Interested in discussing the sound quality of NewClassD (and other class d amps)?

[beppe61]

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

Thank you very much Mr Chris for your kind an valuable additional information.
About going fully mono I notice that a lot of audio brands boast about completely dual mono construction for their stereo power amps.
The additional cost for a "monos solution" would be the case and connectors.
I have the feeling, and your words tend to confirm this, that this could be the ultimate solution.

Thanks a lot.
Best wishes,

beppe

 

[classd4sure]

... and additional power supply. It isn't the ultimate solution, but it is a good one!

 

[beppe61]

... and additional power supply.
It isn't the ultimate solution, but it is a good one!

Of course Mr Chris.
Ultimate is maybe too strong of an adjective .
Regards,

beppe

 

[KLe]

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

Thanks marmatsouris
Just to ask
... in what way(s) is the 700xe better than the 2.3se
... how does the 700xe compare to CI Audio, Tact, Jeff Rowland, Sharp etc.

thanks
KL

 

[marmatsouris]

Hi KL,

With regards to the difference of 2.3Se and 700Xe the most interesting was the quality and "projection" of the mid-bass and bass frequencies. It is like the "quantity" of lower notes are more prominent. I know it may sounds strange because class-d amps excel in this region but it is true in my set-up anyway.

In the midrange both designs are very good with a "tubey" sound, lots of harmonics albeit the details the 700xe projects are easier to follow.

The same applies to the high frequencies as well. They are more "controled" through the 700xe modules with my Great Heil tweeters (very fast and reveiling) but with the Esotar tweeter of my Dynaudio Confidence 5, this frequency range is soemhow the same with either modules.

With regards to other class-d designs, i prefer the CI Audio one than the Sharp or Tact ,since it is an honest piece of hi-fi. For someone with a "high-end wallet" the ICE technology implemented in teh Jeff Rowland designs is o.k. also.

Now we have to wait and see how Lars can compete with NCD1. I have just received an e-mail that i should have the units next week.

I'll keep you posted.

Regards to all,

Nikos

 

[Anzgar]

I have now assembled my newclassd and have been playing on it for a week.500VA transformer and 6wire psu.I also tried 4wire psu but I think the sound is actually better when using a separate transformer for the gate driver.
I am in an absurd situation because I have listened to the 700XE let be only for a few hours and just in mono, but the memory of its sound makes me almost unable to review the NCD, all the more as I don't have a couple of 700Xes to make an AB test.If I had been unaware of the 700xe I would have rated the NCD higher than I actually do.
To cut it short, the NCD is excellent;higly dynamic and with powerful, well controlled deep bass and lower middle but I think it's not as good in the treble and in reproducing microdetails as the 700xe - as I remember (for what it's worth).I would like to hear marmatsouris' opinion when he has compared the two modules as he by now should have access to both of them.The amp sounds better the longer it is being played on, it's much better now than the first days.It is also very sensitive to what cables are used from the outpu to the loudspeaker contacts.Changing mine to a better wire made a big difference.
.

 

[marmatsouris]

I have now assembled my newclassd and have been playing on it for a week.500VA transformer and 6wire psu.I also tried 4wire psu but I think the sound is actually better when using a separate transformer for the gate driver.
I am in an absurd situation because I have listened to the 700XE let be only for a few hours and just in mono, but the memory of its sound makes me almost unable to review the NCD, all the more as I don't have a couple of 700Xes to make an AB test.If I had been unaware of the 700xe I would have rated the NCD higher than I actually do.
To cut it short, the NCD is excellent;higly dynamic and with powerful, well controlled deep bass and lower middle but I think it's not as good in the treble and in reproducing microdetails as the 700xe - as I remember (for what it's worth).I would like to hear marmatsouris' opinion when he has compared the two modules as he by now should have access to both of them.The amp sounds better the longer it is being played on, it's much better now than the first days.It is also very sensitive to what cables are used from the outpu to the loudspeaker contacts.Changing mine to a better wire made a big difference.
.

Hi all,

Yes it's been a while since i posted any reply to this thread.

I have also received the modules and i have ordered two power transformers potted in resin at 500VA each with seperate windings for the gate driver ( 6 wire p/s ) but they will be ready next week.

Don't worry Anzgar, i will compare it against the 700Xe ( mind you the transformers with the 700XE modules are 600VA each with different power supply caps ).

I am also thinking the addition of 2 Jensen 4-pole caps (10,000mF) per power supply unit ( this design will be full dual mono ) as with the 700XE one...

I will revert as soon as the project is complete.

Bye for now,

Nikos

 

[KLe]

Hi KL,
...
Now we have to wait and see how Lars can compete with NCD1. I have just received an e-mail that i should have the units next week.

I'll keep you posted.
Regards to all,
Nikos

Thanks marmatsouris
Excellent, look forward to reading your posts

Have you compred the 700XE and CI Audio amps?

thanks
KL

 

[marmatsouris]

Thanks marmatsouris
Excellent, look forward to reading your posts

Have you compred the 700XE and CI Audio amps?

thanks
KL

Hi. KL

I have heard the CI Audio amps in another system but not in direct comparison with the 700XE.

However this comparison could be arranged once i have built the NCD1 also...

 

[H247]

4.pole jensen

Hi Marmatsouris

Remember when you are going to use the Jensen 4. pole E-lytes,
i believe that you are going to let the amps pass through the foil in the Jensen 4. pole, this arrangement will affect the sound, maybe positively due to supply supression or better high frequency response, may be negatively due to incresed impedance through the E-lyt foil, or simply "foil sound".

According to my experiense you might end up with greatly different sounding powersupply's, and this might leede you to make the wrong " conclusion.

You might want to try parallel coupling of 4.pole E-lytes to counter act foil impedance, and gain capacity.

Lastly dont forget a better more honest amp might sound worse in most setups due to quality issues in the rest off the chain.
Remember you are listening to every component in the chain (ex: your powersupply cables will effect sound) , and this is nonsens to many minds, due to lack off experience.

You have to put the same amount off effort into the rest off your setup to achieve the better result.

 

[marmatsouris]

Re: 4.pole jensen

Hi Marmatsouris

Remember when you are going to use the Jensen 4. pole E-lytes,
i believe that you are going to let the amps pass through the foil in the Jensen 4. pole, this arrangement will affect the sound, maybe positively due to supply supression or better high frequency response, may be negatively due to incresed impedance through the E-lyt foil, or simply "foil sound".

According to my experiense you might end up with greatly different sounding powersupply's, and this might leede you to make the wrong " conclusion.

You might want to try parallel coupling of 4.pole E-lytes to counter act foil impedance, and gain capacity.

Lastly dont forget a better more honest amp might sound worse in most setups due to quality issues in the rest off the chain.
Remember you are listening to every component in the chain (ex: your powersupply cables will effect sound) , and this is nonsens to many minds, due to lack off experience.

You have to put the same amount off effort into the rest off your setup to achieve the better result.

Hi H247,

many thanks for your suggestions, they are very helpful when they come from people that they have actually tried things, as i have come across many others that only talk theoretically with no practical experience at all.

I plan to listen to the modules with their original power supplies first and then "upgarde" them with the 4-pole caps. My only concern is, since i will keep the Nippon Chem on the board and just add the Jense caps without taking out the other caps, i do not know whether the overall sound will be affected by the "lesser" caps...Any ideas?

Best regards,

Nikos

 

[novec]

As long as you connect the Jensens in the usual 4-pole way after the original NCD power supply, I'd find it hard to believe that the original caps would ruin anything. But that's just a slightly educated guess.

Wouldn't it be possible to just use the same power supply for both units, or are they on different voltages?

 

[H247]

Hi Marmatsouris

I my expierience adding 4.poles after the original PS will apply most off the 4. pole sound.

But end result coult still be worce, due to mentioned issues.

 

[H247]

Hi Marmatsouris

To get the high frequency benefit from the 4.pole E-lytes you have to lett the charging current pass through both the positive and the negative foil, and then assemble the ground.

This means you will have to split up the groung on the PCB, and then assemble it afther the 4.pole E-lytes.

regards

 

[marmatsouris]

Hi Marmatsouris

To get the high frequency benefit from the 4.pole E-lytes you have to lett the charging current pass through both the positive and the negative foil, and then assemble the ground.

This means you will have to split up the groung on the PCB, and then assemble it afther the 4.pole E-lytes.

regards

Hi H247,

many thanks once again for our insight.

For the time being i will leave things with the p/s as is until the amp is fully broken-in. Thne i will mess around with input IC, input power supply and change of caps at the main power supply.

I am also thinking of not going the Jensesn/T-Net way but towards screw-terminals big caps.

Now that i have received the resin-potted transformers, it will take me a couple of days to put everything together and start listening.

I' ll be back......

Nikos

 

[Painkiller]

I'm a bit interrested in how the midband sounds. Is it very smooth? I have a ZapPulse 2.2 and I find it a little too smooth perhaps. A bit tiresome during long listening sessions. How is that with the NCD? Does your ears start bleeding after listening for longer periods at high volumes?

 

[soongsc]

This thread has been quiet for some time. I looked at the information on the NCD web site and wonder:

The instructions say to connect the transformer to the connector in the 42V-0-0-42V configuration, has anyone tried connecting it in the 42-0-42-0 configuration?

Please don't ask why, since it is a simple test to do to see whether it makes a difference or not for those whom already have it..

 

[Anzgar]

I'm a bit interrested in how the midband sounds. Is it very smooth? I have a ZapPulse 2.2 and I find it a little too smooth perhaps. A bit tiresome during long listening sessions. How is that with the NCD? Does your ears start bleeding after listening for longer periods at high volumes?

I experience the midband far more potent than 2.3 and 2,2SE.It's not aggressive but leaves you in no doubt whether you have listened to some music or not I listened to Miles Davis:"Miles in the Sky" tonight, and the percussion in special was breathtaking to hear.

 

[KLe]

I experience the midband far more potent than 2.3 and 2,2SE.It's not aggressive but leaves you in no doubt whether you have listened to some music or not I listened to Miles Davis:"Miles in the Sky" tonight, and the percussion in special was breathtaking to hear.

Hi Anzgar
Now that your NCD1 is up and running, can you give us a complete comentary on what you think of the NCD1 in your system.

thanks
KL

 

[novec]

I'd definately like to hear your _honest_ opinion on the total experience of it, specially since you're familiar with the 2.3SE I'm listening to now. My change will probably be far more drastic, considering I'm going from 500VA standard toroids and RIFA PEH 200 caps on the 2.3SEs to 1300VA audio core toroids and Jensen 4-poles on the NCDs, but still...

Just waiting on getting my hands on them, Lars seems to have been pretty busy lately...