[Coco] CoCo2 Composite Boards (update)

[Joe Grubbs]

Awesome! Thanks Ed. I worry about not only protecting those precious original ICs in the CoCo (like the DAC and PIA), but I also have some audio gear with atypically low input impedance, and I don't think the CoCo would appreciate that kind of load if I were ever to connect the audio to anything other than a TV :P



> From: zippster278 at gmail.com
> Date: Sat, 7 Mar 2015 07:50:34 -0600
> To: coco at maltedmedia.com
> Subject: Re: [Coco] CoCo2 Composite Boards (update)
> 
> Joe,
> 
> Both video and audio are AC coupled (cap).  There’s a darlington transistor used
> for amplification and it’s AC coupled both in and out, so it’s definitely buffered.
> 
> Here is the audio portion of the circuit.
> 
> < https://googledrive.com/host/0B1sgl615FlGnVVFhLTRtbVR4R2M/Audio.jpg <https://googledrive.com/host/0B1sgl615FlGnVVFhLTRtbVR4R2M/Audio.jpg>>
> 
> - Ed
> 
> 
> > On Mar 7, 2015, at 5:58 AM, Joe Grubbs <jsgrubbs at hotmail.com> wrote:
> > 
> > Ed, meant to ask you, in this design how is the audio coupled? Resistor and cap, or is there some kind of buffer (simple emitter follower or otherwise) in there?
> > 
> > 
> > --- Original Message ---
> > 
> > From: "Zippster" <zippster278 at gmail.com>
> > Sent: March 6, 2015 8:58 PM
> > To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> > Subject: Re: [Coco] CoCo2 Composite Boards (update)
> > 
> > Yep, that’s what I’ve been using.
> > 
> > - Ed
> > 
> 
> 
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