I recently replaced my Nad c372 with BTE upgrade passive pre and a Quad QSP so I'd owned the Nad c372 for about a year and as a temporary fill in and it didn't ever display problems.
It was sold on eBay and the new buyer said that after listening to a couple of tracks
at normal levels it made a popping sound and smoke came out from the right side.
I now have it back and it won't power up at all I have removed the cover and though there is a smoke mark on the right side there is also a smaller mark on the left.
Now admittedly I don't know the inside of an amp from the back side of a donkey there are no obvious signs of burned or leaking components.
My question is it worth fixing or do I cut my losses and sell on as is.
Cosmetically it's in excellent condition.
It was sold on eBay and the new buyer said that after listening to a couple of tracks
at normal levels it made a popping sound and smoke came out from the right side.
I now have it back and it won't power up at all I have removed the cover and though there is a smoke mark on the right side there is also a smaller mark on the left.
Now admittedly I don't know the inside of an amp from the back side of a donkey there are no obvious signs of burned or leaking components.
My question is it worth fixing or do I cut my losses and sell on as is.
Cosmetically it's in excellent condition.
It will cost you about $100 in tools to fix it. DVM $30 analog VOM $20 soldering iron $30, cutters, needle nose pliers, pick, screwdrivers, combo wrenches, safety glasses. pound of solder is about $30, kessler doesn't sell less. ebay solder may be ****.
If you intend to do this multiple times, go for it. If you're trying to make a buck, or have storage problems for the kit, sell as "amp for parts".
I've got amps in two rooms in town house, one in my summer camp, plus a lightweight mono mixer/amp for performance out: there is method to my madness. Original amp took 300 watts and used $90 tube sets that last 8000 hours, new ones use much less power emitting 1 w/ch average, use $40 output transistor sets that can last 40000 hours, and sound better. Besides, I have 6 electronic organs of various capabilites, and repair 3 organs and 2 PA amps for church friends. Repaired a TV and a computer monitor this winter.
If you intend to do this multiple times, go for it. If you're trying to make a buck, or have storage problems for the kit, sell as "amp for parts".
I've got amps in two rooms in town house, one in my summer camp, plus a lightweight mono mixer/amp for performance out: there is method to my madness. Original amp took 300 watts and used $90 tube sets that last 8000 hours, new ones use much less power emitting 1 w/ch average, use $40 output transistor sets that can last 40000 hours, and sound better. Besides, I have 6 electronic organs of various capabilites, and repair 3 organs and 2 PA amps for church friends. Repaired a TV and a computer monitor this winter.
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Without seeing the fault condition and looking at the amplifier, running some tests, who knows.
Whatever a BTE upgrade and Quad QSP means ... I have no idea.
I see there is one, still with box and remote control, on fleabay starting at £35.
One in USA for $270
Whatever a BTE upgrade and Quad QSP means ... I have no idea.
I see there is one, still with box and remote control, on fleabay starting at £35.
One in USA for $270
Thanks for you reply. I meant to say upgraded BTE which is a passive pre built by BTE Designs there is a standard model and then there are upgraded models mine is the later it has a better volume pot. It was built for me to match the Quad Elite QSP Power amp that I already owned.
When a survey was carried out long ago as to the typical cause of a non working power amplifier it was found to be abuse of the output .
Fuses aren't perfect and take a finite time to blow especially if not fast blow and when considering fuses at the output think on thermal cycling and the effects on distortion widely argued over in an old EW article.
Practically apart from volume control abuse -- children poking things into any opening --alcohol "abuse " (spilled on amp ) --dropped or thrown at partner by non hi-fi appreciating partner the one major problem ,accompanied by much blackening was blown output devices and or driver section BJT,s in the many amps I have repaired.
If it is the output that's blown I would not be so quick to take it back.
Fuses aren't perfect and take a finite time to blow especially if not fast blow and when considering fuses at the output think on thermal cycling and the effects on distortion widely argued over in an old EW article.
Practically apart from volume control abuse -- children poking things into any opening --alcohol "abuse " (spilled on amp ) --dropped or thrown at partner by non hi-fi appreciating partner the one major problem ,accompanied by much blackening was blown output devices and or driver section BJT,s in the many amps I have repaired.
If it is the output that's blown I would not be so quick to take it back.
This may help: NAD C372 to restore or not
You basically need to disassmble the burned boards. Visual inspection of failed parts is a great way to start. I find that scrubbing bubles bathroom cleaner works great to clean the PCB once it is removed from the amplifier. A clean board is also much needed when visually inspecting the components for this like: burned resistors, open resitors, leaking caps and fried transistors.
Then get the schematic and work backwards from the output to the input. Keep an open mind. Sometimes a cheap open resistor is enough to fry the amp.
Good luck!
You basically need to disassmble the burned boards. Visual inspection of failed parts is a great way to start. I find that scrubbing bubles bathroom cleaner works great to clean the PCB once it is removed from the amplifier. A clean board is also much needed when visually inspecting the components for this like: burned resistors, open resitors, leaking caps and fried transistors.
Then get the schematic and work backwards from the output to the input. Keep an open mind. Sometimes a cheap open resistor is enough to fry the amp.
Good luck!