCD has (45db) compared with the sensitivity levels of others which normally range could range from 10db to 25db, this could mean the noise is from the source. If two amps have such difference in noise as Chris has mentioned, it sound proportional to the gain difference and thus the noise source could be the sound card. But it could also be otherwise. I can hardly believe noise floor of amps themselves could be that different to the ear. But it does seem the NCD gain is really too high.
That was a very good explanation Niko. I can relate to what you have described. I have also started to look into some Class D amps, but depending on nature of how I get to listen to them, I may not be able to mention specific brands. But up to now, your findings are similar to mine in general. My reference is a Hafler XL280 kit without modifications.
That was a very good explanation Niko. I can relate to what you have described. I have also started to look into some Class D amps, but depending on nature of how I get to listen to them, I may not be able to mention specific brands. But up to now, your findings are similar to mine in general. My reference is a Hafler XL280 kit without modifications.
Hi classd4sure,
You are quite right about the "toasting" effect. Yes the 700XE run much hotter than the previous zappulses and you definetly need a larger heatsink area to cool them down especially if you are using medium sensitivity loudspeakers (86-89 db).
Since my main sourse is the cds (not that i do not like the sound of my lps through my Pierre Lurne deck with a Denon 304 cartridge) my concern with hissing sounds coming from these class-d modules has to do with the upsampling dac i am using (North Star Extremo 24b/192khz) and the "effect" the parasitic RFI/EMI the modules could impose on it or vice versa. Have you had any experience on this and if there is anything the diyier could do to cancel it?
Most manufacturers of class-d designs will say "scnaffer" but i do not believe this is sufficient. O.K. the box of the class-d amp is aluminium and the grounding can come in different sorts (star, floating etc) but has your experience shown that this interference could find its way "through" other channels too??
Best regards,
Nikos
You are quite right about the "toasting" effect. Yes the 700XE run much hotter than the previous zappulses and you definetly need a larger heatsink area to cool them down especially if you are using medium sensitivity loudspeakers (86-89 db).
Since my main sourse is the cds (not that i do not like the sound of my lps through my Pierre Lurne deck with a Denon 304 cartridge) my concern with hissing sounds coming from these class-d modules has to do with the upsampling dac i am using (North Star Extremo 24b/192khz) and the "effect" the parasitic RFI/EMI the modules could impose on it or vice versa. Have you had any experience on this and if there is anything the diyier could do to cancel it?
Most manufacturers of class-d designs will say "scnaffer" but i do not believe this is sufficient. O.K. the box of the class-d amp is aluminium and the grounding can come in different sorts (star, floating etc) but has your experience shown that this interference could find its way "through" other channels too??
Best regards,
Nikos
Hi soongsc,
i am glad you can confirm my findings.
The noise problem (and i believe it is the high gain) is indeed an issue that i believe Lars and other designers should look into.
The XE700 had an 775mv input sensitivity with 31db gain and 17kohm input impedance somewhere along the lines of the rest of the other zappulse modules and that's why you can also put a passive unit as a pre-amplifier.
The Audia power amp has a 1.4volts input sens. with the gain at 26 db and input impedance at various settings 24, 28, 42, 57 kohm. You cannot get away with a passive unit...
Now my main cocern ia the NCD module's gain set at 45db......
But let's just wait and see first.
Regards,
Nikos
i am glad you can confirm my findings.
The noise problem (and i believe it is the high gain) is indeed an issue that i believe Lars and other designers should look into.
The XE700 had an 775mv input sensitivity with 31db gain and 17kohm input impedance somewhere along the lines of the rest of the other zappulse modules and that's why you can also put a passive unit as a pre-amplifier.
The Audia power amp has a 1.4volts input sens. with the gain at 26 db and input impedance at various settings 24, 28, 42, 57 kohm. You cannot get away with a passive unit...
Now my main cocern ia the NCD module's gain set at 45db......
But let's just wait and see first.
Regards,
Nikos
beppe61 said:
Hi,
That's the very point I was making. One module has far worse EMI performance, sure sign of a poor layout, amongst other things which demonstrate a lack of understanding.
Heterodyning means audible difference frequencies between modules.
So one module suffers from it (NCD), the other does not (UcD), and no, with one module unpowered, you only hear the usual hiss, not the heterodyning, which confirms it is exactly that. So be prepared to pay extra for a clock to synch them with, or even more for the extra case/psu to go full mono if you've got high efficiency speakers and dont' want to hear that with NCD. It really needs the very best wiring otherwise you're going to hear alot of wistling in your music, as I did when I first got it.
Regards,
Chris
Not at all Mr. Beppe,
I believe you had the right idea. In fact yesterday I did the test you mentioned just to confirm it for you and to ensure I wasnt' making things up. I've had only one module powered before, but not to check for that specifically.
Space is key, and so going fully mono would provide the best isolation. However it is indeed a shame such an expensive measure is a requirement, when it really shouldn't be, as proven by other modules.
Best Regards,
Chris
I believe you had the right idea. In fact yesterday I did the test you mentioned just to confirm it for you and to ensure I wasnt' making things up. I've had only one module powered before, but not to check for that specifically.
Space is key, and so going fully mono would provide the best isolation. However it is indeed a shame such an expensive measure is a requirement, when it really shouldn't be, as proven by other modules.
Best Regards,
Chris
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