NCD questions

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wtfaidh said:
Hi Lars,

Thaks for this reply. The NCD is running on Mission 770 speakers for the last couple of weeks....

Not only the resistor is red-hot but the coil as well.

If this is normal behavior, o.k. but than I have to apply forced cooling by means of a small fan wich would be a pitty because of the additional noise and another trafo as well...

Cheerio, Eric.

Eric,

If you add some extra aluminium to your cabinet you will NOT need forced cooling.

Check my mono blocks in my previous post. As you can see I have a lot of aluminium there. The internal construction is 12mm aluminium panels bolted together and I used ''cooling paste'' between the aluminium panels. I have also used ''cooling paste'' between the internal 12mm panels and the side panel of the cabinet that is a small heat sink. This works really well to dissapate the heat :)

Of course the coil still gets hot, but it's no problem when the cabinet is designed to move the heat away!

I bought the cabinets here www.audiokit.it very nice to deal with, so highly recommended.

Cheers,
Morten
 
Re: Re: NCD monos

Desmo said:
Desmo said:
I just finished my NCD monoblocks and have started breaking them in :)

Anyway, here are some links to the pictures of my new amps :D

http://www.badongo.com/pic/648738
http://www.badongo.com/pic/648737
http://www.badongo.com/pic/648736
http://www.badongo.com/pic/648735
http://www.badongo.com/pic/648734

Cheers,
Morten


Hello

Could you please give some description on how it sounds – do you think it’s true that it competes with amps costing 4-5 times the cost of a full kit to 1000 Euros? ref. kit from Nasotech.

Best regards
 
No, but not really interested either . Sympatic initiative, but no thank you….. I'm looking for the best possible sound.

Fortunately Lars is still experimenting "I will also have a sound improving upgrade soon. (Involving OPA627, and other stuff)."

Although I don't know if the OPA627 is an improvement....
 
wtfaidh said:
No, but not really interested either . Sympatic initiative, but no thank you….. I'm looking for the best possible sound.

Fortunately Lars is still experimenting "I will also have a sound improving upgrade soon. (Involving OPA627, and other stuff)."

Although I don't know if the OPA627 is an improvement....

Probably rigth but the "others" are also experimenting othervise now new vesions would come out and no improvments would ever happen. Lars often tend to be quite open about at least some of his "research". As do some other manufactures. But that said I have had some of the early versions of the Zap Pulse with minor issues that realy should not have reached end users. HTe NCD is a long way since the first Zap Pulse models so hopefully not that much errors pass QC these days ;o)

Rgds
 
Project Devils arose again!

Finally got both the equipment, all the stuff AND the time to put my NCD dual mono amp together.

Mounted everything on my aluminum mounting board, connected the wires all over the place, checked, double checked and double checked again. Everything was fine and done right.

So lets connect the cd-player and the Accuphase preamp and feel the wonderful sound from my Thiel floorstands. But NO LIFE!!!! , just some weak terrible sound as from a mobile phone.

Check again and again and again. Check for missing power, missplaced connections, cold solderings to input or output terminals. No, no and no again. Nothing wrong.

Mail Dexa, mail to NewclassD, phone to Dexa - No replies yet. More checking - ground leaks this time, and WWHHAATT ! ! ! ! ! !

The "aluminum" mounting plate is leading current - has no resistans at all. So everything mounted to it, including the metal chassi was all connected to each other. The "aluminum" was not pure and must be mixed with something else to make it leading current.

So lets start this project again - - - - - Isn-t that a cute story or what????????

THe picture was BEFORE the reality striked my project :bawling:
 

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Quote:"The "aluminum" mounting plate is leading current - has no resistans at all. So everything mounted to it, including the metal chassi was all connected to each other. The "aluminum" was not pure and must be mixed with something else to make it leading current".

Sorry, but i don´t understand what eventually was the fault?! Is the mounting plate made of aluminum and in case it is it should lead current. But I guess that it is made of some material (unknown to me) that you thought was an isolation material, right?
BTW; resistance, chassis. ;)
Spelling, aluminum or aluminium:
http://en.wikipedia.org/wiki/Aluminium#Etymology_and_nomenclature_history
 
I don't understand it either..!!! Of course a plate made of aluminium will lead current..!!??

But looking at the picture I might get a clue about what you mean, and what's wrong.

I can't see the insulation material between the power supply diodes, and the aluminium plate. Have you mounted the insulation material supplied with the kit? If not, you have the answer to your problem...

Cheers,
Morten
 
You´re abslolutely right both of you, aluminum lead current. But I had got in my mind it didn´t - as well as it is non magnetic. Maybe from the reasoning about aluminum case in favour to metal cases. Totally wrong of me.

Anyway, the insulation material was/is there, but all the stuff are mounted on the plate which will be a grundplate together with the whole chassi which I don´t know if that is too good?

The problem with amp was not the grounding anyway. Measured everything. The incoming signal path from connector to amp had resistans 0 so there should be good contact - but something was wrong anyway. Almost no signal was coming into the amps.

Switched to two 75Ohm cables per channel instead and there where sound, lots of sound! Not the very best though as the system also included a cheap MP3player and a €60 DVD from my son playing on some Boston A40 which hasn´t been playing for 15 years.

When I realized the wherer sound I switched the internal cables from 75 Ohm types to four twined wires from a CAT5 cable.

Did just connect the NCD to my Accuphase preamp, Lars C modded Pioneer CD and Thiel speakers, all connected with fourtwinned wires with some nice Furutech connectors.

Now we are talking. For he first time in 28 years it seems that my Accu power amp will not be connected in again.

Nice and open sound and and a great and crisp perspective, wow! ! !
 
Boys, we´re playing! ! ! ! !

Switched my old speaker cables to newly built four twinned 1,4mm2 one core painted wires. WOW, this thing is playing.

Steely Dan late albums, Madonna Confessions on the dance floor, Bridget Jones diary are all well produced well sounding albums and the are really getting a new life here. Can´t stop playing.

The humm and hiss are gone after some change of ground wireing, and evreything is just great - after more that one year. . . .

Nest step. . . Maybe some other op-amp, and definetely disk-drive playing. New deals... Throw out your CD-players and go disk wise. WAV ripped with AEC (freeware) and a good D/A is the way to go with this great amp.....

By the way, this is a great (and a fairly sheap DIY) way of improving any kind of cables and sound of your system: http://www.svalander.se/teknik/kablar/flata.htm
Even my not interested wife really heard the differens.

Now I´m going for some more wine & music and maybe some XXX
 
Sharkythefrog said:
Boys, we´re playing! ! ! ! !

Hallo "Sharkythefrog" Congratulations...!!! Looks grat. Always nice to end up with an working system, nah ? tell you : The NCD1 sound is really addictive.

And if working on your system : Jus take care to bleed the caps before removing any parts and don't forget to remove the shorts before powering-up again...

Mine is working now for several months and I just can't get enough of it. I expect to finish te casings of my mono-blocks this year.

For the moment it's hooked up to a Squeezebox 3 running FLAC's right now. Not the best possible source.

I will be testing an USB-DAC(s) as well since Windows-Vista is the first OS supporting A-Synchronous data transfer and not ******* up the data when using it's proprietary volume control (as XP and MAC-OS 10 do...).

But I'll probably end up wint no pre-amp and just a simple strereo pot-meter directly connected to my CD player after all. Who needs more..?!

Cheers, Eric.
 
Hi guys,

Just finished (one of) my NCD monoblocks this afternoon after they have been sitting around for almost a year now :(

Anyway, I have a couple of (newbee) questions I hoped someone with more skill than me would take the time to answer:

(1) the noise floor is rather high in my case. I am not totally sure if this is due to higher gain in the new poweramp, or the amp itself. When I mute the pre (Classe CP-50) the tweeter noise (almost) dies. When the music plays the noise is heard in the quiet passages. How do I find the cause of this noise? I am running balanced signals all the way through...

(2) With everything connected properly there is a finite resistance between the enclosure and the ground of balanced signal. Could someone explain this newbee if this is OK, and how to properly ground the various components of such an amp?

(3) Due to space constrictions I have had to run the loudspeaker cables close to the power supply board - specifically the diodes on board. Is this a problem? Are these diodes emitting noise that could be picked up?

(4) The connection used in the enclosure came without any instructions. The connection is through a short 'tube' on the inside. Are these for soldering, and if so how do you prevent 'cold' connections only through the tin?


I would appreciate very much if someone could answer (some of) these questions :)


Best,
Bitnissen
 
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