hypex ncore - Page 41 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Vendor's Bazaar

Vendor's Bazaar Commercial Vendors large & small hawking their wares

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd September 2011, 02:37 PM   #401
tiki is offline tiki  Germany
diyAudio Member
 
tiki's Avatar
 
Join Date: Feb 2004
Location: Dresden
Hello Bruno,
may I compare these to the "Hypex NC1200+SMPS1200 Test Data" in the PDF from Hypex' website, "THD vs Power (100Hz, 1kHz, 6kHz)"? The conditions may be different. So the main improvement is the removal of the THD bump between 10 and 100W?
Thank You!
Attached Images
File Type: png nc400thdvp_comparison_.png (20.8 KB, 1065 views)
__________________
tiki
  Reply With Quote
Old 23rd September 2011, 02:47 PM   #402
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
jmbulg: yes, except I used a lab supply here so output power on this graph is a bit optimistic. Otherwise the test conditions are the same.

david: The question hasn't been asked yet For audiophile-grade DSP work consider the ever-on-the-horizon DLCP board. It'll come but the amount of work on the PC software end has been underestimated.

tiki: yes, the 400 power stage is a bit friendlier in terms of how it transitions from soft to hard switching. I hope this improved behaviour makes up for the lower power output.
__________________
There's a time for everything, and this is not it.

Last edited by Bruno Putzeys; 23rd September 2011 at 02:52 PM.
  Reply With Quote
Old 23rd September 2011, 02:50 PM   #403
diyAudio Member
 
Join Date: Sep 2011
Does that imply that the PSC2.400 isn't audiophile-grade ? ;-)

Last edited by David dP; 23rd September 2011 at 02:55 PM.
  Reply With Quote
Old 23rd September 2011, 02:51 PM   #404
jmbulg is offline jmbulg  Belgium
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by Bruno Putzeys View Post
jmbulg: yes, except I used a lab supply here so output power on this graph is a bit optimistic. Otherwise the test conditions are the same.

david: The question hasn't been asked yet For audiophile-grade DSP work consider the ever-on-the-horizon DLCP board. It'll come but the amount of work on the PC software end has been underestimated.

tiki: yes, the 400 power stage is a bit friendlier in terms of distortion.

The only question which remains is then: when ? for hopefully !
  Reply With Quote
Old 23rd September 2011, 02:54 PM   #405
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
We're still targeting delivery in 2011. Keep your fingers crossed other work doesn't get in the way.
__________________
There's a time for everything, and this is not it.
  Reply With Quote
Old 23rd September 2011, 02:56 PM   #406
jmbulg is offline jmbulg  Belgium
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by Bruno Putzeys View Post
We're still targeting delivery in 2011. Keep your fingers crossed other work doesn't get in the way.
Then I know what I will put on my christmas list
  Reply With Quote
Old 26th September 2011, 07:38 PM   #407
diyAudio Member
 
Join Date: May 2005
Location: New York
Default HYPEX NCORE INQUIRY

Hello,

I few questions I would appreciate help with:

Please refer to the attached diagram of the proposed use of Hypex amplifiers to drive the Analog signal processorLinkwitzlab Orion.

The DIY audio version of the NCORE will apparently be around 400w-8 Ohms. The requirements for the Orion drivers are very low in comparison: 25 w (tweeter and midrange), 150-200w (dual woofers). What is is critical seemingly, is the "first watt" rather than high power.

Is power reduction via voltage rails recommended or possible?

Is the NCORE optimized for 400w and would it suffer sonically if the output was reduced?

With 400w, there is enough power to supply both woofers, but there is a question about preferred wiring configuration. Should the woofers be wired in parallel or in series?


Mr. Putzeys had alluded to designing an "ultimate" input stage for the NCORE. As someone with limited technical knowledge, this would be ideal, as opposed to having a detailed knowledge and ability to tweak the design. Can this be clarified any further at this stage?


Furthermore, I am unclear what sonic advantages OEM manufactures may have instituted with their own input buffers (Island Audio / Genesis Audio, etc.) for the earlier UCD series. Is this:

1. merely audiophile marketing hype

2. did they actually improve on the the Hypex design, or

3. tailor impedances of a standard Hypex input buffer.


Is there a way to tailor the NCORE input impedance relative to Analog Signal Processor (Active Crossover) for the different channels?


Are there any RFI issues with the NCORE to consider such as:
Proximity of amplifiers to each other.
Orientation and placement of PSU to amplifier.
Choice of chassis: Aluminium, wood, Plastic (Plexiglas / Perspex).
Proximity to Analog Signal Processor?

Will a DIY manual be released with tips and guidelines for the NCORE?

Thank you.
  Reply With Quote
Old 27th September 2011, 06:43 AM   #408
Nevod is offline Nevod  Russian Federation
diyAudio Member
 
Join Date: Nov 2007
Send a message via ICQ to Nevod
I also have a question, though more of a theoretical one.

How would an nCore design fare if the normal output filter would be replaced with high-frequency step-up transformer and some sort of notch filter, connected to an electrostatic driver, with AF feedback derived after the filter - although with different feedback ratio of course? Would that be possible?

It would be interesting if there would finally be an cheap way of powering DIY ESL headphones with good performance.
  Reply With Quote
Old 27th September 2011, 07:11 AM   #409
diyAudio Member
 
Ouroboros's Avatar
 
Join Date: Dec 2003
Location: Nottingham UK
Nevod.
You cannot step up the audio output voltage of a class-D amplifier using a high frequency transformer. Although the PWM is switching at (say) between 250kHz and 350kHz, the spectrum of the signal goes all the way down to the lowest audio frequency.
I wish it was easy though, as I design PA/VA amplifiers providing a 100V output feed!
It is theoretically possible to achieve what you want by using a slightly different modulation scheme, together with full-wave synchronous 4-quadrant rectification at the secondary of the step-up transformer. This technique is used for lightweight 50/60Hz sine-wave invertors, but I do not know of any successful switching amplifier using a similar technique that can acheive the full audio range at low distortion.
  Reply With Quote
Old 27th September 2011, 07:41 AM   #410
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
@Fountainhead
Thx for posting the question here - I preferred it because I'm following this thread actively and anything I answer here saves me from having to answer similar questions.

With regards to reducing the power output of any class D amplifier. If you reduce the supply voltage, thus reducing the output power, the entire THD vs power graph shifts to the left by the same amount. For instance, the 25W distortion maximum of the NC1200 will move to 12.5W if maximum output is halved by dropping the supply voltage 30%. All class D amps have this behaviour. Given that distortion is so low I don't think it's a serious issue but strictly speaking you do not get a "better 1W amp" when you scale the supply voltage down.

The correct wiring of speaker units is not amplifier related. Loudspeaker designers tend to avoid series wiring because any antiphase motion of the woofers is not damped at all. I don't know how serious the problem is with modern units but subharmonic oscillations have been reported in the past.

The buffer design is finished. It is the usual two op amp arrangement except that the op amps are discrete and perform better than the current crop of "super chips". For the fanatics, the input stage is degenerated (with an inductor a la jensen to boost DC gain) and bootstrapped. The compensation is a T network around an ahuja transimpedance stage. Input bias current is compensated with a pot because any other method added non-linear capacitance.

Although the buffer on the UcD module is chip based and can be improved upon (as I'm doing with the NC400) the reason why VARs like to roll their own input buffer is mainly psychological. Uncharitably you could call it "audiophile hype" but one has to understand that they're taking a commercial risk buying their core technology from an OEM supplier. If a supply and a UcD module is all there is in the box they need something to differentiate them from direct competitors and from companies which sell similar products more cheaply.
A refreshing departure from this is Hexateq who make no bones about using the stock product because the chassis they put it in is drop-dead gorgeous and that alone is worth money.
Another reason why people may want to make changes is because they are after a specific sound (i.e. they don't even want the product to sound like others based on the same amp). They may call this sound "better" if they want but objectively the word is "different".

I should say that with industrial Ncore customers we're now insisting that if they add their own own buffer circuits, the measured performance of the completed amp should be as good as that of the stock unit. Of course this reduces the scope for moulding the sound, but that's what we want. We've seen at least one negative review of a UcD based product where the sound was substantially determined by an external input stage. Luckily for us the reviewer took care to point this out (having heard standard UcD circuits before). But it's not something we like to see happening with Ncore.

The input impedance of the buffer is high, and therefore suitable to be driven by anything. There's no need to tailor it. What you might want to tinker with is the gain. For this reason a gain setting resistor is located in a clearly marked and accessible place.

RF-wise, NCore modules behave at least as well as UcD modules, which are famous for their lack of interference problems. Essentially you construct your project as it suits you mechanically.

We try to provide fairly complete documentation. However, it's hard to foresee every question so occasionally we add stuff in response to support questions or forum discussions.

@Ouroboros: thanks
@Nevod: To clarify further, note that the output coil is an inductance in series with the output while a transformer is an inductance across the output. You can put feedback around a step-up transformer. The core size can then be slightly reduced because you need to design only for maximum output / lowest frequency before hard saturation.
__________________
There's a time for everything, and this is not it.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hypex problem, who can help Hansms Class D 9 18th August 2013 06:49 AM
Hypex steveww Class D 14 18th November 2010 01:44 PM
Question for those who have tried hypex smps with hypex modules avian Class D 12 3rd March 2009 09:30 AM
Hypex UcD 180AD + signal wires, Power Supply ST, Hypex Transformer TR100A c10h12n2 Swap Meet 7 7th July 2007 03:55 PM
FS: Hypex UcD 400/180AD, hypex toroid Archmage Swap Meet 4 14th November 2006 04:23 AM


New To Site? Need Help?

All times are GMT. The time now is 05:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2