This is an aftermarket thing (remember kids, Linn ownership is all about upgrades, right?), made to put two speeds on your Linn LP12, without all that tedious belt pulley swapping business...
Look familiar?
It's almost identical to a Valhalla, except it has some logic to switch between speeds like an Axis, and has two oscillators, and an analogue switch stuck before the pulse shaping, to change between the two oscillators.... oh and the print doesn't fall off when you touch it with an iron...
Anyway , this is my good friend Colin's, he's done the caps (and done a tidy job too), and it's still no good...
A quick check of the two crystal oscillators show they're both working, and so are the dividers. The output frequencies are 50Hz for 33RPM, and 67.5Hz for 45RPM. Both are present at the 4066 switch, and make it on through the pulse shaper , and are all fine at the output on pin 14 of U2 (again, sound familiar???) Everything goes pear shaped on the output driver at pin 8 though ....
Changing out U2 (an LM324 , instead of the LM2902 in a Linn supply) provides a cure.
Another Linny happy.... until the next upgrade....
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