The loss of maplins has made my Amazon boycott somewhat difficult, though not impossible, but there's just no way to get small parts and adapters same day now, always have to wait for delivery. PC world used to have some stuff, but now it's rolled into Currys you only get packaged stuff and peripheral cables and such. Sometimes Screwfix has what I need but it's somewhat rare. They did have a bunch of audio a networking stuff last I looked though.
A lesser known UK option that may be worth checking is ebuyer.com for some of your
A/V, networking and computer stuff. Nowhere near the full range of Maplin/Amazon etc, but they will deliver quickly from UK warehouses - and if you're trying to avoid using Amazon, always worth an extra option.
Their target market are people they can upsell extended warranties, anti-virus, etc to. So if you're buying individual computer components you already have too much knowledge for them to exploit you
Oh I know but they could still make money from me by selling me things that I want to buy from them. I just find it baffling that they don't want to do that.