SHARP GF 9090 modification

Got a time ago a broken 9090 with dead tape and missing door.
Will pull out the tapedrive, need parts for another one.
But what to do with the rest?



Got this touchscreen MP3 player.
Want to implant it.



Found a door, will make it fitting to close the "hole"





the player will be mounted there



but the question:
How to connect it to the box?
It owns no line in.
Any possibility to connect it at the old tapedrive?
Anybody done something before?
Ideas welcome.

thats going to be cool roman i think somebody did a mod by connecting a line in cord to the wires on the tape head .

JVC Floyd said:

... i think somebody did a mod by connecting a line in cord to the wires on the tape head .

Click to expand...

this is what i would prefer.
But how to connect them?

Norman?

ViennaSound said:

JVC Floyd said:

... i think somebody did a mod by connecting a line in cord to the wires on the tape head .

Click to expand...

this is what i would prefer.
But how to connect them?

Norman?

Click to expand...

roman i think you basically cut the ends off of a pair of rca cables ,then strip the wires and remove the tape playback head and solider the rca wire ends that you stripped onto the wires that were connected to the playback head connecting the + and - wires accordingly ,make sure the cables have enough length to them so you can pull it out to connect it to the new player.

JVC Floyd said:

ViennaSound said:

JVC Floyd said:

... i think somebody did a mod by connecting a line in cord to the wires on the tape head .

Click to expand...

this is what i would prefer.
But how to connect them?

Norman?

Click to expand...

roman i think you basically cut the ends off of a pair of rca cables ,then strip the wires and remove the tape playback head and solider the rca wire ends that you stripped onto the wires that were connected to the playback head connecting the + and - wires accordingly ,make sure the cables have enough length to them so you can pull it out to connect it to the new player.

Click to expand...

That's not going to work because the cassette heads connect to a high gain preamplifier (since heads are very low level input devices). Also, the cassette head performs 2 function -- playback and also record. While playback circuitry allows the heads to operate in a capture capacity, accidentally triggering the record could have undesired consequences since it reverses the function and sends an AC signal to the heads....... in this case, the MP3 player since you've cut the wires and put it into the MP3 player. You will probably NOT want this circuit to inject an AC current into your MP3 player.

Instead, you can either insert one of those cassette adapters that you connect to MP3 players or bypass the highlevel inputs internally. Does this thing have phono in? If it does, then you can bypass the phono amp internally, or solder the wires to the inside of the phono jack with some small circuitry. To get sample circuitry, just google.

For me, I think I would still use the tape function for the MP3 but just bypass the tape amp entirely. You do this by tapping into the appropriate location at the tape/radio switch.

Roman: if you are serious -- LMK and I'll find the appropriate spot on that switch to tap into if you want to do it that way. Or like I said, the simplest way is to just use a cassette adapter.

awesome ,ignore what i said .

No Floyd. It makes great intuitive sense -- in to in, out to out. That is the skill that any AV guy learns in a hurry.

Only it's just a little more complicated than that in this case. Tape, phono, line-level, are all input devices fer sure but each has different electrical characteristics. Before meeting up up at the function selector junction, each signal path travels through the appropriate compensating circuitry first. By the time the signal gets to the function selector, then all the signals should be equal. So that is the logical place to tap into.

great now we know, my crap answer was just to lure norm out to give the right one .

JVC Floyd said:

great now we know, my crap answer was just to lure norm out to give the right one .

Click to expand...

Actually Floyd your not 100% wrong because he can still use the head input but just needs to add the cassette adapter as Norm said

well the tape door did not look that bad

baddboybill said:

JVC Floyd said:

great now we know, my crap answer was just to lure norm out to give the right one .

Click to expand...

Actually Floyd your not 100% wrong because he can still use the head input but just needs to add the cassette adapter as Norm said

Click to expand...

The problem is, i want to pull out the complete tapedrive, as i did on the powerplay machine.
But the other one had linein, so no problem

A few more pics.
Switches:


connection possibilitys:




Can i hook it anywhere to the DIN or mic plug?

Roman:

(1) I think fatdog wants your tape counter

(2) If you pull out the entire tape drive, then you'll have an empty spot on the top where the cassette keys used to be, right?
Over here in the US, we don't really use DIN inputs much and my schematic does not show the DIN so I can't comment on that. I did however find on the schematic where the tape circuitry enters the function switch so if you like, that is the place where you would connect your MP3 signal wires. Do you feel comfortable to do this? If yes, I can tell you where. LMK how you want to approach this.

You can pull the deck out and just leave the head in there. I did see it in another post but can't remember which one where they took the parts out of the cassette adapter and attach to head...or you probably should go with Norms idea

All right Roman. Here is what I can suggest to you.

This plan should work if I didn't mess up.

(1) Using a proper 1/8" mini plug cord, connect to your MP3.
(2) The other end of the cord, cut it to length and strip. Ground the shield/ground wire near the signal wires. The switch cover (I'm gonna show you in a sec) should have the housing grounded and you might be able to use that as the signal ground. The two signal wires (L/R) connect to the function (Tape/Radio) switch at the locations shown.
(3) On your existing tape deck -- Before you remove it -- pay attention to which leaf switches closes when you press the play button. One probably turns the motor on. The other one switches the amplifier on. You'll need to determine which is which. An easy way to find out is to try closing the switches manually with a toothpick (or plastic screw driver). Since the switch is live, I suggest not to use metal screw driver or you could accidentally short out the live power wire. Closing one of the swiches should cause the motor to run. The other one should turn on the amplifer. If you turn the volume up all the way, you should be able to hear hiss or other noise through the speakers. Stop. That's the switch we are interested in. Take those two wires and mark them -- you will connect them to a new switch when you remove the old cassette mechanism.
(4) In the vacated HOLE left over by the now removed cassette mechanism, fabricate a plastic plate or something to cover that hole and install a switch labeled MP3-ON or MP3-Power (or whatever you want). You need this switch because when the function switch is at the tape position, it relies on the tape mechanism to supply power to the amp. With the tape deck gone, you will need to rig up a new switch to power on the amp for the MP3 player.
(5) That's it. It should work.

wow, big thanks!
Will try so.

It´s a shame, because i was radio technican.
But this is 16years ago, and such modification i never did.
Maybe because there have no MP3 players exist...

counter goes to bobby!

Let us know how it goes. BTW, if you look at the upper left corner of the image, you will see a grounded signal cable. That cable is grounded to the big fat trace. You can probably ground your signal wire right there too because it looks pretty close.

Remember -- that image only shows you how to get the signal to the proper location. You still need to switch the amp on in order to hear the music since the function switch does not provide power to the amp when in tape mode. Normally, the amp will get power when the PLAY button is depressed. That's why I said you should find which wires on your cassette switches on the amp and make a new switch, maybe next to the MP3 player, or my preference is a nice matching switch on the top since you need to plug that rectangular hole anyhow.