WM-D6C pointy

So what is the difference between the "pointy" amorphous heads used on early Sony WM-D6C Walkmans and the "regular" amorphous heads? Is there a performance difference or is it simply cosmetic? And when exactly did this change happen? Some postings seem to lean toward about serial # 80000 being the change point

 

I believe we started a similar discussion, or exchange of thoughts rather, in the thread about the DD Genealogy.

 

Pointy cost more.
Regular costs regular.

 

The highest serial # with a "pointy" head I have found is # 71236 :. The next serial # I have found is #72265 and that has the rounded 35711 head. So the changeover is SOONER than the previously reported #80,000.

 

Is there evidence in Sony documentation? I will update the table regardless with a clarifying note.

 

Hi..
I have 2 dc6 but they have a high serial number one 220...and the other 221...
on top of both there is the head 35711 However I did a bit of research and looking at the manual in my possession
I found only two types of heads called HRP 901 but with a different part number 8-825-529-60 (PA259-3602A) which corresponds to the pointed head the other one I found is 1-543-357-11 but this is mounted on the latest versions...
but if you do a search online you can still find other info

Example.. you can see here
WM-D6C serial numbers and more | Stereo2Go forums

and also here
Sony WM- D6C – amorphous head history | Tapeheads.net

 

There should be 3 types according to my research a while ago for the DD genealogy and timeline, and 4 generations of D6C releases.
1) 3602A,
2) 35711,
3) 35712.
Reply to my post with cutover serial ranges or other properties that differ per generation, so I can update the table and when needed introduce the generations in the timeline.

 

dotneck335: "The highest serial # with a "pointy" head I have found is #53613. The next serial # I have found is #72265 and that has the rounded 35711 head."
Emiel: "Is there evidence in Sony documentation?"
NO, not that I was able to find. I am basing my statement on pictures I have seen posted on eBay with For Sale postings. This is what I have:
FIRST versions of the WM-D6C came out in 1984. These had "pointy" amorphous heads marked 'Japan"; PC bords suffix -11
SECOND version was suffix -12 PCBs that had the Dolby chip change from CX20068 to CX20218. Documented in Supplement 1 (Jan 1985). Serial # units unknown.
The next change was from the 'pointy" amorphous head to the rounded one marked '35711'. This occurred between serial #71236 and # 72265. Dates unknown.
The next change that I am aware of was the color of the Dolby sticker on the back, from silver/white with black lettering to black with white lettering. This occurred in 1988 between serial # 114371 and serial # 117947
There is some indication the PC board changed from brown to green around serial # 180000 but info is very vague.
Supplement 2 (March 1994, serial # 267,201) showed the change to surface-mount components. Head part # shown is 1-543-357-11
Head changed to permalloy type marked 35712. Dates unknown. Probable serial #50xxxx and above
Supplement 3 (April 1999) only showed 2 resistor value changes for the French model
Supplement 4(May 2001) showed the servo circuit update, with IC601 = CX-069A

 

I confirm what is written I looked at the entire manual with the revisions that
I have I found the changes made to the circuit with the various components as explained by @dotneck335
This is the last page of the manual with the dates of the revisions starting from the bottom 1984 when it came out...going up
The 35712 head in the manual that I have is not seen anywhere and probably Sony has never specified this modification

 

"The 35712 head in the manual that I have...."
What manual is that? None of the manuals or supplements I have seen show that head number.

 

@dotneck335 Can you upload supplements 3 and 4 here ?

 

I got a weird one, my D6C has the regular non-pointy 35711 head and the old through-hole PCB, but the serial number is 651xxx.....

 

"Can you upload supplements 3 and 4 here ?"
They were part of the service manual I downloaded from hifi engine. I tried to upload it here but it says it is too large. I don't know how to separate the supplements from the rest of the manual which is in .pdf format. Do you have access to hifi engine? If not I could maybe send the file to you by PM.

 

"I got a weird one, my D6C has the regular non-pointy 35711 head and the old through-hole PCB, but the serial number is 651xxx..... "
Are you absolutely SURE that number has SIX digits? It sure sounds like a five-digit unit.

 

Yeah 100%... the only explanation I have is that someone changed the sticker or something but doesn't make sense or look like it was ever removed. Didn't look like it had been opened up before I got it either.

 

In all my research, I have NEVER seen a serial number that high----highest has been in the 50xxxx range. Got a picture of it?

 

Sure, here it is:

 

You probably can't separate since most of these PDFs are locked and cannot be edited. As a suggestion, don't upload anything from HiFiengine on the forum.
Thanks for the info, will download that manual since the ones I have don't containt these supplements.

 

here are the supplements divided as requested

 

I wonder if it’s had a head job at one stage?
Can anyone shed some light on my serial number
It starts with an E? What does the E stand for?

Cheers Kiwinut