A message from Steve Roberts for those who can't decide which region to go with:

This is a bit of a heads-up for US fans... There's now a confirmed release date of 26th of June in the States. It would be incredibly helpful if you could get your pre-orders in (it's on Amazon already, I imagine it's also on other retail sites) sooner rather than later. America is a really big linchpin in the future of this Blu-ray range, so strong pre-order sales will help create confidence in the range and encourage early commissioning of the next set. Spread the word!

Over 500 classic episodes from the 26 seasons of classic Doctor Who will air worldwide on the live streaming video platform Twitch from May 29th.

Fans will be able to watch adventures from the first seven Doctors – from 1963’s An Unearthly Child to 1989’s Survival – while chatting live to thousands of other viewers around the world.

This epic screening of classic Doctor Who from May 29th until July 23rd follows Twitch’s successful marathons of Power Rangers, Bob Ross: The Joy of Painting and Mister Rogers' Neighborhood.

In addition to the episodes being screened in blocks - three times a day, around the world, completely free - fans can also enjoy a heap of exclusive Twitch content.

Doctor Who emotes

Viewers who subscribe to the TwitchPresents channel will gain access to a pack of exclusive emojis, themed around the classic Doctors. Who needs words when you can react with a bemused Sixth Doctor?

There will be prizes

For fans in the US, UK, and Canada, Twitch is hosting a giveaway each week of the event, including a grand prize trip to London Comic-Con. For details on how to enter and full terms and conditions visit: https://watch.twitch.tv/DoctorWhoSweepstakes.

Pre-show content hosted by Yogscast

Join leading UK digital content creators The Yogscast for a series of exclusive specials, introducing each era of the show - the highs, the lows, the behind the scenes stories, the monsters and the gaffes. With a cast of Doctor Who screenwriters, experts, fans, and even a former companion, the Yogscast's Turps, and resident Doctor Who expert Matt Toffolo discuss why modern audiences should LOVE classic Doctor Who (as if we needed a reason!).

Mark your 500 Year Diaries! Starting May 29th, you can tune in each day, Monday to Friday from 11am Pacific US / 7pm UK to catch episodes on Twitch.tv/TwitchPresents.

Steve Roberts (DW Restoration Team):The problem is a polarity reversal of one channel of the audio. When one speaker cone is pushing out, the other is pulling in. Instead of centring the audio midway between the speakers, it throws it completely out into wide stereo. It might sound acceptable on a TV depending on your setup, but if you try to listen on headphones, it will probably make you feel ill (I'm not kidding).

Because surround information is encoded as phase differences, if you listen on a surround setup, all of the sound will come from the rear speakers. If you try to mitigate this by doing something like switching your system to All Speaker Mono, you'll get silence, because the amplifier adds together the left and right channels to create a mono channel before sending it out to each speaker. Because the two channels are completely out of phase, adding the two together completely cancels out the signal, producing silence. There is no good way to fix this, save listening in stereo mode and unplugging your left hand speaker and moving your right hand speaker to be in front of the TV.

We weren't given the opportunity [to do Quality Control ourselves]. As usual, there simply isn't enough time. Everything is done on too short a notice, every step of the way is left until the last minute. There is, however, a full QC done on each individual item by a professional QC company and on the discs by the authoring house, which is why the fact that this fault has got right through to replication is baffling everyone.

You can watch it in stereo mode and swap the speaker cable round on the back of one speaker to re-invert the inverted signal.