MDS-JE440 optical (TOSLINK) out (project)

[kgallen]

Motivated by the thread on MDS-JE470 optical output mod I thought I'd try similar with my 440, since it uses the same main board from the 640 and thus has all of the component pad-out and traces in place and just needs the components populating and a hole putting in the back panel.

At risk of duplicating an oft-discussed topic, here is mine where I've use surface mount components that fit the existing pads.

Parts list:

(1) IC661: Cliff FCR684205T (OTJ-5) (currently available new in the UK from CPC for £1.36)
(2) L661: 10uH 1210 SMD inductor (in my case I used Bourns CM322522-100K SMD Inductor)
(3) C661: 100nF (0.1uF) 0805 ceramic chip capacitor (I used 0805 but the pads might actually be 0603 size) (I used these). 100nF is very common but don't stress it, anything from about 33nF up to 220nF will do if that's what you can get.
(4) C662: 4.7uF electrolytic capacitor (through-hole) - just from my components box. This is a polarised component, so needs to be inserted into the PCB the correct way around (negative stripe near to IC661, see photos) (Use one that's 10V rated or above, it's on a 3.3V rail so you don't need to use a 50V device as on Sony's schematic). Likewise any part 4.7uF up to 22uF or so will be fine. The PCB is padded with a fairly wide via spacing, so pretty much any sensible electrolytic will fit.
(5) Suitable labeller tapes - when these arrive I will label this socket similar to the factory-fit ones.

You will need a very fine soldering iron tip, some fine solder and some tweezers to mount the SMD parts. You will also need some solder wick (or a solder sucker) to remove the solder which is already reflowed into the holes for the two through-hole components: the 4.7uF cap and the optical transmitter. The hole in the back panel is around 10mm square for the main part and a 3.5mm hole for the screw.

Sorry this 440 looks so tatty - it was bought "cosmetically challenged" as spares-repairs [I think for a tenner], but since I have it working, I might as well use it as my "experimentation machine"!

(In the photos, the 8mm hole you can see in the back panel is my next project when I source all of the components - to try and add Control-A1(II) to this 440. I might fail at this as somehow I might have to convince the machine firmware it's a 640, because it knows it's a 440 at the moment).

[BearBoy]

Nice work Kevin!

[kgallen]

Thanks! More to help others who might want to do the same. I wish I had better metal working tools (and skills!) It turned out I didn’t have any needle files when I came to square off the hole! Doh. 

[M1JWR]

Here is a pic of inside a je470 showing all the unpopulated i/o ports,also shown is the pc link connection for refrence, if you have a 480, from what i remember adding any extra i/o ports is a no go as there is nothing there, wonder if the 470 mainboard has similarities to the higher 770 model.

 

Edited April 14, 2021 by kgallen
Shrunk thumbnail slightly. Click to view full size.

[kgallen]

9 hours ago, M1JWR said:

Here is a pic of inside a je470 showing all the unpopulated i/o ports,also shown is the pc link connection for refrence, if you have a 480, from what i remember adding any extra i/o ports is a no go as there is nothing there, wonder if the 470 mainboard has similarities to the higher 770 model.

This is a relatively late model. They seem to have gone back to through hole components. How bizarre. At this date 2001-ish I'm very surprised surface mount wasn't far cheaper. Far easier for us now though!

[kgallen]

Labelled:

hmm... I do need a gold coloured screw...

[BearBoy]

Very professional looking with the label :-)