HDMI to VGA/D-Sub Converter

Dean

Expert Member
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Aug 19, 2005
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2,670
Hi folks,

Looking to link a monitor with only a VGA/D-Sub connector, to a laptop with only an HDMI output.

Vague understanding of signalling leads me to believe that HDMI is digital whereas VGA is analog.
That may be entirely incorrect, but it leads me to my question:

Is there a VGA/D-Sub to HDMI convertor cable/plug available that anyone here has successfully used for the above purpose?

Cheers
 

Pilgrim

Wugger
Joined
Jul 5, 2006
Messages
3,097
You get passive HDMI to DVI converters and you do get DVI to VGA converters. However be careful, not all computers output Analog over the HDMI port. Only if you hava analog will the HDMI-DVI-VGA route work.

If you don't have Analog on your HDMI source you will need an Active HDMI -> VGA dongle such as recommended above. They should not be more than R150.
 

sajunky

Honorary Master
Joined
Nov 1, 2010
Messages
13,124
All HDMI to VGA converters are "active", as HDMI port do not carry analog signals.

Are the same? From the digital part - capable of decoding (deinterlacing) all HDMI modes and the most important - it must be "HDCP 1.2 protocol compliant" to decode encrypted media. From the analog side - quality of tripple DACs and maximum resolution/refresh suported.
 
Last edited:

Dean

Expert Member
Joined
Aug 19, 2005
Messages
2,670
You get passive HDMI to DVI converters and you do get DVI to VGA converters. However be careful, not all computers output Analog over the HDMI port. Only if you hava analog will the HDMI-DVI-VGA route work.

If you don't have Analog on your HDMI source you will need an Active HDMI -> VGA dongle such as recommended above. They should not be more than R150.

Not sure where DVI is coming into any of this ;)

Not sure of the source type, apart from it being an HDMI plug.
Thanks for the additional info.
 

Dean

Expert Member
Joined
Aug 19, 2005
Messages
2,670
All HDMI to VGA converters are "active", as HDMI port do not carry analog signals.

Are the same? From the digital part - capable of decoding (deinterlacing) all HDMI modes and the most important - it must be "HDCP 1.2 protocol compliant" to decode encrypted media. From the analog side - quality of tripple DACs and maximum resolution/refresh suported.

Good points; thanks!
 

Pilgrim

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Jul 5, 2006
Messages
3,097
You are correct, I misunderstood when I researched this earlier (have a VGA projector and an HDMI Raspberry Pi at home).

You can connect an HDMI source to a DVI screen as HDMI is compatible with DVI signals. However you cannot connect that DVI to VGA as there are no analog signals.

My mistake. The correct info is that you can convert DVI to VGA only if the graphics card also outputs the analog signals over the DVI port, something that HDMI simply does not do!

Interesting reading up on it again.
 

Dean

Expert Member
Joined
Aug 19, 2005
Messages
2,670
You are correct, I misunderstood when I researched this earlier (have a VGA projector and an HDMI Raspberry Pi at home).

You can connect an HDMI source to a DVI screen as HDMI is compatible with DVI signals. However you cannot connect that DVI to VGA as there are no analog signals.

My mistake. The correct info is that you can convert DVI to VGA only if the graphics card also outputs the analog signals over the DVI port, something that HDMI simply does not do!

Interesting reading up on it again.

Thanks for the update, and the insight.
 

sajunky

Honorary Master
Joined
Nov 1, 2010
Messages
13,124
The correct info is that you can convert DVI to VGA only if the graphics card also outputs the analog signals over the DVI port
Your DVI to VGA converter was a cheapo - passive.
Active converter will use DVI digital signals, it will work on any graphics card.
 

Pilgrim

Wugger
Joined
Jul 5, 2006
Messages
3,097
Your DVI to VGA converter was a cheapo - passive.
Active converter will use DVI digital signals, it will work on any graphics card.

That is correct, however most older generation computers graphics cards did output analog over the dvi port too. I never had trouble plugging my VGA monitor into the DVI port (with a cable with two different ends, or via a converter).

It only became a problem with HDMI devices. Sad thing is the HDMI to VGA active converter I tried broke after a few minutes! Stupid thing, thankfully Takealot have a great return policy :)
 
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