Need help w/ NAD preamp problem - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 3rd April 2004, 01:07 PM   #1
Jim B is offline Jim B  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Ann Arbor, MI
Question Need help w/ NAD preamp problem

Hi everyone,

I recently hauled my NAD amp and preamp out of the basement after 5 years of non-use, and hooked them up to my cd player, and later my tape deck.

Basically, I get a very weak sound. If I put my headphones in the amp jack, I get a weak sound. This is also the case when speakers are hooked up.

When I put the headphones into the jack on the preamp, the sound is even fainter; barely able to hear it on full volume.

When listening through the amp, the tone and balance controls on the preamp to affect the sound, so they are working.

I've eliminated the interconnects as a source of the problem.

I took the preamp into my local stereo shop where I had purchased it 20 years ago, and they had the same problem with it, very weak sound.

They did refer me to a repair shop, but I thought I would give it a shot myself first. Not to be cheap, but I my son is starting to get into stereo gear, and I thought we could work on it together.

Thanks for any advice you could give.

Jim B.
__________________
Jim B
  Reply With Quote
Old 4th April 2004, 11:30 AM   #2
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
Make sure the tape monitor is off.

Make sure the pre amp-power amp coupler switch is on or the jumpers installed.

Try removing the j-fet mute transistors.
  Reply With Quote
Old 4th April 2004, 01:21 PM   #3
Jim B is offline Jim B  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Ann Arbor, MI
Thanks for your help.

But with a separate amp and pre-amp would there be jumpers or a coupling? Wouldn't that just be in an integrated amp?



Jim B
__________________
Jim B
  Reply With Quote
Old 4th April 2004, 11:35 PM   #4
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
My tips were intended to be generic, for NAD receiver and integrated owners too.

Some Hafler preamps have problems with muting fets too.

I've also had problems with Yamaha tuners.
  Reply With Quote
Old 5th April 2004, 12:40 PM   #5
Jim B is offline Jim B  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Ann Arbor, MI
Thanks again
__________________
Jim B
  Reply With Quote
Old 6th April 2004, 08:09 AM   #6
hjelm is offline hjelm  Sweden
diyAudio Member
 
hjelm's Avatar
 
Join Date: Nov 2003
Location: Västerås
What model is the preamp?

As for just guessing a bad PSU might cause this.
Basing this on the fact that the sound semms ok(?) but at a low volume.

Look at the voltage you have when driving the headphones.
__________________
Hjelm
  Reply With Quote
Old 6th April 2004, 12:21 PM   #7
Jim B is offline Jim B  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Ann Arbor, MI
It's a model 1020, made around 1982.

As far as I can tell, the sound seems OK, just weak.

Thanks for your help
__________________
Jim B
  Reply With Quote
Old 7th April 2004, 07:56 AM   #8
hjelm is offline hjelm  Sweden
diyAudio Member
 
hjelm's Avatar
 
Join Date: Nov 2003
Location: Västerås
Does anyone have a schematic?
I think it is fun but without schematic i cannot help.
__________________
Hjelm
  Reply With Quote
Old 7th April 2004, 01:09 PM   #9
Jim B is offline Jim B  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Ann Arbor, MI
Thanks Hjelm,

I don't have a manual, but will see if I can find a schematic on the web somewhere.
__________________
Jim B
  Reply With Quote
Old 8th April 2004, 01:03 AM   #10
soma is offline soma  China
diyAudio Member
 
Join Date: Apr 2004
Location: nanjing
Default Step by step

Pls follow below steps to repair,if there are any founds,pls let me know,I will try to give a quickest comments.
1)Pls check voltage of Q901(2SD669) e,to check whether is +23.3V and check if Q902(2SB649) e is -20.2V or not?
2)Try to use tweezer to short d and s of Q509(2SJ111) and Q510(2SJ111),and check whether output is normal in the corresponding channels.
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
P88 Preamp problem Curioprop Solid State 5 17th July 2007 02:01 AM
26 preamp problem NickC Tubes / Valves 7 13th February 2006 01:12 PM
preamp ps problem Briney Tubes / Valves 12 18th November 2005 12:21 AM
Mic preamp problem kimarin Solid State 1 29th October 2004 09:11 PM
X2 preamp problem... audionuts Pass Labs 1 28th October 2004 02:28 PM


New To Site? Need Help?

All times are GMT. The time now is 03:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2