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

[mopar300m]

I just got a 680 and I'm definitely going to add a line in. It seems very straightforward but i have a few questions before I start. There are no decoupling capacitors on the input, are there some further down the circuit? My next question concerns input impedance. Reading the previous posts it seems like a low impedance headphone source gives great results. How does the line input deal with a higher impedance source, like a line output on a CD player?

This is unrelated to the line in mod. I noticed a pair of CA4066 IC's that I assume are for source switching. These chips are known to add a significant about of distortion to the switched signal. Maxim makes a new version with much better specs, however there are some issues with compatibility. Has anyone tried swapping these chips?

 

[Shortstuff]

SURE this is an OLDE' post so I have to ADD/ Chime in,,, I have an RX DT690 I got from a salvage pile....
CD player does NOT read/play but the radio is a cranker! Only thing is a downfall,, NO balance adjustment on this box its bassy, and has great high notes... It has a 4 band EQ (weird) with an independant Bass knob but does the job well!!

 

[jimmyjimmy19702010]

Hi Guys,

I've had some people requesting me to re-post the original photos in this thread but they're long lost.

I've just completed another line-in mod for the Panasonic RX-DT680 for a local member. I've taken the opportunity to take some fresh pictures during the process to replace the previously deleted original photos. The colours of the wiring and the type of RCA input panel has been updated to reflect the parts I’m now using.

James......

 

[BoomboxLover48]

Hi Guys,

I've had some people requesting me to re-post the original photos in this thread but they're long lost.

I've just completed another line-in mod for the Panasonic RX-DT680 for a local member. I've taken the opportunity to take some fresh pictures during the process to replace the previously deleted original photos. The colours of the wiring and the type of RCA input panel has been updated to reflect the parts I’m now using.

James......

Hi James, They are all here.... I don't see anything missing here now ~Royce

 

[jimmyjimmy19702010]

Hi Guys,
I've had some people requesting me to re-post the original photos in this thread but they're long lost.
I've just completed another line-in mod for the Panasonic RX-DT680 for a local member. I've taken the opportunity to take some fresh pictures during the process to replace the previously deleted original photos. The colours of the wiring and the type of RCA input panel has been updated to reflect the parts I’m now using.
James......

Hi James, They are all here.... I don't see anything missing here now ~Royce

Hi Royce, I inserted the new pics into the 1st post so they’re all new pics and the text has been revised also.

James.....

 

[paul2000]

Hey mate, g'day from WA...just wanted to say cheers for the walkthrough. I knew this mod existed but was too lazy so was just using the data cd and CD out line in hack. Totally worth doing - Massive difference in volume , at least fivefold. would not be out of place hooked up to a TV for movies or gaming.

I love this unit - Back in 1991 i saved up my hard earned from my part time job and added birthday / christmas cash and bought the 680 brand new when i was 11 years old. It was around $500 if i recall- a lot of coin for a young fella even without inflation. It has pretty much always been in use since - probably the best value purchase ive ever made - most recently as a kitchen/backroom radio.

Ive had so many good times with this unit - its been with me through every music phase ive been through, as well as a TV sound system for a few years. The mod has sparked my interest in it yet again - im now thinking of rigging a rechargeable 7AH SLA motorbike battery to really trick it out!

Anyone out there who comes across this unit on the cheap, dont hesitate. After nearly 30 years of thrashing, the CD / radio / all buttons / RC work perfect. One Tape deck works ok, one has seized up, but im pretty sure if i ripped them apart and oiled them up theyd be fine too.

Thanks again mate

 

[jimmyjimmy19702010]

Nice work and congrats on completing the mod. It’s about time your CD player had a break!

Enjoy,

James.....’

 

[BoomboxLover48]

James is AWESOME!

I am watching AO and was thinking of our brothers from AU.

 

[nerkus1]

Hello guys,

Joined this forum, because I love Panasonic boomboxes from 90's. Now I have RX-CT980 and just purchased RX-DT670. Unfortunately, it doesn't have a line in. So I tried to do according to this mod for DT680, and worked out

Actually, I soldered audio cable with 3,5mm jack on the other side and connected it to the bluetooth module.

Everything is working great, just equalizer is not making any influence while I am streaming music from PC or Android?
Is it the same on your moded Panys ??



P.S. Greetings from Lithuania!

 

[jimmyjimmy19702010]

Hello guys,

Joined this forum, because I love Panasonic boomboxes from 90's. Now I have RX-CT980 and just purchased RX-DT670. Unfortunately, it doesn't have a line in. So I tried to do according to this mod for DT680, and worked out

Actually, I soldered audio cable with 3,5mm jack on the other side and connected it to the bluetooth module.

Everything is working great, just equalizer is not making any influence while I am streaming music from PC or Android?
Is it the same on your moded
P.S. Greetings from Lithuania!

The Panny equaliser isn’t working whilst using your line-in? Hmm, if that’s the case, it sounds like your unit has an issue that doesn’t sound related to your mod.

 

[nerkus1]

It is working in stereo, bass is good and so on, but equalizer doesn't work. Balance control is ok. I am using some additional equalizers, like on spotify. Maybe I made mistake while soldering?
But it does work when I'm using radio or cd.

 

[jimmyjimmy19702010]

It is working in stereo, bass is good and so on, but equalizer doesn't work. Balance control is ok. I am using some additional equalizers, like on spotify. Maybe I made mistake while soldering?
But it does work when I'm using radio or cd.

Definitely something wrong here. The mod only taps into the tape circuit and has no interaction with the equaliser circuitry!?

 

[nerkus1]

I'll try to check the wires once again.
Thanks jimmyjimmy19702010 for your help !

 

[nerkus1]

It appears that I connected my aux cable to the line out instead of line in. I had to solder to the contacts 4 and 6. When I changed it, equalizer is working
RX-DT670 does have same W301 contacts, but it's slightly different way to tap into the tape circuit.

 

[Fatdog]

Glad you got it sorted and working, nerkus! Now, enjoy it!

 

[Vrece72]

Hi there!
By any chance this will work on a DT610?
It has 12 wires on the w301 connctor. What wires do i need to solder there?
Thanks!

 

[Thedood]

Just installed mod with a 3.5mm connector so I can play an iPhone or Android through it. Sounds great! volume needs to be turned up a little louder than Radio or CD to achieve the same volume. There was a nice recessed hole to locate it and I used a three wire strand from an old PC fan.

 

[DPaignall]

Thanks again to jimmyjimmy, I've just installed the mod and it sounds great with my Axon 7 phone! My eyesight ain't what it was and I'm new to soldering so it was a job and a half for me, but got there in the end - well worth the effort!!

 

[jimmyjimmy19702010]

Thanks again to jimmyjimmy, I've just installed the mod and it sounds great with my Axon 7 phone! My eyesight ain't what it was and I'm new to soldering so it was a job and a half for me, but got there in the end - well worth the effort!!

Nice work!

Yep, after six years this month, my wife and I still use my modded RX-DT680 daily.
Very nice sounding box.

 

[nerkus1]

Hi there!
By any chance this will work on a DT610?
It has 12 wires on the w301 connctor. What wires do i need to solder there?
Thanks!

It should be similar, just need to look at scheme