I do have another EPROM board with GT North chips which have identical hand written labels with the same year however the South East chips are printed and not hand written.
I would certainly be interested to see if there is any difference.
I have read GT North A and South East A and played them however there is no difference between them and the others.
Thanks a lot for all of this. However the format is still incorrect - if it was really VOX ADPCM, the audio would be completely clear. My guess is that it could be either MS ADPCM or IMA ADPCM, with the same 16kHz sample rate and 4-bit encoding. I suspect the Piccadilly Line announcements that we have yet to properly convert to also be in one of these formats. Another clue is that some of the ScotRail files are encoded as MS ADPCM. Looking around the internet it seems to be incredibly hard to find software able to convert these formats back to WAV, although it appears there are some command line tools if you are skilled in that area. If not those formats then it could be one of the many other versions of ADPCM - including possibly a bespoke version.
I believe the Pic line announcements are not too dissimilar from these, I remember seeing TFL say that the system was by Whiteley Electronics well the PCBs which the 365 announcement EPROMs are on also say Whiteley Electronics.
Correct. And the system found on ADtranz/Bombardier 'Star' trains is a further development of this Whiteley system. At some point they switched from EPROM to PCMCIA cards, which is where the 73TS PCC file comes from. It is also evident from the 378 Overground announcements, that those trains were still using PCMCIA and BIN files. These import in much the same way as the 365 files, with distorted audio, but of course the original audio is also included in that case.
I'm currently trying all sorts of sound conversion/editors to see if they not only support the format but provide a good result.
Indeed, this is what I'm having a play about with this evening. No luck so far, but I'm sure a breakthrough will happen.
I have been playing around with raw too, also used a couple things like ffmpeg and SoX.
I assume the result was similar with those tools?
No actually, if anything they were worse!
Interesting - my guess is that the audio must have been saved in some forgotten 90s format - it's just a case of trying to find out which one!
I'd assume its some sort of ADPCM as by using those we have got the closest.
www.railforums.co.uk
I have tried using sox previously but it just results in a result slightly worse than what Switch provided.Do you think it would be possible to get these announcements working in Train Sim? I would love to be able to hear these whilst driving!
Also, I found a post from a while ago about the files for station announcements and converting them - could there be any similarities?
Ketech Cellia Drummond and Only Woman announcements publicly availible?
From what I heard in September 2022 was that Atos was installed on the GOBLIN, Gospel Oak and Stratford stations and then the rest it is unkown what supplier they wil chose this was from the FOI request from LO. If KeTech has Emma recordings it could make sense to switch it to them like they did...
See post #49
That’s a shame. I wonder if importing the files onto a virtual machine running perhaps windows 98 would have better results - from what I have seen online, windows used to have an ADPCM codec installed.
View attachment GTNorthA.mp3
And the very noticeable audio clipping.
Definitely the best result so far!
Presumably you can slot your EPROM boards into this? If so you would probably be able to get higher quality recordings of the announcements - there is probably a test mode which plays all of them.
It already has EPROM boards in it!
Something else of interest will be the audible chime for manual PA announcements - on certain units (I believe the ex WAGN units), the chime was slightly different. I'm also interested to see what can be accessed via the keypad.