[Super J]

I would like to build a Bantam DAC and an mini3 headphone amp in the same enclosure. I would also like to have selectable inputs and outputs, so that either component could be used individually. The DAC would be powered by USB and the mini by a wall wart.

Are there any interference problems I could run into?

 

[Juaquin]

You've just described the Carrie. Of course, you'll have to do your own input/output selection.

Carrie USB-Powered Headphone Amplifier - Head-Fi: Covering Headphones, Earphones and Portable Audio

 

[cobaltmute]

Not quite a Carrie - the Mini^3 is wall wart powered.

I don't see any reason why it can't be done.

 

[Super J]

I like the idea of the Carrie, but I would like to be able to use each device separately as well.

 

[mugdecoffee]

I think you could use a switched input jack so that the mini3 (or Carrie) would only use the bantam when there isn't anything plugged into the input jack. For the bantam output you could then just add a second output jack or work in a DPDT switch to select between the two but I don't think there'd be much of a downside to always running the bantam through the mini3.

 

[Juaquin]

Why power the mini by wallwart when you can use the USB supply that's already there? You could also use that USB 5V -> 9V adapter that fits into a standard 9V spot (designed for use in the mini3), that way you can remove the adapter and insert a regular 9V if you wanted to use the Mini3 separately. Someone here did a run of boards for that and I can't remember who its was and I can't find the thread. Apologies to that person, hopefully someone else knows what I'm talking about.

 

[Super J]

I didn't realize I could power both the DAC and amp with the usb power. I have seen the usb adapter that fits into the mini's 9v spot.

 

[cobaltmute]

http://www.head-fi.org/forums/f6/ic-...supply-416347/

 

[CodeToad]

You'll get 11 volts to swing with on the wallwart.

 

[Juaquin]

Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif http://www.head-fi.org/forums/f6/ic-...supply-416347/

Yes, that one! Thanks. Apologies to Nemo de Monet for forgetting that.

If you're worried about swing you can configure the Carrie or the modular power supply for up to 24V (I believe that is the highest voltage DCP available), depending on the current required. A wallwart is fine but the USB supply may be more convenient.

 

[Super J]

How would I tap into the USB power on the DAC to power the Mini?

 

[Juaquin]

Which DAC? Just figure out where the 5V and GND come in and solder a wire there. Then connect that to the power inputs of the Carrie or the modular supply.

Here's a picture of a Bantam hooked up to the Carrie.
(from joneeboi)

 

[Super J]

Most likely the Bantam. I didn't know it was that easy. Thanks.