I promised to post a picture a while ago - and here it is. I t is a story about a turntable that strayed far away from its home.
that is absolutely all that is written on it - NOTHING more, even if and when you disassemble the thing.
The thing arrived one day through an acquaintance of a friend - couple of years ago. It had a headshell and a cartridge. There was no belt on this TT.
I thought it was an Acoustic Research 11 - nope. Audio Research, known manufacturer of (tube) audio electronics also did not produce it. The belt required is LARGE - in fact, it is the largest belt possible without actually running on the outside of the platter rim.
I searched far and wide, and finally determined its manufacturer, or better said, its seller : Audio Reflex from Canada. Through many forums, I finally found a picture of something reasonably similar, obviously a later model : http://www.canuckaudiomart.com/details/115762-ags_audio_reflex_mr_112_turntable/ Even that info of model number etc did not yield any useable info on the belt required - all that was listed as a belt for Audio Reflex turntables was simply too small. Finally, it dawned to me to search for " 285 mm diameter belt" - yes it really is that large diameter on the platter ! - which led me to http://www.donberg.co.uk/warehs/groupab.htm (actually to their outlet in Ireland ) and there I finally got my belt http://www.donberg.co.uk/catalogue/audio_spares/audio_belts/araf_331.html . They were very friendly and supplied very fast - if you need a belt and do not want to pay markup artists that sell most probably similar if not the same belts at much higher prices strictly by make/model without specifying lenght/diameter , you should perhaps bookmark that link.
I knew it is not over yet, when I received the package with belt(s). My worst fear was confirmed upon mounting the belt and switcing the AR-11 on . It did run too slow. In North America, mains frequency is 60 Hz and in Europe it is 50 Hz - with synchronous motor as fitted to the AR-11, this means pulley change. Which in so old model so far away from its home market means getting someone to make a custom pulley - or scrap the TT. Now I know it is possible to use any PSUs for AC sinchronous motor driven belt drive turntables - built for North America's 60 Hz mains AND 240 V AC - next to mossion impossible in any commercially available product. Or I could design one from scratch.
I opted for the most guerilla McGyver approach instead - I simply recalculated the ratios and let approx calculated lenght of PTFE teflon tape ( used for sealing etc ) to wind itself upon the existing pulley. In photo above, you can see the brass original pulley partly covered with multiple turns of the thinnest teflon tape I could find - wound on the pulley diameter for 33 1/3 RPM. Below is the same photo, but belt on the 45 RPM diameter of the pulley :
Believe it or not, I was able to make the thing run with less than a 0.1 % error in speed at 33 1/3 RPM, and know I can do better than that with this teflon McGyver mod - eventually making it OK both for 33 1/3 and 45 RPM. Granted, not as good as properly machined pulley, but it can be made surprisingly smooth and compared to the vibration inherent in synchronous motor, should not result in appreciably worse performance - once you allow for all the stuff mentioned in my previous post just above.
The greatest downfall of this table is its arm - no antiskating, no VTA, the whole arm pipe swiwel around 10 degrees in the joint with part that carries bearings, etc - but it nevertheless does sound quite decent indeed ! I tried several carts/headshells, and the sheer solidity of the sound, no doubt due to very decent main bearing, made me to start toying with an idea to either mount another decent arm ( difficult without visible change to the plinth ) or just use the platter, main bearing and motor and build a TT from scratch around these parts. Here a shot "below the hood" showing its workings :
Here the pic of the platter, showing its 285 mm diameter where belt rides :
Allegedly built by CEC in Japan - hats off, they don't make them that solid anymore !