The “VOLKSAMP”
The NAD 3020 can be summarized as the “VOLKSAMP”, an amplifier for the people just like the Beetle was the “VOLKSWAGEN”.
Yesterday I decided, on visiting the town center, I should pop by the one of three swap-shops doing trade in our “one-horse town”. Usually they have nothing of real value, chip-board closets, cheap TVs and ply-wood guitars. Yesterday turned out to be my lucky day! To my utter amazement there, between Fung Cha DVD players and Sakyno “Multi-Channel” amplifiers stood a help-less little NAD 3020 with a bright orange sticker on its face. After recovering from my mild case of “luck-struck-hee-bee-gee-bees” I grabbed it for a mere $38-50! Wow!
The amplifier most certainly did not belong to a loving owner. It was extremely dusty and downright filthy. After I tested it to confirm it worked I took on the challenge to make it shine again.
Upon opening it up I found that someone replaced the mains transformer for some reason or another. I didn’t worry as the amplifier performed electrically as it is supposed to. The repair-man also connected the LED power indicator to the one tx-tap with a pair of resistors – reason unknown.
I stripped it down completely, removing every last panel, button and screw. I then carefully removed the main PCB and prepped it to be washed with strong detergent (a trick I learnt from a key player in the local hi-fi industry!). I carefully scrubbed the PCB until I was certain all gunk was removed. The procedure was then followed a good rinse with clean, cold water to remove all trances of soap. It was dried using a ETI hairdryer (the type that can burn the hair from your head).
Before I assembled the amplifier again I connected all wires to run a check on it. I also restored the LED connection to its correct place on the PCB. All was fine.
Assembly was a breeze. I even managed to fit a brand new power cord with a two-prong plug for the sake of neatness.
The amplifier now took residence in my main system. Its sound is punchy with great bottom-end grunt. Highs are remarkably extended but can, at times, be a bit brittle. The phono-stage works a treat with my Fidelity Research SUT and Dynavector MC cartridge.
Running the E.A.R. 834P phono-stage (equipped with a Alps attenuator) into the LAB Input (which bypasses the pre-amp section) provides an exciting listening experience from the analogue source.
What a great find and what a great little amplifier! The 3020 may be a budget amplifier but its sound suggests otherwise. It shows that a piece of audio equipment doesn’t have to feature a 25mm thick face-plate from aluminum to sound good. Its not the parts that you use, its how you employ it. The secret is in the design, not the styling. To the designer of the NAD 3020, I salute you!
The NAD 3020 can be summarized as the “VOLKSAMP”, an amplifier for the people just like the Beetle was the “VOLKSWAGEN”.
Yesterday I decided, on visiting the town center, I should pop by the one of three swap-shops doing trade in our “one-horse town”. Usually they have nothing of real value, chip-board closets, cheap TVs and ply-wood guitars. Yesterday turned out to be my lucky day! To my utter amazement there, between Fung Cha DVD players and Sakyno “Multi-Channel” amplifiers stood a help-less little NAD 3020 with a bright orange sticker on its face. After recovering from my mild case of “luck-struck-hee-bee-gee-bees” I grabbed it for a mere $38-50! Wow!
The amplifier most certainly did not belong to a loving owner. It was extremely dusty and downright filthy. After I tested it to confirm it worked I took on the challenge to make it shine again.
Upon opening it up I found that someone replaced the mains transformer for some reason or another. I didn’t worry as the amplifier performed electrically as it is supposed to. The repair-man also connected the LED power indicator to the one tx-tap with a pair of resistors – reason unknown.
I stripped it down completely, removing every last panel, button and screw. I then carefully removed the main PCB and prepped it to be washed with strong detergent (a trick I learnt from a key player in the local hi-fi industry!). I carefully scrubbed the PCB until I was certain all gunk was removed. The procedure was then followed a good rinse with clean, cold water to remove all trances of soap. It was dried using a ETI hairdryer (the type that can burn the hair from your head).
Before I assembled the amplifier again I connected all wires to run a check on it. I also restored the LED connection to its correct place on the PCB. All was fine.
Assembly was a breeze. I even managed to fit a brand new power cord with a two-prong plug for the sake of neatness.
The amplifier now took residence in my main system. Its sound is punchy with great bottom-end grunt. Highs are remarkably extended but can, at times, be a bit brittle. The phono-stage works a treat with my Fidelity Research SUT and Dynavector MC cartridge.
Running the E.A.R. 834P phono-stage (equipped with a Alps attenuator) into the LAB Input (which bypasses the pre-amp section) provides an exciting listening experience from the analogue source.
What a great find and what a great little amplifier! The 3020 may be a budget amplifier but its sound suggests otherwise. It shows that a piece of audio equipment doesn’t have to feature a 25mm thick face-plate from aluminum to sound good. Its not the parts that you use, its how you employ it. The secret is in the design, not the styling. To the designer of the NAD 3020, I salute you!
Looks great, very clean. Well done 
It's possbile the original transformer blew up or the person wanted a larger supply - who knows.
It is probably wise to consider a full replacement of all electrolytics in the amp though. If nothing else, replace those 4 large PSU capacitors.
Also, should you ever want to replace the output transistors, there is a mod you must do if you use modern 2955/3055 pairs. See the other two threads already linked by Salas.
It's possbile the original transformer blew up or the person wanted a larger supply - who knows.
It is probably wise to consider a full replacement of all electrolytics in the amp though. If nothing else, replace those 4 large PSU capacitors.
Also, should you ever want to replace the output transistors, there is a mod you must do if you use modern 2955/3055 pairs. See the other two threads already linked by Salas.
jaycee said:Looks great, very clean. Well done
It's possbile the original transformer blew up or the person wanted a larger supply - who knows.
There is a rumor that some of these 3020s where fitted with under-rated transformers and these gave up ghost quite easily. Could be what happened here with this one. Well the "new" transformer seems to be a bit more beefier than the original.
This bothers me. I had undone these solder-blobs (in picture below). I thought it was the doings of a previous repair guy. Should it be like this?
This is from the COLLECTOR of the 3055 transistor:
Closeup:
The 2955s doesnt have such blobs.
This is from the COLLECTOR of the 3055 transistor:
An externally hosted image should be here but it was not working when we last tested it.
Closeup:
An externally hosted image should be here but it was not working when we last tested it.
The 2955s doesnt have such blobs.
the blobs are there as a solder short, you should only unsolder these to set the bias current, to do this leave them unsoldered and tack a 1k resistor accross then adjust the value of rx1 and rx2 with different values of resistors to make the voltage accross the 1k resistors is 5-12mv, this information is in the service manual for this model and should be referenced as my memory isnt that great.
chris
chris
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