price: 57.99 GBP platforms: Spectrum
Clear HDMI output, compatible with all spectrums
Comes in kit form and requiring a Pi Zero which you must buy separately for HDMI licensing reasons.
Easy to put together, the only soldering is the header pins onto the Zero.
Fully compatible with all Sinclair ZX Spectrum models and 'fully transparent'; any other device should work fine (see compatibility chart) when connected to the throughput edge connector.