[tbdoah]

Well, I've been collecting ideas on my Meta, and have come up with the last idea I wanted to impliment in to my amp, three inputs.

Would it be possible to have a 3.5 mm, an RCA, and an optical digital input? I know that it is possible to have both an RCA and a 3.5mm, but has anyone ever put an optical input?

I know that it takes 5 volts to power an toslink reciever/transmitter, and this might be the only problem I could run into.

My main question is, can i impliment a simple slider switch that would select which input to use, that way not wasting power on the optical input all the time?

 

[stereth]

First off, optical in is a digital signal. Mini and RCA are analog signals. You'd need to build something like this to use a digital signal.

And look here for an input-switching project. Yes, you can switch between the inputs, or you could just wire them together as long as you're not going to power both at the same time.

 

[tbdoah]

Thanks for the links, that's just a little bit more than I was expeceting....I knew I'd need a DAC but damn!

I guess that RCA & mini will do fine until I can work on that DAC

.

Actually, it seems feasible, just that's a lot of work to do.

 

[Squalish]

Stereth, what happens if you're going to power both at the same time?

All the mixers I've seen have resistors inline with the signal, can anyone tell me the reason? Something to do with input impedences?

 

[guzzler]

the resistors stabilise the input impedance, yes

as for the DAC board, there has been rumour of aos producing one for the PPA, which would work with the META (i think, anyway!) but if you're spending that on a DAC, you might as well get a PPA as well!

g

 

[rickcr42]

Quote:

All the mixers I've seen have resistors inline with the signal, can anyone tell me the reason? Something to do with input impedences?

sets both impedence and the gain


most mixers (not all) use the the inverting input of the opamp or active device

the active stage "sees" the resistor as a virtual ground hence setting the input Z and in conjunction with the feedback resistor (opamp,not n ch jfet) sets the overall gain