Thursday, August 4, 2016

Re-cap on NAD 3020 Stereo Amplifier

A few weeks back I started hunting for a turntable and amplifier. My dad had his old kit boxed up in my parents' garage and he was happy to give the NAD 3020 amp and Onkyo CP-1010A turntable a new home!

After connecting all the gear, everything sounded good (so, so good), but occasionally the right stereo channel would drop out. A sharp tap on the amplifier would bring it back. Apparently this is symptomatic of failed or failing capacitors, because electrolytic capacitors are generally not designed to last 30 years or more.

I found the service manual for the NAD 3020 online and was amazed to find a full design circuit diagram, parts list, and labelled circuit board wiring diagram. Replacing the caps was going to be easy.

I put together a quick parts list of all the capacitors I had to replace - 42 in total. Only the electrolytic capacitors required replacement because the conductive electrolyte inside them can (and did) leak over time. The ceramic and mylar capacitors inside all passed a visual inspection.

I placed a Digikey order (~$60 for the bare minimum parts but I ordered spares and ended up around ~$90) and warmed up my soldering iron. Sure enough, a good number of the caps were trashed:


One daugherboard with caps removed. You can see the gunk where the electrolyte leaked in at least two places.

The order arrived and I started installing new caps Here's that daugherboard back in place. Anything blue or gold in this pic is brand new:

These 2200 μF caps were the biggest, and replaced 4 completely trashed caps on the input power filtering (I think). All the new parts were different brands and dimensions than the old ones, but that's okay. For cap replacements, as long as the capacitance is the same and the voltage rating matches or lightly exceeds the original, you should be good. Or so I read.

Powered back up!

The first thing I noticed was that everything sounded a bit sharper, but the amp still has a beautiful warm tone. When I listen to music on this setup, I am amazed to hear new details in songs I've heard hundreds of times - instrumental trills, soft vocals, basslines, and more.

14 comments:

  1. When I originally commented I clicked the -Notify me when new feedback are added- checkbox and now every time a comment is added I get four emails with the same comment. Is there any approach you may take away me from that service? Thanks! professional web design

    ReplyDelete

  2. Can I just say what a relief to find someone who actually knows what theyre speaking about on the internet. You undoubtedly know the way to deliver a problem to light and make it important. Extra people have to read this and perceive this facet of the story. I cant believe youre no more common since you undoubtedly have the gift. business ideas singapore

    ReplyDelete
  3. My partner and I stumbled over here coming from a different web address and thought I might as well check things out. I like what I see so now i'm following you. Look forward to looking over your web page for a second time. branding agency singapore

    ReplyDelete
  4. Nice post. I was checking constantly this blog and I am impressed! Extremely helpful information specially the last part :) I care for such information a lot. I was looking for this certain information for a long time. Thank you and good luck. ecommerce website builder

    ReplyDelete
  5. Thanks so much for giving everyone an extremely superb possiblity to check tips from this site. It is often very great and also full of fun for me and my office peers to search your blog not less than three times in one week to read through the fresh guides you will have. And definitely, I'm so at all times contented for the powerful things you serve. Certain two tips in this posting are certainly the very best we have all had.
    seo singapore

    ReplyDelete
  6. Really enjoyed this post post, can there be in whatever way I will receive a message sent to me once you publish a brand new post? Private Jet

    ReplyDelete
  7. Fantastic beat ! I would like to apprentice while you amend your web site, how can i subscribe for a blog web site? The account helped me a acceptable deal. I had been tiny bit acquainted of this your broadcast provided bright clear idea. T shirt supplier in Singapore

    ReplyDelete
  8. Thank you a lot for giving everyone an exceptionally spectacular opportunity to read from this web site. It is always very nice plus jam-packed with amusement for me personally and my office peers to search the blog more than thrice in 7 days to study the new tips you have got. Of course, I am just certainly pleased with all the tremendous inspiring ideas served by you. Certain 1 ideas in this article are undeniably the finest we have all ever had. guardianship and homestay

    ReplyDelete
  9. Wow that was unusual. I just wrote an incredibly long comment but after I clicked submit my comment didn't show up. Grrrr... well I'm not writing all that over again. Regardless, just wanted to say superb blog!
    full grain leather

    ReplyDelete
  10. Only Blizzard or its licensees have the right to host the Game. You may not host or provide matchmaking services for the Game, or intercept, emulate or redirect the proprietary communication protocols used by Blizzard in connection with the Program, regardless of the method used to do so.

    hosting plan

    ReplyDelete
  11. Many of the long established terms have become lost in the noise of the instant communication of misused terms. * editing - sorting, picking the best of the best for possible publication * photo editor - an actual live person working in at a newspaper, news agency or magazine.

    Singapore marketing executive

    ReplyDelete
  12. When I originally commented I clicked the "Notify me when new comments are added" checkbox and now each time a comment is added I get four e-mails with the same comment. Is there any way you can remove people from that service? Many thanks!
    important to have good content

    ReplyDelete
  13. Hello! I've been reading your weblog for a while now and finally got the bravery to go ahead and give you a shout out from Houston Texas! Just wanted to mention keep up the great job!web development company in india

    ReplyDelete
  14. Neat blog! Is your theme custom made or did you download it from somewhere? A design like yours with a few simple adjustements would really make my blog shine. Please let me know where you got your theme. Kudos
    click here to find out more

    ReplyDelete