I made loads of those amplifier modules including a project for a local cinema using 5 of them. My power rails were 51 volts and a 93 watts prior to clipping into 8 ohms. I never had any issues with oscillation which some people did, never had any blow up either. My kits had mica washers but other wise looked the same, exactly the same FETs. I seam to recall they did sound very good but in these days had no way to measure THD. I had completely forgotten about them, nice memories.

Fab video Nick, brought back many happy 😊 memories, what a good time we had 👍 very impressed with the testing side of the project, a lovely response across whole audio spectrum, Mosfets rule 👌,do not think you would get that on a valve amp.

When I built an amplifier using these Maplin modules I used 55-0-55 volt supply rails and measured 120W into 8 Ohms. Also the THD at 100W measured 0.01% which is correct according to the spec. I found that running each module at 50mA quiescent current was fine and didn't increase the THD. These Maplin modules are capable of astonishing sound quality which is far better than many extremely expensive commercial hi fi power amplifiers. You can even short the speaker outputs with a screwdriver and the mosfets will survive. However, you will end up with a damaged screwdriver and an immediate need for a clean pair of underpants.

I recognise the amp modules. They went into an awful lot of home made disco equipment back in the day and I must have fixed dozens of them. I have a memory of them going into self oscillation but I don’t remember the details. I used to enjoy building them I wonder if there is a copy on the market. This video brought back happy memories. Great video thanks.

...it reminds me of those Sinclair amplifier modules of the early seventies...