I'm still looking to buy a DD walkman. I noticed that very very first ones weren't quartz controlled. Some later models also lack the word quartz. I assume that if the word quartz isn't on the body then the walkman isn't quartz. Is this correct ? For those of you who have different working models : do you hear the difference in speed stability between a quartz and a non quartz DD ?
Hi RevDoc.The answer is yes to both questions. Quartz is more impressive because you don't hear any speed instability rather than how stable is the speed... if that makes sense.
I'm afraid I have to disagree with sotza on the first question.... The DD9, DC2, D3 and D6C models don't have the 'quartz' label on the case but they are all in fact using a quartz controlled servo system to control the speed of the DD motor (or the 2 motors in case of the DD9). On the second question: in theory the quartz control does improve the stability of the motor speed although the improvement that the Direct Drive motor brings compared to other manufacturers mechanics is probably more noticeable. Even the DD-I and DD-II sound much better in terms of speed variations, and ability to deal with shocks, than most (if not all) of the competition. That said, I can't hear a clear difference in speed stability between my DD-II and my DD-33. But both of them are in need of some maintenance & DD-clack remedy. So I'm not sure if I'm the best point of reference here. Maybe one of the more experienced board members with perfectly serviced quartz and non-quartz WM-DD can chime in here?
RevDoc either you meant DD labeled or disc drive in general here is your guide, only d3 is labeled with the words servo capstan without the word quartz.
Firstly they are Disc Drive not Direct Drive, direct drive is something completely different altogether. You only really start to notice the DD vs non DD models, when you start to shake them about while they are playing. The DD models will be more stable and the non DD models will be all over the place.
Oh boy, just recently signed up to this site and now already made so many mistakes... I consider my statements on 'not having the quartz label on the case' to be sufficiently corrected by sotza's nice pictures, thanks for that. And thanks to TooCooL4 for correcting the fundamental DD mistake as well: in this case it is Disc Drive indeed! (as opposed to the Direct Drive Dual Capstan thing that is such a big topic on stationary decks) I still have a lot to learn and am pleased to see that this forum offers plenty of opportunity for that
Oh come on Middachten we all do mistakes . And welcome aboard !. The point of pictures was to help everyone reading this to know what is correct ,although you have a point there. There is one "DD" model with the words "servo capstan" but no "quartz", didn't mention it because I didn't think RevDoc would consider it in his comparison with the other DD's.The DD-100 or more widely known as"BoodoKhan". As for the disk drive is a simple (reliable) system so the force of the capstan is multiplied by a high rev motor.The very low voltages and currents of a walkman were probably the factors that made the technicians to avoid a direct drive motor-capstan so this is a wise decision.
What i noticed from this topic; question >> Answer >> challenge >> explanation >> respect >> education conclusion : valuable members
I did actually note this one when I quickly researched the DD/disk drive information. But didn't want to sound too smart when responding to your 'picturesque' message Weird thing BTW: they don't advertise one of the key technologies on one of their most expensive walkmans. Instead they make a big thing out of Mega Bass, something I could personally easily live without! You are right about the power hungry nature of a real direct drive solution, let alone the diameter that is fundamentally need to generate enough torque. Interestingly enough I always associated the DD term with direct drive because there are no belts involved for the capstan drive. One question that intrigues me now: where does the name Disc Drive come from? Is the drive similar to the way floppy disk drives operated at that time? A
Thanks for your replies ! I just payed for my first DD walkman and it will be on it's way starting tomorrow. I've chosen to buy a black WM-DD III because I like the design of the earlier models the most. It's been advertised as fully functional but after a lot of research I'm going to assume that the center wheel is broken but not too much. What is for sure is that the unit has not been used much.. It looks almost mint, no visible scratches. Now I'm in doubt wether to wait for Marian's new center wheel or an attempt at a repairing the old one. What I meant with my orignal question : Some DD walkmans are explicitly Quartz while others aren't. Maybe it woul be good to compile a definitive list because up to now I haven't found one anywhere on the net. The Walkman So here's my attempt with info compiled from the excellent Walkman Archive & Walkman Central and Hifiengine. As you can see I added the years of production if I could find them : Quartz models : WM-D6 (1982-1984) WM-D6C (1984-94) WM-DD3 WM-DC2 (1984-89) WM-DD30 WM-DD22 (1993-94) WM-DD33 (1991-94) WM-DD9 (1989-92) Non-Quartz models : WM-DD (1982-1986) WM-DD1 (is this the same as WM-DD ?) WM-F5 (1983 - ? ) (The very first Sports Walkman but it uses the DD mechanism !) WM-DD2 (1984 - ?) WM-D3 (1986-92) WM-DD100 (Boodoo Khan) (1986- ?) WM-DD10 (1989? -1990) WM-DD11 (1990-1992) If I've made any errors please point them out so I can edit and there will be a definitive list including all the DD models. The main question is if "Capstan Servo" equals "quartz controlled" Thanks in advance
In question are DD-100 and D3 For DD-100 "BoodoKhan" can' t be certain don't have service manual for D3 a quick search shows no crystal in the relevant circuit, only a servo IC and no crystal in the parts list. On the other hand ,for example, in D6C service manual there is a crystal and a servo IC in the circuit schematics and in the parts list.Unless someone knows otherwise your list is correct.
I believe this is correct: the D3 for certain doesn't have a quartz controlled servo. The schematics in the service doc are quite clear on that. Since the BoodoKhan is based on the DD2, and there is no Quartz advertisement what so ever on the casing I think we can safely assume it to be a non-Quartz model. Although I also don't have a service doc to check it. A question though: is the DD11 from 1990-1992? I don't have a service doc for that model and there is no 'Quartz' on the casing, but I would assume that a WM of that vintage would have the Quartz servo? But I don't know the heritage of this model, and the (otherwise excellent) overview on the walkmancentral.com site doesn't include this model.
It seems the DD11 is a Quartz model : I just found a German 1991-1992 catalogue through higfiengine. In the catalogue it is stated the the DD-11 is Quartz controlled. So the DD11 would be the exeption where it's not stated on the device itself, at least not on the front. I'll move it up to the quartz controlled list in my original post The 1990-1992 reference also come from the hifiengine website and is probably correct.
RevDoc, that is interesting. I wasn't able to find the DD11 on hifiengine initially. But now I did. And there is a service doc with full schematics. This doesn's show any crystal controlled servo. See attached. Based on this rather clear evidence, I would say the DD11 is not Quartz! I now also have seen the entire schematic and must conclude that this is probably DD walkman in it's simplest form: only 4 (3 for audio, 1 for motor servo) integrated circuits with a minimum amount of discrete components, that's all. Never heard one, but based on the ICs in the signal path I can't imagine the DD11 to be a brilliant performer audio wise...
I got the quartz reference for the DD-11 from a german brochure that is on hifiengine You must be logged in to hifiengine to be able to view the catalogue (WM-DD11 is on page 33): https://www.hifiengine.com/hfe_downloads/index.php?sony/sony_product_cat_1991_part3.pdf It must have an error so I'll move the DD11 back to the non quartz section.
I found a DD-100 "Boodokhan" service manual and there is no Quartz crystal, in comparison with D6C they share the same servo IC, the CX20084 but the DD-100 lacks the quartz and the relevant IC the MSM 58141RS. The parts lists are in alphabetical order and as the crystals have an X designation (eg.R for resistors) they are at the end of the list,as you can see below dd100 has no crystal. When we read "Quartz" ,"Capstan Servo" on a D6C Sony means this... ...and when we read "Capstan Servo" on a DD-100 Sony means this :
The speed stability (W&F) with or without the quartz is basically the same as the limiting factor is the mechanical accuracy of the flywheel and the tape transport overall. In the DD walkman's the rotation speed of the capstan is locked though a PLL (Phase Locked Loop) to a local oscillator: that means the capstan provide an electric feedback on its rotation speed and that feedback is compared to a local oscillator; any difference between the two signals generates a corrective action on the motor. In the non-quartzed DD (wm-dd and wm-dd2) the tape speed can indeed be adjusted as the local oscillator needs to be calibrated. In the quartzed model (DDIII onward) the local oscillator is driven by the narrow frequency filter of the quartz and does not require any adjustment (actually there is an indication of an adjustment, but it requires to defeat the quartz and it is just to make sure the oscillator on its own is close to the frequency of the quartz). Early walkman as TSP-L2 and WM-3 have a similar PLL motor control, but the feedback is provided by the motor itself rather than the capstan.
Thanks enryfox very informative and actually this shows how they where trying to improve their products with small but effective steps. I just want to add that the electric feedback from the capstan you mention is provided by a simple coil (designated FG at the schematics in my post above) that is attached by two wires on the pcb.If there are speed stability problems after a repair maybe accidentally one (or both) of these wires is detached.
The FG is a simple coil which was designed in an era where there were no real concern for EMI (Electro Magnetic Interference): the coil easily detects interference from mobile phone and that drives the DD crazy. If there is no feedback from the capstan coil, after a couple of seconds the motor is shut down (i.e. if the PLL does not lock, power is cut to the DD circuitry). That is "auto-stop" implementation for FFW and REW and hence the walkman does not operate if one of the two FG wires is detached (the autostop on playback is indeed mechanical). The DD circuitry is actually a dead end, after DD33 they moved to different approaches; I have not investigated much but I suspect that later walkman's with feather touch command and disc motor were actually driven by square wave signal (like step motors). Anyway the idea to get a feedback from the capstan was abandoned in favour of a tight control on the rotation of the motor itself.
That's interesting.That's why in some repair guides if everything seems ok with the servo IC is suggested to check the FG coil . When you say "autostop " implementation you mean when the tape ends in FFW or REW the capstan stops to move and the coil gives no feedback to PLL so the power is cut.Is that correct ?
