Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

Hypex Ncore
Hypex Ncore
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
Closed Thread
 
Thread Tools Search this Thread
Old 26th December 2011, 09:38 PM   #1021
fredex is offline fredex  New Zealand
diyAudio Member
 
Join Date: Jul 2005
Location: New Zealand
@Bruno. Best wishes from a very happy customer (UcD180ADs). I progressed from tubes to class D via a little Sonic Impact...........ah the clarity.
Your latest efforts have me intrigued. I like the way you take the time to answer questions in a no-nonsense manner. UcD is good engineering.

Last edited by fredex; 26th December 2011 at 09:41 PM. Reason: typo
 
Old 27th December 2011, 12:12 PM   #1022
tiki is offline tiki  Germany
diyAudio Member
 
tiki's Avatar
 
Join Date: Feb 2004
Location: Dresden
Hello,
Quote:
Originally Posted by Bruno Putzeys View Post
OK I'm off for the holidays.
Thank you, that you aren't.
You spent some recreative days hopefully.

80mW mean 79dB SPL in a 90 dB SPL/1W speaker, quite well to be heard, when switched on or off. As it is at my UcD180-amp without using the on/off control pin and at the PSC2.400, which uses the control as I believe. I can tolerate that short click although it could be less noticeable.

The 12" Woofers in the PSC driven monitors show at least 1mm (outward) offset after switching on. This is much worse because this shifts the operating point significantly, causing unnecessary Bl(x), Kms(x) and L(x) distortions just around the operating point in the "small signal" range.
50mV (not specified for UcD400 OEM) should show at the B&C 12NDL76, 4.5 Ohms, 18N/A, 3N/mm (Klippel data) negligible 0.01mm offset. It seems to be significantly more. I did not measure the offset voltage though.

Cheers, Timo
__________________
tiki
 
Old 27th December 2011, 12:17 PM   #1023
StigErik is offline StigErik  Norway
diyAudio Member
 
StigErik's Avatar
 
Join Date: Feb 2008
You misread my post. Its not 80 mW but 0,08 mW. That's 1/1000 or 30 dB less....
__________________
dipoles dipoles dipoles dipoles dipoles dipoles dipoles dipoles and dipoles
 
Old 27th December 2011, 12:19 PM   #1024
pieter t is offline pieter t  Netherlands
diyAudio Member
 
Join Date: Apr 2009
Quote:
Originally Posted by StigErik View Post
You misread my post. Its not 80 mW but 0,08 mW. That's 1/1000 or 30 dB less....
1/1000 is minus 60 dB.

Last edited by pieter t; 27th December 2011 at 12:22 PM.
 
Old 27th December 2011, 12:21 PM   #1025
StigErik is offline StigErik  Norway
diyAudio Member
 
StigErik's Avatar
 
Join Date: Feb 2008
No, it isnt. When talking about power the math is like this:

Decibel - Wikipedia, the free encyclopedia
__________________
dipoles dipoles dipoles dipoles dipoles dipoles dipoles dipoles and dipoles
 
Old 27th December 2011, 12:24 PM   #1026
pieter t is offline pieter t  Netherlands
diyAudio Member
 
Join Date: Apr 2009
You are right Stig Erik, I was thinking voltages...
 
Old 27th December 2011, 01:33 PM   #1027
tiki is offline tiki  Germany
diyAudio Member
 
tiki's Avatar
 
Join Date: Feb 2004
Location: Dresden
Of course, I was wrong, thanks.
The clicks are well audible however, in particular because of the HF content.

The Klippel measurements for the interested
__________________
tiki

Last edited by tiki; 27th December 2011 at 01:37 PM.
 
Old 27th December 2011, 08:25 PM   #1028
noah katz is offline noah katz  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Mountain View, CA
Quote:
Originally Posted by StigErik View Post
You misread my post. Its not 80 mW but 0,08 mW. That's 1/1000 or 30 dB less....
In any case, it's DC, so the result is not SPL but a tiny amount of woofer cone excursion.
__________________
-----------------------------------------
Noah
 
Old 27th December 2011, 11:42 PM   #1029
wilbur-x is offline wilbur-x  Tibet
diyAudio Member
 
Join Date: Dec 2005
Is there any drawbacks attaching the amp module direct to the woofer magnet? (Magnetic stray field intermodulation, fatiguing failures etc?)
If no, you may afford the very length of 5 cm Audioquest Everest
 
Old 28th December 2011, 10:55 AM   #1030
Bruno Putzeys is offline Bruno Putzeys  Europe
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
@tiki could you measure the DC offset on the PSC and let me know?
@wilbur-x I wouldn't do that. The inductor could get biased. According to an industrial customer of ours the've actually had failures caused by the amp module being to close to the magnet. The amp module at the time wasn't ours but I see no overriding reason why ours shouldn't suffer as well.
__________________
There's a time for everything, and this is not it.
 

Closed Thread


Hypex NcoreHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Hypex Ncore vs. NAKSA AlliumPorrum Class D 1 26th May 2015 07:36 PM
Problem with Hypex Ncore Koifarm Class D 29 13th October 2014 07:32 AM
Any news on hypex ncore 2.0? JZatopa Class D 1 13th August 2013 11:30 AM
Hypex UcD700 vs NCore Earbound Class D 25 15th March 2013 05:10 PM
Building a Hypex Ncore... Jabbejokker Class D 0 7th March 2013 10:08 PM


New To Site? Need Help?

All times are GMT. The time now is 01:58 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki