Jump to content



Photo

* Panasonic RX-DT680 line-in mod for phones/MP3 players*


  • Please log in to reply
56 replies to this topic

#1 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 31 January 2014 - 09:11 PM

Hi Guys,

As mentioned in my recent thread regarding a newly acquired RX-DT680, this morning I've just completed the line in mod that now allows this Panny to become my 'go to' indoor boombox.

I've done the same mod before on my original DT680 and as before, it was a pretty straight forward process.

This mod is suitable for connecting mobile phones/MP3 players. The tape circuit this mod connects to has a higher sensitivity than standard line level line inputs so is not suitable for input sources that do not allow adjustment of the input levels e.g external CD players etc.

This time around, I'm providing a more detailed description of what's involved for anyone out there contemplating the same mod:

1. Remove all the rear screws including the two inside the main battery compartment + the small front screw located behind the volume knob. Open both deck doors and then open the CD cover. Lift up the little tab located at the front of the CD opening and remove the front cover.
Attached File  C9852AF4-CEA4-491E-BAB2-F62E1C954C3D.jpeg   164.32K   21 downloads
2. Remove the 3 screws retaining the bottom button switch 'stick assembly' and push aside.

3. Remove the 6 screws retaining the deck assembly. Lift up the deck assembly just enough to allow you to disconnect the two multi pin connectors. The deck assembly can now be removed. One of the multi pin connectors is slightly longer than the other so they can only be reconnected the right way. :-)

4. Turn the unit around and locate the yellow sticker on the rear. This will be the location of your new RCA inputs.

5. Drill two holes in the approximate left to right center of the yellow sticker. Start out drilling small pilot holes first and then go to a stepped style of drill bit to avoid cracking the rear casing.
Attached File  9A0F139D-3358-46C8-A32A-9B2FEA088752.jpeg   142.29K   20 downloads

I then used a round file to enlarge the holes to the exact size required.
Attached File  D52D85EC-35F7-4A84-8343-685F1D69F151.jpeg   145.73K   15 downloads

6. I used an RCA input panel from Jaycar Electronics. https://www.jaycar.c...socket/p/PS0263
Attached File  918225F5-56E5-4951-8F0A-13F75667C242.png   346.34K   14 downloads
I had to trim around 6mm from each side to allow it to fit in the space allowed.

7. Bridge the ground terminals of both channels of the RCA inputs with wire/solder.
8. Cut 3 pieces of suitable gauge wire to around 10 inches in length each and then solder these wires to the Left and Right channel terminals of the RCA inputs. Next solder a third wire to create the earth.
Attached File  33A5841E-A618-434F-B8A2-577551FFD7B6.jpeg   122.05K   16 downloads

9. Place a little super glue on the RCA input panel before inserting them, together with the 3 attached wires from the front into the holes you've drilled in the rear case.
Attached File  6E072622-9743-4D41-B3DA-6734420E7080.jpeg   66.93K   19 downloads

Then JB Weld around the RCA panel to ensure a solid joint.
Attached File  2200DECE-659A-4C48-972B-A896652F2472.jpeg   89.74K   22 downloads

As you can see, with the decks out of the way, there is plenty of room allowing for easy access. The main board does not have to be removed during the mod.

10. Tin the ends of the 3 wires. Locate the 3 solder pads on the underside of the main board. (W301). The pads are very close together so you will need a fine tip soldering iron to make things easier. With pre-tinned wire tips, you should be able to simply hold the wire against the factory solder blob and apply heat for a clean solder joint.

a: The left most pad is your GROUND. (Black wire).
b: The next pad to the right is your RIGHT channel. (Blue wire)
c: The next one to the right is your LEFT channel. (Yellow wire)
Attached File  28F6B4E6-525A-4509-A1B7-6DA0ABA5CFE3.jpeg   99.3K   25 downloads
Attached File  5B8911B9-CED3-4384-A2E0-884A79108ACF.jpeg   79.26K   20 downloads
11. Ensure you have not bridged the connections whilst soldering. Test for continuity with a multi-meter. If the left and right channel solder pads are accidentally bridged, the 680 line in mod will only operate in mono!

12. Re-assemble in the reverse order.

13. Fire the Panny back up and select 'Tape' mode. Hook up your Iphone/MP3 player and you're away. The sensitivity of the tape circuit is ideal. I normally have the volume of my Iphone set to 1/2 to 2/3 volume for a volume similar to that offered by the CD player in this unit at a given volume setting. I've noticed no RF interference and no hiss at all whilst using the new Line In. :thumbsup:
Attached File  6AF6D05F-289F-43FD-9591-C42A2F5548F3.jpeg   85.71K   20 downloadsAttached File  F26F4521-7D1B-4903-8743-93CC3E62712A.jpeg   98.79K   27 downloads
Attached File  4D9796F0-025D-4F91-A7E7-7CA1396E8122.jpeg   121.92K   18 downloads

The function of the tape decks is completely unaffected by this mod. However, you will have to disconnect the RCA line in cables when playing a tape as leaving them connected will reduce the output level to the speakers.

Total time to complete the mod was around 1.5 hours. Centering, drilling and filing the holes for the RCA inputs is probably the most time consuming part of this mod.

Have fun and good luck with your own mod project.

James.... :-)

#2 oldskool69

oldskool69
  • Moderators
  • 6,791 posts
  • Location'Bama!!! Deep In Da' Heart O' Dixie

Posted 31 January 2014 - 10:44 PM

Fantastic post.  This will be a sticky  Great work and detail! :thumbsup:



#3 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 31 January 2014 - 11:42 PM

Fantastic post.  This will be a sticky  Great work and detail! :thumbsup:

Thanks!  I've been listening to the line in for the past few hours and it sounds great.  The sound quality is similar to the CD player.  Very pleased!!  :thumbsup:

 

James.... :-)



#4 BoomboxLover48

BoomboxLover48
  • Boomus Fidelis
  • 5,227 posts
  • LocationChicago, IL

Posted 01 February 2014 - 08:39 AM

James,

People like you are a credit to this beautiful site! :hooray:

 

We all need to teach others what we've learned. Good Job! :thumbsup:



#5 superlew

superlew
  • Members (SA)
  • 1,087 posts
  • LocationWoburn, MA

Posted 02 February 2014 - 06:02 AM

Looks good. :yes:

A successful Line-In Mod is very rewarding.

I did one on my Mom's DT600, using the Superduper method, through the tuner.

Being a 3-Piece, I used an unswitched 1/8" stereo jack, mounted in the back, and added a very discrete switch under the handle for switching between the tuner and the line-in.

I really should have taken pictures. :dunce:  I'll have to do it the next time I'm in FL.



#6 Sazeus

Sazeus
  • Members (SA)
  • 471 posts
  • LocationMelbourne Australia

Posted 08 February 2014 - 09:12 AM

Thanks for the info!

 

This is one that I need to do.  I don't see myself getting round to it in a hurry though.



#7 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 08 February 2014 - 03:44 PM

Thanks for the info!

 

This is one that I need to do.  I don't see myself getting round to it in a hurry though.

I've been rocking the RX-DT680 like a wild man!!  I had it at a BBQ on Friday night and it was a real hit.  I had various party goers plugging in their MP3 players to the line in to play their favorite tunes! :cool:

 

James..... :-)



#8 goodman

goodman
  • Members (SA)
  • 1,861 posts
  • LocationBulgaria

Posted 20 June 2014 - 02:52 AM

This is very practical mod. You can connect so many devices, now.... ;-)



#9 boomdon

boomdon
  • Members
  • 3 posts

Posted 17 July 2014 - 08:18 AM

:-)


Hey,
I recently did the line-in mod on my Panasonic RX-DT680 and it works with sound coming from both speakers and the balance control working switching from left to right.
One thing I noticed though is that the sound is not in stereo. Sounds like mono coming from each speaker. Followed the mod instructions to the letter.
Can I get some feedback on this ?
Shouldn't I be getting stereo sound with this mod ?
Don Warren

#10 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 17 July 2014 - 02:18 PM

Hey,
I recently did the line-in mod on my Panasonic RX-DT680 and it works with sound coming from both speakers and the balance control working switching from left to right.
One thing I noticed though is that the sound is not in stereo.   Sounds like mono coming from each speaker.  Followed the mod instructions to the letter.
Can I get some feedback on this ? 
Shouldn't I be getting stereo sound with this mod ?
Don Warren

Hi Don,

All 4 radios I have modded are all operating in stereo.

My guess would be a soldering issue where you may have a bridged left/right channel.
The pads a very close together on the circuit board. Check with a multi meter and get back to us. Do you have any pics of your mod?

#11 boomdon

boomdon
  • Members
  • 3 posts

Posted 18 July 2014 - 04:49 PM

Hey Jimmy,

Thanks a bunch for the speedy reply and the advice. Found out indeed the left and right channels were bridge soldered together.
Performed the fix and now I'm getting great sounding stereo out of the unit.
I tip my hat to you, sir !!



#12 riker1068

riker1068
  • Members (SA)
  • 1,069 posts
  • LocationFLORIDA Jacksonville

Posted 03 September 2014 - 12:53 PM

Curious. I was thinking of doing all of my radios with a 3.5mm port. Could I just tap into the line in rca/aux and drill in a port assembly for the 3.5mm Stereo Panel Mount

? In no particular proper language. As I am trying to explain my thought :-D  

 

image 1 as entry view

Attached File  3 5 panel jack.jpg   1.24K   188 downloads

 

Image 2 as rear for wire hook up from line in.

Attached File  3 5 panel jack rear .jpg   1.17K   131 downloads

 

Curious if I can just hook up a jumper? Or would that create feedback?  

 

Figure I'd ask before I try.

 

 



#13 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 03 September 2014 - 10:46 PM

Curious. I was thinking of doing all of my radios with a 3.5mm port. Could I just tap into the line in rca/aux and drill in a port assembly for the 3.5mm Stereo Panel Mount
? In no particular proper language. As I am trying to explain my thought :-D  
 
image 1 as entry view
attachicon.gif3 5 panel jack.jpg
 
Image 2 as rear for wire hook up from line in.
attachicon.gif3 5 panel jack rear .jpg
 
Curious if I can just hook up a jumper? Or would that create feedback?  
 
Figure I'd ask before I try.


There is no reason why you couldn't do exactly what you suggest. I used RCA inputs on this mod so I could use the same cables I use on all my other boxes.

Good luck,

James.... :-)

#14 bujiaemadera

bujiaemadera
  • Members
  • 1 posts

Posted 09 April 2015 - 09:08 AM

thank - gracias por el posy work wanderful , maravilloso !!!!!



#15 Upuaut

Upuaut
  • Members
  • 1 posts

Posted 21 May 2015 - 06:16 AM

Thanks,James.

I am not very clever with my hands but it all worked smooth as butter. Even knowing the number of screws in each case helps a lot :) I will be using a FiiO x3 as a source, however, using the line-out produces a signal which is a bit too strong and tends to give some distortion. But the earphone jack gives a very delicate output especially once the internal amplifier's treble ans bass are set to zero, only using the Panasonic's amplifier with the lavish bass.

 

Thanks again and good luck !



#16 SLiX

SLiX
  • Members
  • 2 posts

Posted 17 August 2015 - 03:01 PM

Just to put the information on this thread:

 

If your are afraid of doing the mod, there is a trick to use the "CD out" as a "Line in" using a blank or data CD: https://boomboxery.c...dt680/?p=297394

 

Yes, it really works !



#17 rci3044

rci3044
  • Members
  • 3 posts
  • LocationIdaho, USA

Posted 19 January 2016 - 10:59 PM

Love the mod provided here.  It has effectively resurrected my 680.  I found an RCA block that had a tab sticking out that would accept a screw.  I used this to mount the RCA's to the back of the box instead of JB Weld!

 

I, too tried using the data CD to play through the RCA outs but I wasn't pleased with the sound.  It just didn't seem full enough.  I am extremely pleased with the sound quality using this line-in RCA mod.



#18 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 19 January 2016 - 11:38 PM

Love the mod provided here.  It has effectively resurrected my 680.  I found an RCA block that had a tab sticking out that would accept a screw.  I used this to mount the RCA's to the back of the box instead of JB Weld!
 
I, too tried using the data CD to play through the RCA outs but I wasn't pleased with the sound.  It just didn't seem full enough.  I am extremely pleased with the sound quality using this line-in RCA mod.

Nicely done rci3044! I've lost count how many people have now successfully added a line in to their RX-DT680s - certainly a lot more than have posted in this thread.

We've got to do all we can to keep these awesome 680s thumping deep into this century!

James....':-)

#19 hardmen

hardmen
  • Members (SA)
  • 1,607 posts
  • LocationItapevi - São Paulo - Brasil

Posted 03 February 2016 - 06:28 PM

Make that mod today with sucsess...

Another satisfied member!!

Thank You!!

Cheers.

#20 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 03 February 2016 - 07:03 PM

Make that mod today with sucsess...
Another satisfied member!!
Thank You!!
Cheers.

Well done Hardman. It's an easy mod for a DIYer!! :-)

#21 hopey

hopey
  • Members (SA)
  • 382 posts
  • LocationMelb AU

Posted 24 March 2016 - 07:48 PM

Great work detailing the whole process. I worked on a sharp boomer with cd disconnect the cd power connector and bridged the cd out RCA eternal connectors. Sweet. So the marked cd out is now line in.

#22 hardmen

hardmen
  • Members (SA)
  • 1,607 posts
  • LocationItapevi - São Paulo - Brasil

Posted 08 April 2016 - 04:10 PM

Well done Hardman. It's an easy mod for a DIYer!! :-)


Jimmy, all I could say is the Panny thumps REAL HARD with that mod!
This put some "famous ones" in a Damm Shame place... ...period!

Thanks again bro!

Cheers.

#23 guyo12345

guyo12345
  • Members
  • 1 posts

Posted 24 April 2016 - 03:07 AM

This was my very first mod and against your recommendation to avoid using tape I spliced and taped my conductors to the wires that lead to those pads as I lack a multi-meter and am not yet comfortable soldering (after removing the twisted wires and connector that leads to the cassette assembly and unwinding them for better access) and used lots of glue gun sticks to secure RCA jacks (on and around the surface making contact then obscene gobs of glue covering the jack sleeves and Panny case interior around them for strength) rather than a block and spliced into the braided shielding for my ground. I started my holes with sharp screws and finished them using a regular drill bit without issue. I then cut back the rubber surrounding the Jacks by about 1/8" to allow them to protrude further through the Panny case for a good connection with my plugs. It seems that either the pad next to ground was left and the next was right or I may have mixed the wires up but it all worked out.

 

Your Mod worked like a charm THANK YOU !



#24 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 24 April 2016 - 04:54 AM

Wow, your 'no solder, tape and hot glue' method sounds like a lot more work than my recommended method!
I'm stoked it's working for you. I had my own 680 at an all day outdoor event today and the line in came in real handy!

Enjoy and well done,

James.... :-)

#25 JoeSun

JoeSun
  • Members
  • 1 posts
  • LocationSweden

Posted 29 April 2016 - 12:44 AM

Thank you so much, James!

 

Who could've thought that a guy from the other side of the globe, not only has the same model of boombox that I got from my father over 20 years ago, but he also did a well needed hack on it. And published it on the Internet.

 

I've never been able to get rid of RX-DT680, despite the fact that I had no real use of it; Cassette player stopped working years ago and all CD's at home are replaced by digital versions. So it has been collecting dust in the garage and that's where I found it the other day and thought "What a shame that it has not a Line In". And then I googled it and ended up here :)

 

I've never soldered before so, yesterday I went shopping a soldering starting kit, a RCA-Panel and a really long screwdriver.

After realizing how small those "connectors" on the motherboard was and how not-so-professional I am with the soldering tool I decided to simply cut off three of the wires that connects the cassette deck (the three that you mentioned of course) to the mainboard. Then I used three terminal blocks ( I think that's what they called) to connect these wires to four (ground 1->2) new ones. Finally soldered the wires to the RCA-Panel (and, yes it was a correct decision to not solder on the Mainboard.. I really need to practice..;-) ).

 

Tested it with my phone and.. Wow! Flawless!

 

Next step will be to connect a Raspberry Pi with Pi Musicbox to it so I can stream Spotify, local music, etc.

 

Once again - Thank you!

 

Best regards

Joel



#26 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 29 April 2016 - 01:55 AM

Thank you so much, James!

Who could've thought that a guy from the other side of the globe, not only has the same model of boombox that I got from my father over 20 years ago, but he also did a well needed hack on it. And published it on the Internet.

I've never been able to get rid of RX-DT680, despite the fact that I had no real use of it; Cassette player stopped working years ago and all CD's at home are replaced by digital versions. So it has been collecting dust in the garage and that's where I found it the other day and thought "What a shame that it has not a Line In". And then I googled it and ended up here :)

I've never soldered before so, yesterday I went shopping a soldering starting kit, a RCA-Panel and a really long screwdriver.
After realizing how small those "connectors" on the motherboard was and how not-so-professional I am with the soldering tool I decided to simply cut off three of the wires that connects the cassette deck (the three that you mentioned of course) to the mainboard. Then I used three terminal blocks ( I think that's what they called) to connect these wires to four (ground 1->2) new ones. Finally soldered the wires to the RCA-Panel (and, yes it was a correct decision to not solder on the Mainboard.. I really need to practice..;-) ).

Tested it with my phone and.. Wow! Flawless!

Next step will be to connect a Raspberry Pi with Pi Musicbox to it so I can stream Spotify, local music, etc.

Once again - Thank you!

Best regards
Joel

Great work Joel!! I use my modded RX-DT680 all the time. You can't beat the wonderful performance from the 680 - particularly the bass!

Modifying the 680 for line in is definately worth the effort!

Enjoy,

James.... :-)

#27 ScareDe2

ScareDe2
  • Members (SA)
  • 119 posts

Posted 28 May 2016 - 06:32 PM

I don't understand why you would modify this boombox, you can simply connect your mp3 player into the mixing mic connection in front, or use a spliter to connect your mp3 player on the back of the dt680 and play a data cd while you play your mp3 player.



#28 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 29 May 2016 - 01:50 AM

I don't understand why you would modify this boombox, you can simply connect your mp3 player into the mixing mic connection in front, or use a spliter to connect your mp3 player on the back of the dt680 and play a data cd while you play your mp3 player.

The reason the mod is suggested is sound quality. The methods you suggest just don't sound as good.

And why churn through D cells burning out an old 26 year old CD player just to listen to an MP3 file?

Try the mod!

James... :-)

#29 ScareDe2

ScareDe2
  • Members (SA)
  • 119 posts

Posted 29 May 2016 - 07:03 PM

ok......... but it does sound very good, if you plug your mp3 player in the mixing mic and use the tape channel you have plenty of extra power that push the boombox to its limit. I just want to be sure every option are carefully tested before deciding to open it and proceed to modifications. If you say it does sound better then all right, it's a good reason.

 

:-P

 

I use low volume with my galaxy player and crank the boombox volume all the way up. I would be pleasantly surprised to get a better sound.



#30 jimmyjimmy19702010

jimmyjimmy19702010
  • Members (SA)
  • 3,544 posts
  • LocationSunny Brisbane, Australia

Posted 29 May 2016 - 07:19 PM

You're having to use low volume on your MP3 player because you're using a circuit that is not designed to handle MP3 player input levels.

I tend to remember the mixing mic input only sending a mono signal to the amp. It's hardly a satisfactory solution.

But hey, if you're happy with mono, then just stick with that - it's all good. :-)