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

Very noisy Hypex UCD400HG
Very noisy Hypex UCD400HG
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 13th September 2018, 11:29 AM   #1
jamiematrix is offline jamiematrix  United Kingdom
diyAudio Member
 
Join Date: Aug 2007
Default Very noisy Hypex UCD400HG

I have a Hypex amp with 2 UCD400HG (with HXR) and two SMPS400A400 power supplies. I've had it 3 or 4 years now. It was fine for a long time but has now started making a lot of hiss, and also some strange kind of 'interference' crackling type sounds. It can vary in loudness from time to time. If I unplug the audio input XLR cables, the noise gets very loud, which makes me wonder if this is somehow related to grounding issues? It happens in both channels of the amp and if I only power up one side at a time, I still have the problem so it would seem odd for both independent channels to develop the same fault.

Any suggestions on a solution before I try and ship it to Hypex for possible repair?

Here is a photograph:
Attached Images
File Type: jpg Hypex.jpg (991.8 KB, 155 views)

Last edited by jamiematrix; 13th September 2018 at 11:34 AM.
  Reply With Quote
Old 13th September 2018, 06:34 PM   #2
Reactance is offline Reactance  South Africa
diyAudio Member
 
Reactance's Avatar
 
Join Date: Jun 2005
Location: Cape Town
Quote:
Originally Posted by jamiematrix View Post
I have a Hypex amp with 2 UCD400HG (with HXR) and two SMPS400A400 power supplies. I've had it 3 or 4 years now. It was fine for a long time but has now started making a lot of hiss, and also some strange kind of 'interference' crackling type sounds. It can vary in loudness from time to time. If I unplug the audio input XLR cables, the noise gets very loud, which makes me wonder if this is somehow related to grounding issues? It happens in both channels of the amp and if I only power up one side at a time, I still have the problem so it would seem odd for both independent channels to develop the same fault.

Any suggestions on a solution before I try and ship it to Hypex for possible repair?

Here is a photograph:
Such expensive amplifiers, for the price...I no longer trust Hypex products they seem like a hyped up audio brand, I was evaluating these for a friend so no more.
__________________
There’s nothing worse than the smell of burned output transistors!!
  Reply With Quote
Old 13th September 2018, 07:00 PM   #3
TBTL is offline TBTL  Germany
diyAudio Member
 
Join Date: Oct 2013
Not related to hiss or crackling, but for your own safety I would recommend to look at the case earth connection again. The earth wire must be longer than the neutral and live wires. Furthermore, routing it through a terminal block does not seem safe to me.
  Reply With Quote
Old 14th September 2018, 01:28 PM   #4
Baka is offline Baka  Montenegro
diyAudio Member
 
Join Date: May 2005
Location: Podgorica, Montenegro
Quote:
Originally Posted by Reactance View Post
Such expensive amplifiers, for the price...I no longer trust Hypex products they seem like a hyped up audio brand, I was evaluating these for a friend so no more.
Just for the record: I strongly disagree with your opinion having 2 UCD400HG (with HXR) and two SMPS400A400 power supplies for several years.

Top notch solution for the asking price. They can be even further improved with some careful tweaking.
  Reply With Quote
Old 18th September 2018, 05:31 AM   #5
Michaelofcn is offline Michaelofcn
diyAudio Member
 
Join Date: Sep 2018
Quote:
Originally Posted by jamiematrix View Post
I have a Hypex amp with 2 UCD400HG (with HXR) and two SMPS400A400 power supplies. I've had it 3 or 4 years now. It was fine for a long time but has now started making a lot of hiss, and also some strange kind of 'interference' crackling type sounds. It can vary in loudness from time to time. If I unplug the audio input XLR cables, the noise gets very loud, which makes me wonder if this is somehow related to grounding issues? It happens in both channels of the amp and if I only power up one side at a time, I still have the problem so it would seem odd for both independent channels to develop the same fault.

Any suggestions on a solution before I try and ship it to Hypex for possible repair?

Here is a photograph:
How was it going on? sent them back to the factory? I am going to use these two module for my new project. just afraid of the quality of Hypex modules.
  Reply With Quote
Old 18th September 2018, 05:59 AM   #6
chermann is offline chermann  Austria
diyAudio Member
 
Join Date: Jan 2017
Location: Vienna
Quote:
Originally Posted by TBTL View Post
Not related to hiss or crackling, but for your own safety I would recommend to look at the case earth connection again. The earth wire must be longer than the neutral and live wires. Furthermore, routing it through a terminal block does not seem safe to me.

jop...
please check the bottom plate and scratch the black collered surface away and reconnect the earth connection. mybe this black collered surface has to scratched away at other points too.
  Reply With Quote

Reply


Very noisy Hypex UCD400HGHide 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
FS: HYPEX UcD400HG raelman Swap Meet 7 24th January 2017 08:13 PM
Hypex UcD400HG + HxR & Hypex SMPS400A400 Wiring Questions Nirvana5253 Class D 3 12th March 2015 05:26 PM
FS: Hypex UCD400HG+HXR + PSU trex Swap Meet 0 25th February 2012 11:31 AM
FS: Hypex UcD400HG+HxR Francois K Swap Meet 3 25th February 2012 04:23 AM
Hypex UCD400HG with HxR (and without!) cowanrg Swap Meet 7 4th July 2009 07:03 AM


New To Site? Need Help?

All times are GMT. The time now is 02:38 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki