A close look at  the JJ series  from Sanyo.   from the full body JJ and the JJ ll to the small quarter JJ.  These early Sanyo walkmans are a great find!

One can not be too impressed when it comes to the engineering marvel the 1/4 JJ managed as it is officially the smallest Walkman ever made JJ-P4 and the beauty of its simple design.   Just beyond painfully hard to work on or repair due to extreme small size of everything inside and the lack of durability that too tiny parts tended to cause.  Also the slightly larger JJF4.

SANYO JJP4

Dean you should always put the model number of the Walkman with a photo so members with less knowledge will know which player is what model.

I have done this before but none of it showed up!  Did I miss a step? Do I have to click the "insert in body" for caption to show up?  

Dean before each photo just put some model name...

Dean I type in body of post like this 

SONY WM-40 with CTP-1A     

then here I attach the photo.

Can someone help me with the belt size required for the Sanyo JJ-F4? It is so tiny and with wires that need to be unsoldered to really get at it, I don't know if I can figure out the belt size. Plus a source if you can Thanks!

I have a belt sizer for the USA !  So if you live here I have the belts also,if not, try Doc P?

Andrew, if you're still looking for a belt for your Sanyo JJ-P4:

I recently bought a Sanyo JJ-P4, cheaply as is was sold as untested and with a bent lid (latter easily rectified with a bit of creative force)...and also the identically designed Grundig BB-900 in a similarly neglected state.  My intention is to use both in order to at least get one working.  Thankfully one had a belt which was very much intact:  I measured it as being 16cm or 6-and-a-quarter inches in circumference.  It is also pretty thin, probably a 0.8mm one that I've seen people talking about...certainly less than a whole 1mm thick (I doubt that would sit well in the spools.  Haven't ordered any yet but will be... If you have been successful since your last post then I would appreciate you wisdom.

So, like you I had never taken any electro-mechanical device apart before. Really quite fun though.  Just be careful about your screwdriving abilities...it is very easy to accidently burl the screws.  Also, opening up the guts will probably (as happened to me) detach some minute wiressoldering which completes a circuit for the internal gumstick battery.  So I will have to buy the manual in order to learn where these loose wires solder too - annoyingly this isn't obvious.  Still, I'm getting there.

If anyone is interested...my intention is to get the Sanyo fully up and running (only task left is to get it functioning on it's internal battery to really enjoy it's small size.  Then...THEN...and this is the ambitious bit, and might upset some purists out there, I might try to modify the slightly less attractive and less iconic Grundig even smaller.  Yep, that's right, I'm going to try out for the smallest ever.  In no rush...but this might take the form of fitting a new thinner battery system as would be found in the iPod (the Devil's music system of choice).  Also, perhaps by soldering the DOLBY to permanent on...same with METALNORM...and a more modern headphone jack???  Who knows...perhaps the circuit board could now be shrunken down with modern processes.  All these mods...aggregated out...and one might be able to shave-off yet more volume.

This might be too wistful...but I would seriously enjoy the challenge.  Who knows, this might even have the makings of a Kick starter project.  Perhaps the body could be 3D scanned and re-milled in scratch-proof tungsten.  How awesome would that be?

Anyone out there with suggestions about the latter project???

Thanks James, especially for the belt length info. I had taken it apart back then but put it back together (unrepaired) so I would not lose any parts. I hope I can remember where to solder those wires on too! 

Actually I have no problem taking electro-mechanical things apart. I actually do it all the time but my specialty is fixing turntables, among other things. This is just on a smaller scale. I do have a rather large boombox to fix too though...

Your nudge might get me back to work on the Sanyo. I even bought some belts a while ago too so will have to check to see if one that size is in there. Yes, it sure is narrow. 

Good luck on the Grundig project.