Barry, it may be worth Googling on FM3 mods. Depending on the tuner's vintage (there was a fairly major revision to the decoding circuit at around #5000 as I recall), there are some caps that can be usefully changed - three supply ones for larger values and at least five around the decoder and audio output coupling. This makes a subtle but beneficial difference to the sound
. I have to get my FM3 out and remind myself what these caps are - I've just found a couple of spare 3300uF 25V caps you could usefully put in the supply feed under the mains transformer (I had to buy five)
http://www.geocities.com/ResearchTri...uadfm3doc.html
The recommendation of C100 and C104 is a thorny one though. I was urged to retain the original value and just replace these with modern ones, but having done the mod exactly as described, I felt it sounded better (I did as I was told in the end), but the important ones not mentioned are the audio output coupling caps (I'll find the numbers).
Suitably serviced, the FM3 still sounds a touch "dry" but I thought the clarity was better and if it's feeding a high impedance pre as recommended (50K at least), you should get a pretty truthful reproduction (I still find the FM2 too soggy and soft, but I'm told it's the stereo decoder at fault).