ectomort

There's a very good chance that you're right, but control signals must get passed from the head unit to the tape module. When pressed, various buttons on the head unit (and the buttons on the steering wheel) have to send commands to the tape unit to perform the action (e.g. to fast forward) somehow. (Perhaps via the digital bus as you suggest.)

OverLOAD

pretty true, but there's what, 6 buttons on the steering wheel just for the audio controls? If there was an analog conneciton, it would have to use at least seven wires to work..

I'm pretty confident that this radio is a CAN bus based system. This means that the audio controls are probably all bus based. However within the tape module, they are probably passed as an encoded digital signal between the different modules. The Audio is probably one of the few things that's analog in the module connector.

I've had quite a few interesting experiences with the tape module, such as instantaneous muting of my aux in if the tape has an error (like it thinking there's a tape problem), such as detecting different speeds on the spool reel and the fixed rate spooler (next to the pickup head). So It's got to be sending bus based messages to the main head unit to mute the sound.

However, to be able to create a digital bus transaction card, which could communicate with the radio, in place of the tape module would be very nice, I just think that probably only FMS Audio have the right information to do it without spending 500 hours trying to analyze the bus protocols, and figuring out which code does what..

OverLOAD

Tamas

iTrader: (1)

...there is one more thing I'd love to know though.
Your Archos is feeding the tape unit with speaker level signal - what if someone would want to use your method to hook up a line level source instead?
The reason I'm asking is that I want to hook up a different hard drive-based player and that has RCA line outputs (non-amplified). Would this method provide still sufficient volume or would it be too low?

Thanks for all the work

OverLOAD

RCA's? Hmm.. Is it the same headphone Jack? That's all I'm using from the archos.. You should just be able to use the headphone jack if the RCA line out is too low.. a pre-amp line-out is pretty different from most line-outs.. from what I remember, most RCA out's are the same as headphone outs.. variable volume.. it should work, but as long as you have a headphone jack, you should be fine.

OverLOAD

Tamas

iTrader: (1)

No, it's not the same as the headphone jack. It's the regular line-out-type red/white plug pair. However, there IS some volume control in the player... so I guess I need to check the documentation as for what signal level it actually produces. I doubt it would be the same amplified phone jack level like the Archos is.
One thing I know is that the signal level this jukebox is issuing is comparable to that of a regular car CD-changer - because in my current car, it is hooked up to the CD-changer input of the head unit and it works fine. Essentially, it is currently behaving like a regular CD changer, as far as the head unit is concerned.
So I suppose I might get problems when even the amplified signal of the Archos produces a little bit less volume than the radio stations. Or not?

OverLOAD

Tamas,

I'm not 100% sure what you'll run into, but my Archos does seem loud enough, but if I turn it up too high, I get nasty sounding clipping at the pre-amp in the tape module (theory..) I can turn the volume up much louder with the archos than a tape would play, but to do it cleanly with no chance of clipping for all my music, I leave it lower for some songs than others.

Why not just use the headphone out plug? The RCA-outs should work too.. The archos can only output somewhere around 400 mW to the headphones, so that's not a whole lot of volume. What kind of mp3 player have you got?

OverLOAD

Tamas

iTrader: (1)

It's a Neo car MP3 player.
It does not have a headphone jack since it is built specifically for car- or home stereo use. Attaches to the head unit like a regular car CD changer.
I see that recently, they started to sell an AUX adapter for it too (which I don't have), but according to their list, it's not compatible with Mazda units anyway.
So it seems the only option I have is to hack the tape unit like you did.
Actually, reading your post, it looks like in case you turn up the volume on the Archos too much, it overloads the tape unit - so I have some hope that the signal the Neo produces will be sufficient with this hack. What do you think? I don't have too much understanding about electronics :D

Thanks for your time.

OverLOAD

It's worth trying, at the least. If it doesn't work well enough, you can always consider another mp3 player?

The RCA line level out is usually a reasonable signal strength. As long as you can adjust the volume out in the Neo, it should be able to be tuned for the tape pre-amp.

OverLOAD

djmn

Great Job! I've been looking for exactly something like this, but was a little too scared to try it myself...I just have 2 quick questions...
1) I have a Mazda6 with the Bose setup. I assume since it's the same cassette adapter for the RX8 this mod will work in a 6/Bose setup?
2) Can I use the ministereo plug output from the Delphi SkyFi XM radio unit as a source or would it be too low of an audio output?
Thanks again.

OverLOAD

djmn:

1. Yes, the guys in the mazda shop who sold me this unit said that the module part number for the RX-8 and the 6 are the same. The only difference is the faceplate. If you do the same thing to the module, it should work the same way...

2. Maybe. It's very likely that it will work. Make sure to use a shielded cable from the tape module (and ground it on the chassis of the module). It will almost certainly produce some level audio.. but if it's too high, there'll be nasty clipping sounds, and too low, and you won't hear anything and/or the noise level will be too high.

If the SkyFi XM unit has a volume, or level adjustment for the output, you should be able to adjust it to a satisfactory level.

OverLOAD

djmn

Thanks for the info overLOAD, I have one more strange question.
Would the cassette module work without the front "trim" piece attached?
Since I'm going to be doing the mod to it and I have no other use for cassettes, I want to be able to "hide" the cassette module behind the orginal faceplate of the headunit.
I assume it would need to "recognize" the electronics (eject button, FF, etc.) the front piece provides, but maybe not.
Any thoughts?
Thanks

OverLOAD

Yup, you can do that. I've removed the tape dash panel from the tape module (while running) and had no problem, except it was a little tricky getting the tape cover back on with the dummy tape in the unit (I had to hold the tape door open while I popped it back in).

I can't see why you couldn't permanently use the blank face plate, other than preventing yourself from actually using a tape if you happened across one. I'm not sure if the blank cover will fit, but it should. I didn't try since I'd have to pull the unit out of the dash to get it back out (or use some string?)..

It's a neat idea to cover it back up, stealth mode.. It'll work just fine..

djmn

Great...I'll give it a try in "stealth mode". I'll let you know how it goes.
Here's a couple of follow up questions:
1) Since it doesn't need the front panel to work and I'm going to hide it behind the original faceplate, would I even need to buy the front panel at all. I can get the cassette module for around $140, but then they charge another $62 for the front panel! Is this how you had to buy yours overLOAD?
Or am I totally off base and the $140 includes the front panel and the $62 would be for a new faceplate with the hole cut out for the cassette?
If I was to get just the cassette module would I be able to manually eject the dummy tape if I ever needed to?
2) As for the dummy tape, I'm not quite sure exactly what I need. You mentioned that if you use just a blank tape with the tape removed you'll get a thread error from the tape module. Can I just use one of those simple cassette adapters for cd players and stuff and just cut off the cord to it, or will I need to remove something else from it so that it doesn't come in contact with the play head?
Thanks again

OverLOAD

You can buy the module from the service department without the faceplate, and it is much cheaper... no problem.. I only bought it since i might possibly want to use an actual tape, and I wasn't sure this hack would work at the beginning, and would have used the oldschool tape adapter the conventional way had I failed..


You can also buy one of the cheapest tape deck adapters (the normal headphone jack type..) you can find, cut the wire, and carefully open it up and remove the tape play mechanism (reduces the noise level a little more), and put it back together and make sure that it still has the tape speed wheel control gears working in it, you'll be set..

Don't forget that shielded AUX in cable, and try to keep it as short as you comfortably can.. (I think about 36" is lots)..


Cheers

OverLOAD

djmn

overLOAD -
Just got the cassette module and I'm going to be doing this mod this weekend. I bought a 16' Sheilded Miniplug headphone extension that I plan on cutting off around 4' and using. You mentioned to be sure and ground it to the chasis of the cassette module.
Looking at your mod, your extension cable has 3 wires (left, right, and return/ground). You have the black wire grounded to the PCB point. ...Is the shielded Miniplug extension going to have a 4th wire that i'll ground to the chasis, or am I to NOT solder the ground wire to the PCB like you did but ground it to the chasis?
Thanks

OverLOAD

Yes, the miniplug connector will have 3 plastic coated wires, you can figure out which is signal left, right and ground, and it will also have another wire which will probably be wrapping around the other three, or it will have a sort of anti-static bag type plastic wrapped around another bare wire, encasing the three inner wires. The 3 wires with plastic coating on them go to the locations I described, and the one ground wire should be soldered anywhere inside the chassis to sheet metal cage. Try to use a location that is well connected to the chassis.

Optionally, you could use twisted wire pairs instead of shielding.. but that's a different story. cat 5e ethernet cable works well, but I don't have any experience using it in this application.

I also opened up my tape module on sunday, and pulled the small ribbon cable off of the 'Amp EQ board' PCB in the tape module. This substantially reduced my noise floor (made it sound better), but also prevents me from using a real casette tape (seems like less of an issue daily..)

I've been using it every day for the last 3 weeks, and I love it. I have an Archos MP3 jukebox, which has been loaded with the rockbox firmware from http://rockbox.haxx.se . It is connected to a DC to DC converter which is plugged into the rear ACC power port, and automatically powers up and starts playing withing about 7 seconds..

OverLOAD

djmn

overLOAD-
Once again, excellent info.
These should be my last questions, I swear!
1) Is the "Amp EQ Board" and the ribbon cable you pulled off marked or easily recognized? Is it shown in any of your pictures? I'd definitly want to do that to mine also if it increases the sound quality. Just wanna make sure I pull the right ribbon.
2) I hate to sound ignorant, but you said to pull the tape play mechanism out of the cassette adapter. I assume this is the silver playhead piece that makes contact with the actual players playhead?
Keep up the good work, and be sure to update us on any other improvement mods you might make to it.
Thanks

djmn

Ok, I lied...
Also, when you say "pulled" the ribbon off, can I just cut it off or do I need to de-solder it out?
thanks

NineT4

This should be a simple enough question. Where do you start, to take the dash apart to get to the components? I don't have tape deck, nor do I ever plan on getting one, mostly I am looking for a way to integrate my handsfree cell kit with the dash a little better. Think if I take it apart to see what it behind it, I will be able to do a semi-permanent install.

So, where do I start?

OverLOAD

djmn,
The ribbon cable sits in a little push clip. You can just pull it out, and it drops the noise floor. If you want to put everything back, you can just plug it back in.

NineT4,
but the tape deck, and do the mod. otherwise, if you're really adventurous, and want to try hacking the head unit, go ahead, pull it and start taking pictures of the PCB's. You could probably hack into both the CD or the Radio but I'd hack into the CD if given a choice, since you won't get radio static, but you'd definately need to burn a special 'silent' CD to make it work. So far, I think the tape mod is as easy as it gets.


OverLOAD

djmn

overLOAD -
I finally got a chance to cut one end off of the shielded 1/8 mini-stereo extension cable that I got. It had 3 wire's wrapped in a thin tin foil. There was a red, black, and bare wire. The red wire was the tip of the plug, black was the middle. So according to your diagram, I wanna solder the black wire to the right channel, red to the left and the bare wire to the return/ground point. correct?
You also said to solder the "shielded wire" to the chasis. It's not really a wire, but should I solder the foil wrap to the chasis?
Why didn't you have to do this for your install? It seems like it should be the same procedure whether its a standard plug or the 1/8" plug.

Also, is it the playhead piece I wanna remove from dummy tape so that the only thing still in it is the tape spinning mechanism?

Thanks in advance

OverLOAD

In my install, I didn't have shielded wire, so you don't see the wire wrap...

That sounds like unusual shielded wire.. The extra ground pin should leave 3 colored wires, plus a bare wire..

You've got a stereo shielded headphone jack right? The shielding is integrated into the grounding on your cable. You should be able to connect it exactly as you described. The shielding is going right to the ground throughout the length of the wire. Some shielded wires will have an extra wire just for the shielding, some will integrate it with the return signal.

This shouldn't pose any problem. You could connect the ground wire to the same location as the signal return.. Just make sure that if there is exposed wire, you cover it with shrink wrap tubing to prevent it from shorting against anything inside the circuit board.

And yup, you can pull the dummy casette head out of the tape adapter, but if you pull the small ribbon cable out of the holder on the underside of the amp eq board, that won't make any difference, so it's probably not worth the effort at that point... The fixed speed spinning mechanism is a critical component, and must stay.


Looking forward to hearing how it works out for you,

OverLOAD

djmn

overLOAD -
It's was a standard 1/8 stereo male miniplug to 1/8 stereo male miniplug extension cable from Radio Shack.
So what it sounds like is that the foil wrap is the shielding, but since the ground wire is bare that two are in essence one wire. So I'll attach everything the same way you did, and attach the one bare wire (which is both the ground/return and the shielding to the point on the pcb that you did. Correct?
Or should I be looking somewhere else for a better/correctly shielded cable?
Thanks again

OverLOAD

Do the first thing

Connect it up the same way I did.. It should sound just fine..

OverLOAD

RotorMotor

OverLOAD:

Awesome how-to bro! Quick question: do you see any reason that this setup wouldn't work with RCA as opposed to headphone jacks? I know next to nothing about electronics, but I have some so-so soldering skills and I can follow directions damn well... :p

I'd like RCA though so I could hook up a beefier MP3 player.