Hydra scart switch – no signal for virtually all systems

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This topic contains 9 replies, has 4 voices, and was last updated by  nmalinoski 2 weeks, 2 days ago.

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    I have just retired 4 old Joytech scart switch boxes that ran to a Sony PVM in favour of a 16 port W-Hydra and OSSC combination to a Dell Ultrasharp 1920×1200 panel.

    However, I’m starting to pull my hair out with the Hydra – it’s so particular about what it will and won’t sync to. So far I’ve tried the following (all known-good, previously working):

    System / Hydra Sync? / OSSC Direct Sync?
    BBC No Yes (no active components)
    Jaguar No Yes (no active components)
    SNES No Yes (sync on luma cable)
    SMS No No
    MD No No
    Saturn No Yes (original Sega RGB scart cable)
    Gamecube Yes Yes
    Atari STE Yes Yes
    MSX2+ No Yes
    ZX Spectrum +3 No Yes

    Only the PAL Gamecube and the Atari STE work so far, I was surprised with the MD and SMS not working even to the OSSC directly, but I’ll give a new cable a shot with those two; but everything else works great when I skip the connection to the Hydra and go direct to the OSSC AV1 input.

    I still have an Amiga 500, 1200, NeoGeo AES and CPC 464 to try (waiting on replacement PSU’s for the latter), but I’m not holding out much hope based on the current results.

    Surely people are not having this much trouble with ‘fancy’ scart cables? I spent a fortune on this thing. Can anyone point me to a supplier of known-working scart cables that are being used with those above consoles and the Hydra?…. oh, and that don’t cost £30 each…. I can’t justify spending more than the cost of the switch on cables alone.




    I’ve not used my Hydra in a while, but I think there were some firmware updates for it, did you get it direct from Lotharek or second hand?



    It’s brand new from Lotharek about 6 weeks ago.

    Just bought two new csync type cables from for the MD1 and the SMS1 and now the OSSC is happy with those, though still nothing when they’re connected through the Hydra, and those cables definitely seem to be in-spec; they have the resister and capacitor on the sync line to bring it down from TTL levels (which supposedly the Hydra doesn’t cope with).

    Also managed to test my Amiga 500 and 1200 – the 500 works but the 1200 doesn’t, thought I haven’t had the time to see if there is any physical difference between the two scart cables.

    I’m now sitting here with a full 16 port wide-Hydra switch and I’ve got less than 6 devices of my original 16 that will work through it.



    So following some advice from Lotharek I’ve opened up the scart connectors of several of the above consoles (MD1, SMS1, SNES) and measured the voltage of the sync line (scart pin 20), some worrying results:

    MD1 (fitted with 220uF cap and 470Ohm resistor – and my multimeter confirms as such) : 3.22v!!!
    SMS1 (as above) : 1.13v
    SNES (wired as sync-on-luma) : 2.02v

    Since the lotharek states the Hydra follows the scart spec of a 1v max sync signal these are all out of spec.



    Yeah Retro Computer Shack aren’t known for making very high quality cables.



    You need to measure the voltages with a 75Ohm load so for example while connected to the OSSC.

    SNES sync on luma should drop to 1v with a 75Ohm load (0.3v sync+0.7v video)



    Well I’m no further forward with this.

    I’ve tried remaking cables to the specifications as recommended (with the correct cap and resistor), but I am unable to get any of the consoles listed previously to work with it (although the MD and SMS, as well as the SNES, work perfectly through the OSSC with the remade, in-spec, cables). It’s such a huge pain in the ass when all the stuff is known-working.

    Frankly I’m fed up with the Hydra. It has been just about the biggest waste of money I’ve ever spent on something that simply didn’t work.

    If anyone has any recommendations for an alternative (I need 15 to 16 ports), then I’d be interested in hearing them.

    I still have my old Joytech and Thor scart switchers, so I could dig them out, but they take up a stupendous amount of room compared to the wall mounted Hydra.



    did you look into updating the firmware on your Hydra?



    I didn’t, but I had already been in discussion with Lotharek over the device (it was bought way, way after the last updated firmware was released; just this year, in fact] and he mentioned nothing about it… just asked me to test all of the individual cables and consoles and see what they were outputting.

    Frankly I haven’t got the time or patience to do that (and what? build bespoke cables for each and every variant – since he won’t give any guarantees or guidance on which cables to buy), and I’m not sure that I agree it is something, as consumers, we should have to do. When a standard Saturn won’t work with it using an original Sega RGB scart cable (amongst the 20 or so variations of consoles and cables), then that says to me the device is built to too tight a tolerance.

    In the meantime I’m going to have to find a way to hook up those old Joytech and Thor AV switchers, since I can’t use anything (other than the STe and GC) at the moment.

    If anyone is interested in my findings, I’ve got them all documented on my blog:



    Probably won’t help the situation, but my understanding of SCART is that the sync signal is supposed to conform to consumer video voltages, which is 1V peak to peak, where the range is -0.3V to +0.7V, not 0 to +1V; and anything outside of that, even if it seems to work with the OSSC, I would expect to be risky to use long-term.

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