Hello, I have a problem with a non-working WM-D6 I've just bought. I tested it (with rechargeable batteries first, then with a non-official power plug) how it played back a tape and everything seemed to work fine except the speed. Looking around (and discovering this forum in the process), it looks like the WM-D6C has that problem where somebody plugging an adapter with the wrong polarity will blow a (pretty much) unobtanium IC. However, I might be looking at the circuit diagram in the service manual the wrong way but it seems like the power goes directly to a DC-DC converter so I'm puzzled Yeah looks like I misread the diagram, I see 6V going directly to Q603, IC601 and CP602 in the diagram. Let's go back to square one: does anybody have any clues about what could be wrong with it? Is there any hope of saving the unit? I may be able to fix an easy issue, but anything beyond basic (de)soldering is out of my scope. I've seen a thread of people who are experts in repairing those devices, but I feel like asking first is a good idea. The unit's serial number is 11209. EDIT: I tested how long did it take the device to go through a 90 60-minute tape (well, one side, so 45 30 minutes). 11 minutes, so the speedup is ~3x. I've also added some clarification and the device's serial number in case it helps. EDIT #2: I've compared the playback speed I get while using batteries vs. when using a power cord and they are different. Kinda obvious given the kind of problem I'm having but still worth checking.
Done, I hope she doesn't find it rude to DM her directly out of nowhere. Yeah, I read the ongoing thread about the CX20084 chip and she seemed really knowledgeable.
Hi Jose and welcome to Stereo2go. I have just sent a reply to your DM. If your walkman is a D6 and not a D6C then it will not have the CX20084 chip. A D6 (which is the earlier version, produced between 1982 and 1984) has two headphone sockets and only has Dolby B, not Dolby C. The fast running on a D6 is normally caused by a chemical breakdown on the potted CP602 module and this can be repaired using the method I have written here: Sony WM-D6 Motor runs fast; Repair of CP602 Servo Circuit Unit The other four potted modules will need to be replaced. I have replacements for these available for sale on Ebay. The D6 is well worth restoring as, to my mind, it produces a fuller and more detailed sound than the D6C.
Thanks, I've already replied back to you. Yes, my walkman is a WM-D6 so there is hope for a feasible fix! I'll read the post you linked and try to make the appropriate checks to verify the issue. I will most likely come back to you if (when) I require your services. As for the sound, I've read other people say the same several times. It's a nice-looking unit that even after 30 years and having a defect like this still feels robust and capable of a lot more. It would be a shame leaving it in such a sorry state, it deserves better.
Deb64 serviced my D6 last year, and today, 40 years after I bought it, my D6 works as nicely as it did when it was new! (My D6 had the same problem yours has.)
That sounds amazing! I hope mine finds salvation too. You're going to laugh at me but being young enough to grow up in the era of frenetic consumerism, having a device which can deliver such quality after 40 years is unbelievable to me. In fact, some time ago I had the same realization while digitizing my mom's camcorder videos. It's a Sony TRV-12E MiniDV device, so it has a tape mechanism. The device is almost 25 years old, and it has been sitting in a drawer untouched for at least 15 years. Most tapes are almost 20 years old too. And the device just... did its job! I'm not used to tech being useful for more than, dunno, 5 years? These devices prove me wrong and I admire them. I talk too much, what were we discussing? Oh yes the walkman! I've tried recording a song from my computer onto a tape to check everything else. If the defect makes the tape go faster, recording at that speed should "work" (even without the circuit tuning the speed to make it perfect I assume). Used a cheap cable a friend lent me, a decent tape, some crappy headphones and some Spotify music (so the setup is far from ideal but hey, it's a silly test after all). All the buttons and jacks worked as they should, also the VU meter (which is gorgeous!) so the test was positive. I had a lot of fun doing all of this haha.
You're not the first person to mention that, I have heard they play back better but need the Caps done on them...what do you personally think it is that makes them better?
The sound quality from the WM-D6 compares well with early WM-D6C units with 5 digit serial numbers because these units share a high quality amorphous "pointy" head and a PCB which predates surface mount design (SMD) and use many more through the hole components on the circuit boards compared to later D6C's which had increased use of IC's on wave soldered mass produced circuit boards. SMD was breakthrough technology and widely used in the 80's within the electronics industry which allowed rapid manufacturing of circuit boards at lower cost per unit. However many enthusiasts agree the audio quality, although good, was not as good as early non SMD WM-D6C Walkman.
Interesting... I can tell the difference between the SMD and Thru hole boards, but cant really tell between the pointed head and (early) non pointed head, though admittedly I have not used my early pointed head machines nearly as much as my late 80s through hole unit... I should finish restoring them
I think the D6 sounds better than the D6C because Sony used high quality components in its manufacture. The head is a high quality sendust head, which is very resistant to wear. I guess the Dolby chips used produce a better sound. Also the line out signal is taken directly from the Dolby chip (via a capacitor and a couple of resistors) not via a separate line amplifier op-amp like the D6C. The electrolytic capacitors used on the D6 are very good quality and it is very rare to find one which has failed. I have worked with, and listened to, all of the versions of the D6C and I find little difference between them for sound quality. What is noticeable, however, is that Sony appeared to be looking to reduce production costs later in the series. The later D6C use permalloy heads, which are more prone to wear with heavy use. While the SMD models still sound very good, they are more prone to failures of the electrolytic capacitors used in them. However, the lack of potted sub-boards makes them more reliable in other ways.
While we're on the subject of the WM-D6, I checked the record/play frequency response of my 40 year-old unit (after repair by Deb64), and got the excellent results shown in the graph below. By the way, the rolloff at the low and the high end occurs on the input side of the D6's electronics (i.e. before being recorded onto the tape). The rolloff at the high end is very steep due to an always-on 19 KHz filter that knocks out any pilot tone that may be present while recording FM stereo radio broadcasts. (Too bad the FM multiplex filter can't be turned off, otherwise the D6 would have a flatter, more extended high end recording capability.) Wow & flutter averages 0.04% (RMS, DIN weighted). Speed accuracy is spot on. I am using rechargeable Lithium Ion AA batteries as the power source for my D6 (NOT recommended for the WM-D6C due to their 1.55 volt output). On a full charge, I recorded on metal tape with Dolby B for 2 hours, then I played back type II and IV tapes with Dolby, listening via headphones for 8 hours -- and the batteries had still not run down! Note: These lithium ion batteries maintain a constant voltage until they are nearly depleted, then they cut off, so the battery level meter on the D6 is of no use for showing battery charge condition.
I'm using the Hixon 3500mWh AA batteries (that I bought last year on eBay). I got the charger too, which works with any 5V 2 amp or greater USB power supply.
