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NAD 3020 Rebuild and Upgrade

KentTeffeteller said:
An NAD 3020 recapped or not is still a budget high end receiver. The electrolytics by now are tired, replace them with good quality capacitors but don't go overboard. Use it as a 30 watts/channel receiver and they are OK. Don't ask more of it.
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True, but that still fails to take into account the giant-killing qualities this little amp had back in the day. It was reviewed against some much more expensive equipment, and still managed to show them a thing or two. I wish I could find some of those old reviews.

jheu02 said:
Looking good. What are you finding spec-wise on the resistors you've pulled?
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Resistors all seem to be in-spec, but that wasn't the reason for changing them.

Lee.
 
I compared a 3020 to a Yamaha CA 600 & an Inca Tech Claymore

I've kept the Yamaha & let the others go so I would say while its your time & money you are spending there are better amps out there & better worth spending money on
 
Good job Leesonic. You work looks superb. I would probably not change the resistors because I would be afraid of losing the original voice. I wouldn't want to lost the magic. That said, when this is done you will have first hand knowledge when this project is complete. First hand knowledge is best! I have done similar restorations and I always learn. That's the real reward.
 
Finally got the thing back together at last. I actually had it powered up last week, but kept hearing this funny noise from it, so I shut the power off right away. It turned out the power switch had gone bad and was arcing. I had to wait for a new one from Mouser, and a new surge suppressor for it as well. I tried to tidy up the wiring as best I could, so it didn't look quite so much like a birds nest inside.

Here are some pictures :

NAD3020rebuild11.jpg


NAD3020rebuild12.jpg


NAD3020rebuild13.jpg


NAD3020rebuild14.jpg


NAD3020rebuild15.jpg


NAD3020rebuild16.jpg


You know what the worst part is? I haven't had a chance to listen to it yet. I had it out in the garage about an hour ago, setting the bias and offsets. The bias range was 5-11mV across a 1 ohm resistor which they neglect to tell you about in the 3020 service manual (but is mentioned in the 7020 manual). I set the bias right at 11, so I can say "this amp goes to 11"...

I will post my listening impressions when I get space and time to set it up.

Lee.
 
Here it is, sitting with the matching 4020 tuner that I just recapped. Keen eyed viewers will notice I replaced the stock 3mm LEDs with 5mm ones. I didn't use anything special, just standard 20mcd ones, but they are a lot brighter than the originals.

How does it sound? I was listening to it the other night, using an unconventional setup of a Sony CD Walkman (which has a 1-bit DAC, that's why I bought it) and a pair of DCM KX10 Series 2. Even though the speakers weren't in anything like the correct listening position, I started hearing things I hadn't heard before.

Based on the number of albums I have, and the number of times I've been to see them, I have to say the Average White Band are my favorite band. I started to notice the bass line clearer than I've ever heard it before. And the bass drum, it sounded like I could actually hear the felt pad hitting the drum skin on the intros to certain tracks.

Maybe I'm imaging it. But like I said, the speakers weren't in any way the right position, plus they were off to my left as I was typing on the computer keyboard exactly like I am now. But I found myself stopping and looking round at the speakers, thinking "wow, I haven't heard that before".

I must add that the speakers were not connected when I took this picture. At 97dB/2.83V, the DCMs are plenty efficient, so that with just the 1 watt LED flashing on the amp, it's pretty loud in this room...

Lee.

NAD3020rebuild17.jpg
 
Very nice thread with some nice pictures. Do you have any extended listening thoughts?

Altogether, how much did it cost you to do the refurb, resistors, caps, and transistors, LED, and power switch included?

And sorry, do you have a list of the parts you ordered and used?
 
What a great thread and job bringing a 3020 back to life! The 3020 was my first hi-fi amp and I thought it was a great amp. Wish I had one today.
 
I had one too, but I didn't get mine until 1984 or so. I sold it in the 1990s for a reason I can't fathom now, luckily you can still find them. Nice update and service and thanks for showing us the pictures!
 
mech986 said:
Very nice thread with some nice pictures. Do you have any extended listening thoughts?

Altogether, how much did it cost you to do the refurb, resistors, caps, and transistors, LED, and power switch included?

And sorry, do you have a list of the parts you ordered and used?
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A list of componants you replaced would be swell.

Also, have you considered upgrading the Transistors? I've heard there's an upgrade doing the rounds?
 
mech986 said:
Very nice thread with some nice pictures. Do you have any extended listening thoughts?

Altogether, how much did it cost you to do the refurb, resistors, caps, and transistors, LED, and power switch included?

And sorry, do you have a list of the parts you ordered and used?
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Since I rebuilt this, I've listened to it with lots of different pairs of speakers, including some that aren't that efficient. It has never failed to amaze me with the sound quality. As I said it previous posting, I find myself looking around at the speakers thinking "I've never heard that before".

I reckon it must be about $60-70 all in for parts. If you can hold tight, I am making up a spreadsheet with all the parts used, including Mouser part numbers... because I'm going to build another one...

ubuntupunk said:
Also, have you considered upgrading the Transistors? I've heard there's an upgrade doing the rounds?
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Upgrading to what? If you mean the outputs, they are already massively over specified for an amp this small. I've seen the 3055/2955 combo used on amps rated at 150w. Somewhere else I heard them mentioned as being "slow". Well, we're only amplifying audio signals here, do we really need 200mhz outputs?

As for just being sold, yeah, I sold it. But only because I have another 3020 that was a parts unit that I plan to bring back to life. This time, all the transistors will be replaced as well, most of them are missing anyhow. I also have a 1020 pre-amp that uses the same circuit board, they just didn't fully populate it. I might turn this into a 3020 turbo, with an uprated power supply for the power amp stage, using a compact toroidal transformer. It might even get four outputs per channel, who knows? The only limitation is the small case these things came in.

Lee.
 
I'd really like to see the parts list once you get it written up.

I have a 3120 that I bought new and it needs the power switch as well.

Plus a recap couldn't hurt either! :)
 
leesonic said:
Since I rebuilt this, I've listened to it with lots of different pairs of speakers, including some that aren't that efficient. It has never failed to amaze me with the sound quality. As I said it previous posting, I find myself looking around at the speakers thinking "I've never heard that before".

I reckon it must be about $60-70 all in for parts. If you can hold tight, I am making up a spreadsheet with all the parts used, including Mouser part numbers... because I'm going to build another one...



Upgrading to what? If you mean the outputs, they are already massively over specified for an amp this small. I've seen the 3055/2955 combo used on amps rated at 150w. Somewhere else I heard them mentioned as being "slow". Well, we're only amplifying audio signals here, do we really need 200mhz outputs?

As for just being sold, yeah, I sold it. But only because I have another 3020 that was a parts unit that I plan to bring back to life. This time, all the transistors will be replaced as well, most of them are missing anyhow. I also have a 1020 pre-amp that uses the same circuit board, they just didn't fully populate it. I might turn this into a 3020 turbo, with an uprated power supply for the power amp stage, using a compact toroidal transformer. It might even get four outputs per channel, who knows? The only limitation is the small case these things came in.

Lee.
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Another happy NAD owner though!
 
Lee, what an excellent write-up for a amp deserving better quality parts.
I am glad I still have mine from buying new back in the day.
I re did all my led`s as well to 5mm but went green for the 1, 5, 10 and yellow for the 20 and red for 35.
Thanks for the list making the job easy.
Going to get another one, will be following the turbo amp job with interest.
 
Yup great post..
After recapping, I'm now onto the diodes.
Suggest upgrading the pot to an alps 50k RK27
 
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Great job on the 3020 as it was looking pretty hideous in stock form. I am sure just redoing the original solders helped a lot but modern caps and tight tolerance resistors are always worth it. Nice upgrade on the outputs too.

Ron-C
 
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