New Posts  All Forums:

Posts by Avro_Arrow

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, the power supply would use the Kubota topology.   The DAC would use the PCM1794a but I'm up for suggestions whether to do SP/DIF or USB and what controller.   Lets get this DIY...
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 crowbar. Open circuit, as the name implies, keeps the headphone jack disconnected until the protection says it is safe to connect it. Crowbar shorts out the output until the...
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
New Posts  All Forums: