Stereo/DVD: SC-xxx AUX INPUT HACK

[dmitrij]

Here's the link http://tadfad.com/2007/09/15/volvo-radio-hack/ to how-to guide with pics.
And alternative description here:
http://www.matthewsvolvosite.com/fre...lvo-radio.html

[dmitrij]

Just completed this mod (direct wire, no resistors), so it's time to talk about results.

Well, it's easy to do, but 1) you should be precise with soldering spots;
2) select better 3-wire cable you can find (mine has low quality plastic shield and burned under 25W soldering iron )
3) the sound quality I've got during test isn't the best.... I mean, that annoying "pshhhh" with no signal from any source (mp3 player or Ipod or phone) rests in place after you've launched your Ipod. It can be compared with additional "white noise" from old cassete or vinyl.

So, it works, but I expected more...

If someone here has more technical skills in electronics or have stripped SC-8xx series into pieces, here is some kind of different approach to have AUX from our friends drivind SAABs.
http://jurgar.wordpress.com/2008/07/...-9-5-audio-en/
In 3 words, the man used TELEPHONE MUTE function and different place to solder 3-wire audio jack.

I'm not sure about SC-*xx series radio has this function or similar main plate (lower, big mainboard). But maybe someone could do some research in that direction?

[scutyde]

The SC have a Tel Mute Input (A9) but it is only there to mute the sound, no other input from the the phone.

[dmitrij]

I made an old type mod with my SC-810. The jack was soldered to the plate between cassette desk and main board inline with capacitors to reduce the interference and noise, to L, R, and GND lines. And an old empty cassette used to enable the input from that source. The result is awful: the volume level is low, the noise "psh" still there. So I stopped with that cause it didn't work for me.
You know, I didn't find any pics from bobbych about short pins to bypass the check of "cassette in", that's why I had to strip the cassette.

[850NL]

Hello,

I try to hack my sc801 but i cant see the photos.

Can anybody else see them.

Greatings nw

[brickman]

So a few months ago I did my SC 815 (?) in a 1998 v70, very easy to do, put a dummy cassette in the deck and closed the door on it, left the motors engaged, but so long as the line has an input before its turned to 'Tape' its golden, sound is fantastic, no intereference under any circumstances, very happy

However, I'm now moving to an SC-901 + 4x100w amp setup, so need to hack the 901.

I've trawled all the volvo forums and have not found a defintive answer to hacking the 901's cassette deck.

I want to jack in on the cassette only as the CD3 changer works 100% and I do use CD's a fair bit. I want to go into the cassette AFTER the dolby processor, although on the 815 I had to go before, which is great, unless the dolby button is pressed, then it sounds flat and hissy.

Attached is a photo of the only circuit board on the cassette deck.



Top left of this board is where the 5 way ribbon from the cassette head meet's the board, there are three connctions to the right of the ribbon, and 2 connections (slightly out of sight) to the left of the ribbon connection. I expect these are... RH/LH forward play + RH/LH reverse play + ground? Jacking into this wouldn't be ideal as the dolby processor will potentially mess it up.

Anyone done this on the SC-901?

[Wolume]

Anyone have any photo connection, where connect run_det ?

[Ger600]

Originally Posted by bobbych

now failing all of this, I have one last plan. Since you need a tape in the deck anyway, I can get one of those adaptors, and insert it into the deck. then just feed the 3.5mm jack out of the rear of the unit, instead of out the front!

Why o why did i not think of this? Thanks guys i finally did my own sc 805, but man i laughed when i saw your fall back plan bob because it's the first thing i would have done lol. Now that's some fine "thinking outside the box"

[jcwacky]

Originally Posted by Ger600

Why o why did i not think of this? Thanks guys i finally did my own sc 805, but man i laughed when i saw your fall back plan bob because it's the first thing i would have done lol. Now that's some fine "thinking outside the box"

True, but you get far superior sound quality using the "hack" as it bypasses the cassette tape heads.

[Volvonijs]

Originally Posted by bobbych

<snip>
Basically, there is a line which uses a voltage to tell the unit that a tape is inserted. This uses a 2V supply which is active when the motor is running. So, i dug around the circuit board, and found a donor 2v supply.

...

look at the pic, and you will see the second top connection on the bank is labelled RUN DET. this is the RUN DETECTION line. when no tape is inserted there is Zero volts. When a tape goes in, a live 2v feed is here. So, follow my RED LINE on the pic, and you will see the circled pin. This is another live 2V feed. Simply solder a direct connection between the two.
<snip>

Hi thanks Bobbych for the great howto. I want to do this on my own SC-801 but the pictures are no longer visible. So does anybody have the picture Bobbych is referring to? I am looking for the +2V pickup somewhere on the circuit board and have no possibility to measure it on a bench...

Thanks in advance!