Resolved Chaining Display Adapters? TB -> DVI; DVI -> VGA

[Ledgem]

Greetings all!

I'm in the process of upgrading my early 2008 Macbook Pro to one of the new models. The new models have replaced the DVI output with a Thunderbolt connector. Since I have an older Apple Cinema display that connects by DVI, I'll need to buy a Thunderbolt to DVI adapter.

However, I also use my computer to give presentations, which involves hooking it up to a VGA cable. I have been using Apple's DVI to VGA adapter for that purpose.

So then, here's the question: would I be able to chain display adapters (Thunderbolt to DVI adapter, then linked to my old DVI to VGA adapter)? Or will I need to purchase a Thunderbolt to VGA adapter?

Thank you for the advice!

 

[nitromac]

it will probably work fine. Converters aren't rocket science, so I'm sure they're chainable.

 

[Freyqq]

nope doesn't work

need a mini-dp --> dvi or mini-dp --> vga
it's because dvi is digital and vga is analogue

 

[nitromac]

nope doesn't work

need a mini-dp --> dvi or mini-dp --> vga
it's because dvi is digital and vga is analogue

Aaaaand the DVI-VGA converter converts digital to analog.

The way he's explaining it, it should work fine.

 

[Freyqq]

Aaaaand the DVI-VGA converter converts digital to analog.

The way he's explaining it, it should work fine.

yeah an active converter would work, but a passive adapter would not

 

[Stetrain]

Aaaaand the DVI-VGA converter converts digital to analog.

The way he's explaining it, it should work fine.

Many simple DVI to VGA converters rely on the DVI connector having analog pass-through pins. I don't think that the Mini-Displayport to DVI adapter provides those signals.

 

[spoonie1972]

Many simple DVI to VGA converters rely on the DVI connector having analog pass-through pins. I don't think that the Mini-Displayport to DVI adapter provides those signals.

infact, the female end on this has blockers where the 4 pins would go around the single large spade.

 

[Ledgem]

infact, the female end on this has blockers where the 4 pins would go around the single large spade.

I read a review of one adapter that basically said as much. I'd never noticed it before, but as you say, the DVI to VGA adapter had four tiny pins added whereas a standard DVI cable does not. My Macbook Pro's DVI port has four openings for those pins, but it sounds like the Thunderbolt (mini display port) to DVI adapters do not, even if they're "active" (instead of "passive"). That's disappointing, but at least now I can save on shipping

Thank you all for the advice!

 

[houkouonchi]

Many simple DVI to VGA converters rely on the DVI connector having analog pass-through pins. I don't think that the Mini-Displayport to DVI adapter provides those signals.

This...

It really depends on the type of converter he is using or if its really a converter.

Most people call it a converter but its really just an adapter (and as he said passes through the analog over the analog portion of the DVI port and uses DVI-I connector). The macbook is DVI-D and unless he bought an expensive (probably > $100) and relatively large converter box (not a small little adapter) its not going to work and he will probably need a DP -> DVI and a DP -> VGA adapter.

Op should also be aware of if he will be using high resolution monitors (over 1920x1200) as then he will need the USB powered dual link DVI adapter which is more expensive (cheapest one being $70 from monoprice).

 

[terraphantm]

Depends on if the mDP -> DVI adapter has DVI-I or DVI-D. If it's DVI-D, the typical DVD->VGA adapters won't work. If it's DVI-I, it'd work fine.

 

[Ledgem]

Curiously, I found an adapter that has the four pins needed by my DVI to VGA adapter. It's cheap - $11 from Nippon Labs. I haven't placed any orders yet, but I'll probably go with that one. If it really accepts my old adapter, I'll test it out and see if it works. Based on what has been written here I don't expect it to work, but it's worth a shot.

 

[Ledgem]

Curiously, I found an adapter that has the four pins needed by my DVI to VGA adapter. It's cheap - $11 from Nippon Labs. I haven't placed any orders yet, but I'll probably go with that one. If it really accepts my old adapter, I'll test it out and see if it works. Based on what has been written here I don't expect it to work, but it's worth a shot.

Just to follow-up, the Thunderbolt -> DVI adapter from Nippon Labs can be physically daisy-chained to the DVI -> VGA adapter, but I wasn't able to get any signal to a projector that way. There wasn't any flickering involved, either; just no signal. Go figure, it wouldn't be that cheap or that easy.