NAD 7020 and others.
eBay
3-Way LT1963A Low-noise, Linear Regulated Adjustable Negative Regulated Power Supply 5V 12V 15V OP AMP HiFi DIY RF DAC Amplifier
Aliexpress UK
The covers are washable, but not in the washing machine. You can wash them with sponge and soap under a shower. The other way is to clean them with wet towel. I has a specially designed openable back to accommodate the cables.
eBay
MiCWL CA Series 5200W Power Amplifier Stage Karaoke Audio Speaker Digital AMP 2 4 Channel 2600 Watt
Aliexpress UK
A good idea is to replace all the electrolytic capacitors with new ones. They also have a low ESR. You can also get the factory service manual to the NAD 7060 as an addition. I will send it in PDF format.
eBay
BT-198E Bluetooth Audio Amplifier 35W×2/12V DC/220V AC Input/USB SD AUX MIC Input/Dual Channel Power Amp
Aliexpress UK
NAD 3020A original owners instruction manual hopefully useful to an owner of one of these wonderful vintage amps.
eBay
Wire Harness 10 Pin Plug RCA Car Amplifier Speaker Power Input Wire Harness Compatible with Dual TBX10A Amplifier
Aliexpress UK
I'm not a charity and these aren't readily available. if you need 2 buy 2! if you do this you will be blocked! I have shown a photo of the long type 30mm next to short type 22mm. 30mm type are available from Tom Tom Audio.
eBay
Amplifier for Car Audio High Power 4 Channel 12V Digital Stereo Surround Passive Subwoofer Car Audio Amplifier Max 7800W
Aliexpress UK
It's in good shape, but may show signs of use due to its age.
eBay
SMSL RAW-HA1 High DAC AMP Digital Power Amplifier Chip Support MQA MQA-CD Bluetooth 5.1 LDAC XMOS XU-316 CS43131
Aliexpress UK
A good idea is to replace all the electrolytic capacitors with new ones. They also have a low ESR. You can also get the factory service manual to the NAD 7130 as an addition. I will send it in PDF format.
eBay
TOPPING A70Pro fully balanced headphone amplifier, high-power desktop headphone amplifier 17000mW*2 XLR 4.4
Aliexpress UK
Up for sale is a 5-page review of the NAD 2100 power amplifier that has been clipped from the pages of the respected, high-end audio magazine "the Absolute Sound" in 1990. You will receive the original 5-page print review, clipped directly from the pages of"the Absolute Sound" magazine in 1990.
eBay
Nobsound NS-04G PRO Mini Digital Power Amplifier HiFi Stereo 2.0 Channel Class D Home Desktop Audio Amp 100W+100W
Aliexpress UK