Nad 705 Receiver Pre Amp faulty?

pmpants · 20th January 2013, 12:49 PM

Hi everyone, thanks in advance!
I'm looking at my friends Nad 705 it powers up fine, the protection relays click and the display works, however there's no speaker output.
I've removed the links and connected a source to the power amp sections input, and there's output on both sets of speaker outputs so I imagine the fault is with the pre amp, if I connect a source to say "aux in", and loop an output from either of the tape "rec outs" to the power amp input you get output, but of course the volume control doesn't function.
Has anyone got any ideas where to start looking? The amp has service stickers inside from 3 dates in 1997, and looks to have had some dry joints repaired.
Thanks ever so much
Paul

chicks · 20th January 2013, 02:03 PM

I've had several NAD producrs from the '90's and '00's, every one of which had issues, and were a PITA to work on. Bad solder joints, poor quality caps that dry out. One huge PCB that requires disassembly of the entire chassis to reach the bloen caps.

I prefer '70's gear that uses multiple PCB's, far eaier to work on, and far better build quality than NADs of a certain vintage, in most cases.

pmpants · 20th January 2013, 05:41 PM

Quote:

Originally Posted by chicks

I've had several NAD producrs from the '90's and '00's, every one of which had issues, and were a PITA to work on. Bad solder joints, poor quality caps that dry out. One huge PCB that requires disassembly of the entire chassis to reach the bloen caps.

I prefer '70's gear that uses multiple PCB's, far eaier to work on, and far better build quality than NADs of a certain vintage, in most cases.

I know what you mean, I've recently been busy recapping Quad 405s and 33s and 70's Japanese integrated amps, loving every minute, learning as I go! This Nad is a diffrent beast altogether

TANDBERGEREN · 20th January 2013, 08:02 PM

Theese receivers often have the PSU for the preamp and tuner placed on the preamp-PCB.
The PCB itself often was rubbish, with exremely thin paths and ultrasmall solderpads.
Lots and lots of dried out solderjoints aswell as dried out caps.
But start with the often +/- 18V PSU. Find a way to mount the regulators away from the PCB, and change those caps wich mechanically is tight mounted up to the regulators.

Should be relatively fine when finished.

pmpants · 20th January 2013, 09:00 PM

Thanks Tandbergeren, I have a schematic so I'll take a good look tomorrow, I hope I can revive it for my friend, he really loves it

)

20th January 2013, 12:49 PM	#1
pmpants diyAudio Member Join Date: Nov 2009	Nad 705 Receiver Pre Amp faulty? Hi everyone, thanks in advance! I'm looking at my friends Nad 705 it powers up fine, the protection relays click and the display works, however there's no speaker output. I've removed the links and connected a source to the power amp sections input, and there's output on both sets of speaker outputs so I imagine the fault is with the pre amp, if I connect a source to say "aux in", and loop an output from either of the tape "rec outs" to the power amp input you get output, but of course the volume control doesn't function. Has anyone got any ideas where to start looking? The amp has service stickers inside from 3 dates in 1997, and looks to have had some dry joints repaired. Thanks ever so much Paul

20th January 2013, 08:02 PM	#4
TANDBERGEREN diyAudio Member Join Date: Jan 2011 Location: Fosser, Aurskog-Holand, Akershus, Norway.	Theese receivers often have the PSU for the preamp and tuner placed on the preamp-PCB. The PCB itself often was rubbish, with exremely thin paths and ultrasmall solderpads. Lots and lots of dried out solderjoints aswell as dried out caps. But start with the often +/- 18V PSU. Find a way to mount the regulators away from the PCB, and change those caps wich mechanically is tight mounted up to the regulators. Should be relatively fine when finished. __________________ Sooner or later you end up with TANDBERG

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
NAD 705 strange behaviour, intermittent fault?	flyingtele	Solid State	9	23rd May 2012 12:46 PM
NAD 705 Troubleshooting	jocko_nc	Solid State	6	15th July 2006 08:23 PM
NAD 705 broken output stage?	borges	Chip Amps	3	16th April 2006 04:02 PM
NAD 705 Stereo Receiver Service Manual?	Franz G	Solid State	3	7th April 2006 02:01 AM
Noisy NAD 705	squirrel69	Solid State	6	7th April 2006 01:37 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

20th January 2013, 02:03 PM	#2
chicks diyAudio Member Join Date: Sep 2008 Location: The Big Valley, CA	I've had several NAD producrs from the '90's and '00's, every one of which had issues, and were a PITA to work on. Bad solder joints, poor quality caps that dry out. One huge PCB that requires disassembly of the entire chassis to reach the bloen caps. I prefer '70's gear that uses multiple PCB's, far eaier to work on, and far better build quality than NADs of a certain vintage, in most cases.

20th January 2013, 09:00 PM	#5
pmpants diyAudio Member Join Date: Nov 2009	Thanks Tandbergeren, I have a schematic so I'll take a good look tomorrow, I hope I can revive it for my friend, he really loves it )