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View Full Version : Need some help with a technical scart question please.



Ed.D
17th February 2015, 21:17
Hi it's me again,

It's not the pins this time. :oops: :lol:


So I'm working on a Neo Geo MVS and the Supergun Mk IV has a passive stereo audio out connector (with a mono/stereo switch). In the supergun manual it says...

"You can use a wide range of passive speakers, from 2W to 15W but ideally i recommend you use stereo passive speakers with a combined speaker power of 10W and each speaker having 8 ohms impedance."


Can somebody advise if I can patch a couple of wires (L/R audio) plus a ground wire from the stereo out socket into the analogue audio wires in the scart cable which plug into the TV? Can the scart input of a TV handle the power and impedance of the passive audio output?


Many thanks,
Ed.

roy_bates
17th February 2015, 22:01
no,it looks like an amplified signal i wouldn't do it.

basically if it can drive speakers it shouldn't be wired directly to an input on your tv.

TheCorfiot
17th February 2015, 22:03
Good god, dont even try it...lol

:)

Ed.D
17th February 2015, 22:29
Ok thank you gentlemen. I thought passive meant unamplified, no worries.

roy_bates
17th February 2015, 22:31
actually im wondering if the signal could be attenuated to line level? hmm ill have a think.

possibly using some passives like,two 10k and two 1k resistors.

fitzsteve
17th February 2015, 22:38
I use mine with normal amplified PC speakers and it works fine. There is a volume control on the mvs motherboard which I have set quite low.

Maybe with the volume low it would work on a TV too?

Ed.D
18th February 2015, 09:27
Thanks guys, strange that they bring video through the scart but not audio.

I'll install an extension cable to bring the stereo audio signals out to the case panel.

Cheers,
Ed.

roy_bates
18th February 2015, 09:58
something like this:

http://www.amibay.com/attachment.php?attachmentid=83338&d=1424253291

personally,i would probably use audio line transformers at a appropriate rating and it would be isolated completely..
but hey,this was 5 mins,lol

maybe someone could confirm this would work?

Ed.D
18th February 2015, 10:55
Thank you Roy I appreciate your time looking at this. I'm not too worried about my old TV but as the MVS is not my kit I think I'll not try it if there is some potential risk of damage.

Ed.

roy_bates
18th February 2015, 11:46
there's no risk of damage to the mvs mate as far as i know,we were more worried about the tv on the receiving end.

sir_beaker
18th February 2015, 12:20
If not, I can always make a Neo Geo sandwich with these babies :thumbsup:

http://www.whathifi.com/ruark-audio/mr1/review

roy_bates
18th February 2015, 13:04
and...they look like they take a line input as well...

Ed.D
18th February 2015, 15:03
I've got a vintage Marshall 4 x 12 cab from 1965, model 1960B that should work :) just needs rewiring and a new tolex cover.

Ed.D
23rd February 2015, 22:56
something like this:

http://www.amibay.com/attachment.php?attachmentid=83338&d=1424253291

personally,i would probably use audio line transformers at a appropriate rating and it would be isolated completely..
but hey,this was 5 mins,lol

maybe someone could confirm this would work?




You need to patent this Roy, it works a treat! :thumbsup::bowdown: Thanks for your time and expertise!

I needed 6 hands and asbestos fingernails to hold all the resistors and wires for soldering! :lol:

Ed.