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

Solid State Talk all about solid state amplification.

Need help with NAD C350
Need help with NAD C350
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
Thread Tools Search this Thread
Old 25th September 2009, 05:55 PM   #1
Stonecape is offline Stonecape  Sweden
diyAudio Member
Join Date: Feb 2009
Default Need help with NAD C350

I have searched a bit for a similar problem, but didn't find anything.

Here is my problem:

When I power on my amplifier, a relay is clicking and the Soft Clipping LED is flashing then the relay releases again, then it starts over. It clicks and flashes about ones every second.
I noticed it first when I turned on the amp after it had been off for a while. Then I let it go clicking away for some minutes. After a while it clicked and flashed less frequently, then it stopped and it switched on and worked as before. I guess it slightly changed a value on some component as it got warm.

I suspect I have some old capacitor somewhere that needs to be replaced.

Before I had the problem with the power LED going red, but with help from some forum thread I managed to find the faulty capacitor then.

I can add that I have not done anything special, also, nothing changes if I turn off soft clipping.

I would be happy for any help I can get!

Best Regards,
  Reply With Quote
Old 25th September 2009, 08:20 PM   #2
anatech is offline anatech  Canada
diyAudio Moderator
anatech's Avatar
Join Date: Jun 2004
Location: Georgetown, On
Need help with NAD C350
Hi Vincent,
Well, you already know that the protection circuit is working. You can not assume anything until you have more answers though. It would be unusual for a capacitor to cause this problem, not impossible.

I don't have a schematic for this model. Do you know if it's the same as another, or can you send me the manual or schematic for this?

Now, I'd suggest your first step in troubleshooting would be to look at the output from each channel with an oscilloscope as the amp turns on. You will probably see a DC offset (a complete guess on my part) on one channel, causing the protection circuit to operate. You may also have a power supply fault affecting the actual protection circuit. Look at the supply voltages that run that circuit. Again, use your oscilloscope. Your initial vertical sensitivity should be 10 V /cm or higher to start with. Trigger in the line frequency as I'm thinking you may have a supply fault and it doesn't matter what you trigger on for a DC fault. You just need to have a sweep to observe.

Let us know what you find.

"Just because you can, doesn't mean you should" my Wife
  Reply With Quote


Need help with NAD C350Hide 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
Need help with NAD C350, protection! silversweden Solid State 0 19th January 2008 07:47 AM
Nad C350 burbeck Solid State 0 18th December 2007 02:32 PM
looking for a nad c350 schematic neurot Solid State 0 4th December 2006 06:29 PM
Tweak/mod NAD C350 Pound0sound Chip Amps 7 27th February 2004 10:49 AM
Tweak/Mod NAD C350 Pound0sound Solid State 0 9th February 2004 03:01 PM

New To Site? Need Help?

All times are GMT. The time now is 10:20 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio