Adding line-in to a Sharp GF-8989, and other stuff

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grimep

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Jul 30, 2010
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Hi all, I'm new round here, just been enjoying all the great pics and stories on here, nice work :yes:

Well, I've got a little project to breath some new life into an old GF-8989. This 8989 is a unit of sentimental value- it belonged to my grandparents. I've got memories of being around 10 or 11 years old, reaching up to fiddle with it, playing whatever tape was in and enjoing the sound. It lived just outside the kitchen on a shelf as the kitchen was too small for it. Well, a few years ago I inherited it when my grandad finally passed away, and its been on a shelf ever since. Its had a sheltered life so apart from the odd scratch its in very good cosmetic condition, and just needs a clean. Electronically its ok, its got a very crackly vol pot which i'll either spray with contact cleaner or maybe replace. The tape deck plays more or less OK, but the sound is very muffled, and the left hand channel is almost dead, just a feint sound coming out. So while it would make more sense to get rid of it and get something with a line in already, like an 8989 II, I want to keep this particular unit as it has memories that go back to the early 80s. Also I'm keen that any modification I do has the least impact on the case.

Anyways, arrival of 2nd child means I'm having to downsize my home office and clear out stuff that's been hanging around. So I want to use the 8989 for computer audio, and give it a restoration job at the same time. Given some of the amazing restoration stories Ive seen on here, it can't be that hard right?!

So I'm wondering what the options are. Being a v1 8989 it only has a phones out jack, mix mic in, ext speakers (oldskool spade connectors), a stereo mic input pair with a jack labelled "remote", and a DIN marked Amp, which I presume is out only (I dont have a user guide). I guess the mic inputs only work when the tape transport is playing? Or could they be the answer? The other issue with adding a line-in is power / source select. There's a button that toggles between radio and tape/off. So, to give this unit a line-in, I guess I need to have a 3-way source selector: tape/off, radio and line-in, or a second 2-way. Does anyone know if that's how an 8989-II works?

This could be too big a job for me, I'm not too experienced with electronics, so options are:-

1. use one of those cheap mp3-cassette converters, though I'm not entirely sure how they work, and dont like the idea of the tape transport motor having to turn in order to use one. Anyone got any experience with them? I guess I'd still need to fix the tape player too for this to work?
2. rewire it with the DIN socket going to the radio/tape-off switch so that selecting radio would select the DIN for line-in. Could I do that?? It also would need some small breadboard of components I guess, resistors and whatnot?? It would be a shame to lose radio.
4. do a full job- recondition the tape deck or get it serviced (assuming I can find someone to do it in these days of disposability), mod the case and add a jack or repurpose the DIN, convert the 2 way switch to 3 way, or add a second input selector, and add any necessary electronic components for this new circuit, assuming I can figure out what's needed.
5. put it back in the loft and forget about it :sadno:

Finally, any ideas what the tape deck needs? Ive tried cleaning/demagging the head but it made no difference. I've got a multimeter so I might have a poke around. Oh, and how do I not electrocute myself?!

well, any ideas greatfully received!

just a quick edit to say... thinking about it a cassette adaptor is probably the best bet, but I guess I need the tape head reading and playing correctly, so advice in that department is needed. I suppose I could just disconnect the motor so that there's nothing turning when the adaptor is in use.
 

2steppa

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May 11, 2009
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Hi all, I'm new round here, just been enjoying all the great pics and stories on here, nice work :yes:

DIN marked Amp, which I presume is out only (I dont have a user guide).

use one of those cheap mp3-cassette converters,

put it back in the loft and forget about it :sadno:

Finally, any ideas what the tape deck needs? Ive tried cleaning/demagging the head but it made no difference. I've got a multimeter so I might have a poke around. Oh, and how do I not electrocute myself?!

First and foremost, hello and welcome. :thumbsup:

The DIN on the 8989 is bi-directional and will accept a line-level input, the rub is that rec/play will need to be depressed.

Those MP3 cassette adapters work well, I've tried one on my 8989 and the results were very pleasing.

Perhaps the head azymuth has been tampered with at some point, either that or possibly there's a fractured wire from tape head to pre-amp section.

In order to be safe run the unit on batteries when carrying out test/diagnostic work with case open.

The actual boombox itself is safe as it's a 12-15v supply but the mains power section is hot (230v AC) and EXTREME care should be excercised if you have the mains connected and case open. (Often the mains side is insulated but not always, be safe not sorry!).

DO NOT STICK IT BACK IN THE LOFT!!!!! :nonono:

Good luck, and other members may well have more advice to volunteer. :-) :surf:
 

grimep

New Member
Jul 30, 2010
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Thanks for the reply, yeah, looks like I'll have to give one of those converters a go. Do you think there's an easy way to mod it so there's no need for the transport to turn once you press play? I'm imagining its just a case of disconnecting something. cheers
 

baddboybill

Member (SA)
Jul 14, 2009
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welcome aboard!!! :-D 1st off and this is my opinion, since your grandfather owned this prized procession and its in great shape physically (which it sounds to be ) then you should not ruin the astetics of the bbx. If you want to listen to ipod/cd then you can use the cassette adaptor and nothing will need to be changed. What you should do however is either clean and repair her up or have it done professionally ;-) There are not many of these boomers clean and working 100% out there so its kinda like our job as collectors to save as many as possible :thumbsup:
 

grimep

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Jul 30, 2010
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welcome aboard!!! :-D 1st off and this is my opinion, since your grandfather owned this prized procession and its in great shape physically (which it sounds to be ) then you should not ruin the astetics of the bbx. If you want to listen to ipod/cd then you can use the cassette adaptor and nothing will need to be changed. What you should do however is either clean and repair her up or have it done professionally ;-) There are not many of these boomers clean and working 100% out there so its kinda like our job as collectors to save as many as possible :thumbsup:

Yeah, I agree. oh hang on there's a little feller that says that . . . . :agree: I just thought maybe fitting a line-in might be a common modification, so maybe not such a big deal. The ideal scenario would be this thing as pristine as poss and working as intended, with a line in to make it much more useful in this day and age. But if its so easy with an adaptor, I guess there's no point. Well, I'll open it up, have a fiddle, give it a clean, and when I get completely stuck, seek professional help! I'll probably see if there's some way of disabling the transport so it doesn't need to be actually turning the spindles to work, I wonder if anyone else has done that. Can't wait to get this hooked up, 80s music inc electro and hiphop sounds best through one of these babies :-D
 

foxyloxy

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Oct 20, 2010
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Hi, if you want to play an mp3 thru the 8989, there's another way. If you wire up 2 mono minijacks to the end of the stereo lead from your mp3, you can plug them into the mic sockets. Put in any old cassete - even one with no tape in it, and press Record,Play and Pause, and the box will play your music. It doesn't stop the transport motor, but the Pause button lifts up the pinch wheel so the transport mech won't move. This and the adaptor method are both cheap, so you could try both & see what sounds best..
 

foxyloxy

Member (SA)
Oct 20, 2010
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hi, re line-in to 8989, if the cassette deck electronics are faulty but the radio works, find a friendly audio engineer or electronics person, it is OK to wire an audio source directly to the volume control.. You may be able to hi-jack a stereo socket, like the mix socket if it isn't wired directly to a circuit board, or you may drill the case if there's room for another socket, and wire this socket to the volume control using wires. i realise this is changing the box but it's electrically ok as a line level signal from an mp3 player will not pick up interference.Or you could put an inline stereo jack socket (the kind with a plastic or metal sleeve) in the cassette space, this wouldn't be a major change. If the casette tray doesn't close fully then cut just a little triangle off one corner to let the cable thru.
Can anyone tell me what the MIX socket does, or how you use it ?
 
I say FM Transmitter! You tune to a certain radio station that doesn't have any station coming in, and you set your FM Transmitter to that same station. Plug your iPod or Walkman to that FM Transmitter and Bingo! You got stereo audio coming out of your speakers and you don't have motor spinning or wires cut!

Btw, WELCOME to Boomboxery bro!!!! :breakdance: :breakdance: :breakdance: :breakdance: :breakdance:
 

baddboybill

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Jul 14, 2009
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I say FM Transmitter! You tune to a certain radio station that doesn't have any station coming in, and you set your FM Transmitter to that same station. Plug your iPod or Walkman to that FM Transmitter and Bingo! You got stereo audio coming out of your speakers and you don't have motor spinning or wires cut!

Btw, WELCOME to Boomboxery bro!!!! :breakdance: :breakdance: :breakdance: :breakdance: :breakdance:
I agree and you keep the bbx in original shape :-D
 

blu_fuz

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Jun 3, 2009
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I have a 8989 II you could buy and use the guts for in your 8989. Let me know if you want it. Oh, and mine is fully working ;-) .

 

djetaine

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May 13, 2010
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do it with the DIN connector, fm modulators are sketchy at best and with a mp3 to tape you still have to worry about transport movement anyway. I have wired line in's to a few of my boxes but with an 8989, i would definitely want to keep it in its oem condition. As for the mic input, i dont know specifically about the 8989, but for the most part, mic ins are not line level inputs, therefore its going to to be amped for the mic. you dont want to to plug an mp3 player thats already amped into another amped input, you will introduce distortion.
 

Tam9n

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May 3, 2012
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I just bought a fully working GF8989 I around 25 quid.
This will be the first boombox I have ever bought.. I'm only 18 and have little cash for starting a collection!

Can't wait to receive it, but I'm still lost as to what ways I can connect an mp3 player, the macbook etc up to this box?
Don't wait to take it apart, as I know very little about boombox (for now ;) ).

Cheers! :-)
 

Reli

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Dec 24, 2010
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The DIN on the 8989 is bi-directional and will accept a line-level input, the rub is that rec/play will need to be depressed.

That is what I did. Just buy a 5-pin DIN cable with a headphone jack on the other end for you ipod. Search "din bang" on Ebay.
 

Reli

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Dec 24, 2010
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Yep. Assuming your GF-8989 actually has a DIN input. I think it was only Euro models that did.
 

Tam9n

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May 3, 2012
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Only got the box back from being repaired there.. long story.
Din cable does work.. when play is pressed.. but it's very quiet and not great quality?
 

jimmyjimmy19702010

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May 5, 2012
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Only got the box back from being repaired there.. long story.
Din cable does work.. when play is pressed.. but it's very quiet and not great quality?
That seems to be a common issue with these older units that need a higher input level than is offered by a 3.5mm heaphone jack. :-/ My old Hitachi 9140 has the same issue with it's 5 DIN input - I don't have to press REC but the volume and quality is pretty much useless.

James..... :-)
 

Tam9n

Member (SA)
May 3, 2012
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United Kingdom
Only got the box back from being repaired there.. long story.
Din cable does work.. when play is pressed.. but it's very quiet and not great quality?
That seems to be a common issue with these older units that need a higher input level than is offered by a 3.5mm heaphone jack. :-/ My old Hitachi 9140 has the same issue with it's 5 DIN input - I don't have to press REC but the volume and quality is pretty much useless.

James..... :-)
Cheers James, also encountered a new issue, when it's plugged into the mains, every so often it looses power altogether, and if I wiggle the plug its okay for abit.. then stops again. It can go for hours, or seconds and then stop? Any ideas?
 
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