Thread: 2004 VW Jetta GLI CarPC and more

How are you doing the custom bezel for the 8 inch screen? My screen is 10 inches, but that required me cutting the dash and fiberglass/plastic resin filling to build the screen in.

The 8" LCD panel just fits in the DD slot width and fits vertically when I remove the cup holder delete panel.

So, my idea is to mount the LCD against the existing radio cage. I will add a support brace and simply screw the panel directly to the support brace.

The bezel will be made of either carbon fiber or fiberglass. The bezel will be flat and fit within the existing trim and dash with velcro holding it in place.

If I have room I will install the button board in the bezel to have full functionality.

I want a clean install that looks stock.

So, that is the plan but I have a long way to go before I take the monitor apart and verify the dimensions of the panel. I am working from the technical drawings from Xenarc.

Xenarc provided the following link to the latest OSX drivers.

http://home.eeti.com.tw/web20/eGalax...ntelDriver.htm

I will give them a try next week when I get back home.

Finally on my way back home. Can't wait to start wiring everything up on the test bench.

My focus continues to be on the audio interface.

Using a TOSLINK cable and mini adapter, I plugged the mac mini into the Sewell DAC. Then plugged two speakers into the DAC.

It worked accept I had no volume control.

This won't work as I have no receiver to control the volume.

I installed an app called soundflower that gave me volume control.

Now will it work in the car?

I may have to rig it up and give it a try.

couldn't a griffin powermate work with soundflower?

Originally Posted by daclothe

couldn't a griffin powermate work with soundflower?

Yes, the PowerMate works with soundflower.

The digital volume is locked at full volume without soundflower.

Soundflower allows the volume to be reduced.

Today I read all the threads about the Monsoon amp. I also traces the wiring diagram in the service manual.

I verified that there is 6 volts on all the outputs from the radio. L/R F/B +/- when the original head unit is turned on.

I built a test box to inject 5 volts into the negative lead.



Now its time to apply 5 volts and test all the feeds on both sides of the ground loop isolator to make sure I am not throwing 5 volts back to the DAC.

Once that is tested I will connect speakers to the new interface box and see or hear the results.

Then I will move to the car and see if I can indeed power the amp with this configuration.

I am still not sure what to do with the ground from the power circuit.

I applied 5v from the ATX power supply to the negative side of the left speaker.



After testing for voltage I connected the ground loop isolator and behold, no current passed through to the source.

So I plugged the mac mini in to the GLI and the speakers into my interface box.

Everything worked. I did notice that the audio signal was cut down significantly with the GLI installed.

Will this work to power the amp?

It is time to pull the amp and wire in my test box.

I am still not sure how to wire the complete circuit. If I use a voltage regulator the positive and negative leads get connected to the VR and then the output of 5v gets connected to the negative speaker terminal. In my case I am running 5v directly from the ATX power supply. The negative lead is not hooked up. So, is there 5v present on the speaker lead without a ground to complete the circuit?

I test for voltage by completing the circuit to the negative lead from the ATX power supply and of course there is voltage because I complete the circuit.

Yesterday I spent some time testing the difference between using digital audio out and analog audio out on the Mac Mini.

Digital out has the advantage of being digital and if I were to play a DVD in my car, doubtful, I could take advantage of the surround sound. However. The digital out is not designed to have any volume control at the source. The volume control should be handles by the receiver. But. I don't have a receiver and it is imperative that I control the volume at the source (computer). I was able to achieve volume control using a utility called sound flower.

SoundFlower works but I found that it was not consistent enough for me at this stage of my lack of Mac knowledge.

Sewell DAC works great for the right application. It took the digital output from the Mac and processed the signal out to either 2.1 or 5.1. The kicker is that the source has to provide the channel for the sub to work or for 5.1 to work. That means the sub out does not provide a signal unless the mac mini provides a sub channel on the digital out. Same holds true for the 5.1. In essence I would have to wire for 2.1 and the sub may or may not work. In conclusion, the Sewell DAC will not work for my configuration.

Ground Loop Isolator, works as expected but it does cut the output signal in half. Hopefully there is still enough signal to the amp.

My near term plan is to use analog out directly to the amp.

I plan to add a miniDSP DAC in the future which will give me both digital and analog input options. So, I will take another look at digital when I get to that stage. MiniDSP does not have the limitations of the Sewell unit.