Depending on the display used, it could be easy or difficult to source. Most displays use a standard interface protocol but that doesn't stop a manufacturer from using their own custom driver/protocol.

Don't worry, I am willing to do the circuit design and boards. Boards would be put up on OSH Park for public use (thus no group buy needed).   Lets see how much interest there is...

Sounds good. I'm up for a solid state amp and a pcm1794a based DAC.   These would be built with easy to obtain components that anyone can buy, no NDA or bulk buy required.   The amp would be something like the PPA2 (op amp with diamond buffer) but with either two or four channels. Also...

Hey, I have a good idea...Lets design and build something! I have a project if anyone is interested.

Bummer...

I don't have a schematic or the amp in front of me so I have to speculate. Sorry, the 1455 is a dual 555. 180mV is pretty high for a headphone amp. With the protection circuit engaged, you should see nothing at the headphone connector. The relay could be implemented as either open circuit or...

Pin 8 on the protection chip should be the mute timer input. It should go from low (muted) to high (unmuted). You could even drive it high manually.

You should be able to see the 555 time change state after a period of time even if the protection chip does not respond to it. I tried to find a data sheet for the protection chip but information was limited.

Has the amp developed a DC offset? That will trip this circuit. You will have to check before the mute relay.

They come in male and female and various styles. Their use is only limited by your imagination.

It is called an MMCX connector   it is commonly available from sources like Digi-key and mouser

What TomB said...

I would just go with something like this: http://www.digikey.ca/product-detail/en/panasonic-electronic-components/ECQ-E1225KF/EF1225-ND/56392

Hi Fred   Sorry to hear about your troubles. I don't know how I would even cope if I lost my wife, let alone your other troubles. Glad to hear you are on the mend though.   Welcome Back!   Cheers! James

Check out the Doodlebug on Beezar Audio and see if that is what you are looking for.

The player software should make no difference. I use both JetAudio and Foobar2000 without any problem.   The Hiface is a USB High Speed device, I suspect that is where the problem lies. Again, your friend was able to get them to work together, ask them how they had it set up. Are you using...

What sample rate and bit depth are you using? The Doodlebug is a black and white kind of device. Either it works perfectly or it doesn't work at all. The Doodlebug can only support USB full speed operation. High speed is not supported. Due to the complexity of the USB High Speed signal, there...

USB 3 ports are backward compatible with USB 2 Sounds like you have a short in your pupDAC The voltage regulator usually gets only mildly warm, not much above room temperature in normal use. The Doodlebug can protect itself from shorts with an auto reset fuse. Go over all the solder joints...

Yes, it provides complete galvanic isolation. Just make sure your device works at USB full speed, not low speed or high speed.   Edit: I think your interface may be a low speed device. Contact the manufacturer to make sure. The Doodlebug can be hacked to run at USB low speed.

The Doodlebug does nothing on it's own, that is, it is not recognized as a device by the computer. It is locked at USB full speed and will not work with devices at USB low speed or USB high speed. If you have a mouse that runs at USB full speed, it should work, but I think most mice are USB...

No, it doesn't work like that. You have to bias each op-amp output that you want to have in class A. Your not injecting bias into the V- rail, your drawn a small current from the output to the V- rail. Some op-amp benefit more from this than others, your mileage may vary.

If you are lucky you might get away with just replacing the output MOSFETs and resistors. I was not so lucky. I tried to repair a B22 board and it just kept blowing the outputs. I recommend building a new channel.   Good luck!

A cMoy is what a cMoy is. It doesn't really go out of date. Tangent's guide is pretty good at holding your hand through the process. Just read it all the way through. Let us know how it goes!

I want to abide by the thread rules of not saying anything negative, so I will just keep quiet. If the snake oil makes them happy then let them be happy.

Here is my contribution:   317/337 (and family) adjustable regulator tweak.   Replace the voltage setting resistor with a semiconductor.   Typical 317 regulator implementation:   Typically R2 sets the current through R1 and the voltage drop of R1 plus 1.25 volts is the output...