Has anyone had good luck with the aux in stereo mod?

[850oldschool]

I never knew there was lobstering on the Mohawk River. That's amazing!

[wrybread]

Feel free to send any of those lobsters my way! I'm in dungoness crab country, maybe we can work out a trade.

I'm having some trouble finding a bluetooth adaptor that works with the line in mod. I tried this one:

bt1.jpg (11.15 KiB) Viewed 1660 times

https://www.amazon.com/gp/product/B016NUTG5K

And this one:

bgt2.jpg (6.11 KiB) Viewed 1660 times

https://www.amazon.com/gp/product/B004VM1T5S

The first sounds really loud and distorted when played through the car stereo. The second doesn't seem to be distorted but has an unusably low signal. They both sounded bad before I added the resistor too. And both work well with my home stereo.

Interestingly the first sounds loud and distorted with headphones too, and the second sounds really low with headphones. Hmm.

I'm stumped. My suspicion is it's another impedance issue, probably caused by mixing the output from the tape deck with my phone's output.

I don't imagine anyone has a theory?

Also this day in Volvo history for me: modified the front cigarette lighter socket so it's always on, regardless of key position. Makes phone charging much easier. Let me know if anyone is interested about hearing how to do this easy mod.

[xanthefin]

Best thing was when i ended up with locally bought AUX to Bluetooth dongle and i checked after long time usage that it sounded a bit dull why so..

Chip manufacturer itself says "Bluetooth® audio platform -- for entry level to mid-range audio devices".


Oh no.


P.S.
If someone finds easier i copy here too.
I wrote in my thread about cassette mod which has dummy cassette bypass wiring so no need cassette and only bottom plate to open to do the mod. I wrote this down when i was fixing the mod.

But gonna do totally different way soon.. as this mod does not work well on phones which does detect the impedance of headphones instead of physical switch in the port.

[wrybread]

Wow @xanthefin, that's great. Is that an sc-815 or 816?

For the impedance issue, could you simply put a 47 ohm resistor or similar between R and ground?

[xanthefin]

Wow @xanthefin, that's great. Is that an sc-815 or 816?

For the impedance issue, could you simply put a 47 ohm resistor or similar between R and ground?

Someones has been thinking more than me and suggested 100k ohm resistors between channel(L & R) and GND to activate it which sounded more like it... To be honest it could be easy just add in there at bottom those resistors between channels and GND. I haven't tried myself but as saying DC resistance is not the same thats why.

[xanthefin]

Anyone here done MBUS adapter and got AUX via that?

I noticed there is actually two MBUS lines at the back. Another one is super weak. Can't read with transistor with some amplification without drying it down with "current" load.

Then day later i took a oscilloscope to next hole and bingo there is stronger signal which can be read then with adapter but struggling to translate as its pulse width modulation and if i need inverted logic. Blah feels like this gonna take week end from me. I want get easy to replicate arduino build for these and put casette mods to history as i want higher quality AUX. I had enough of it.

[wrybread]

That sure would be great. There's this project, for the HU (Mitsubishi) head units and the melbus protocol:

http://gizmosnack.blogspot.com/2015/11/ ... radio.html

On a side note I made an adaptor for my subwoofer using the "amp" jack on the back. Works great. Here's the pinout:

03-RCA-Diagram.jpg (20.4 KiB) Viewed 1580 times

There are of course also adaptors but inserting thick unstranded wire works well too.

[xanthefin]

That sure would be great. There's this project, for the HU (Mitsubishi) head units:

http://gizmosnack.blogspot.com/2015/11/ ... radio.html

On a side note I made an adaptor for my subwoofer using the "amp" jack on the back. Works great. Here's the pinout:

03-RCA-Diagram.jpg

There are of course also adaptors but inserting thick unstranded wire works well too.

Cool to know future one if ever. I have myself SC-805 so its a bit different protocol. i think now getting there to read it as got cleaner reading with logic analyzer so i don't need keep measuring with oscilloscope all and trying match with arduino to read all bits correctly so can start to have fun.

[wrybread]

I have myself SC-805

I found this for the SC-805 in the comment thread of that link on gizmosnack:

If I remember correctly you can activate aux input by feeding a signal through AMP DIN and pressing TAPE button (A<->B side) 2 or 3 times. It worked on SC-805 and SC-802. It works until you press Eject or disconnect the battery.

Here's a AMP DIN pinout https://i-a.d-cd.net/9326a76s-960.jpg

Input activation video on YT

Would be very interesting if that works.

I wonder if that works for the SC-815/6... That head unit sure looks similar. I've got an RCA wired up to my amp output jack (and input jack?), I'll try it when I'm at my car in an hour or so.

[wrybread]

Made an interesting discovery! If I connect my phone to the amp jack on the back, it plays, no modification necessary. The volume knob on the head unit doesn't affect it though, the volume is entirely by phone. And for example if you're connected to "rear left" and "rear right" it'll only play through the rear speakers.

But max volume on my phone was quieter than when I connect my phone via the line-in jack mod.

Also interestingly it plays the radio or whatever on the head unit while playing the audio from the phone, as a perfect mix. I didn't test for long but it think the signals were mixed perfectly. Could be useful for adding the phone's turn by turn directions or whatever to the radio.

I tried pressing the tape reverse button a bunch of times but I couldn't get that hidden mode to start working on my SC-815.