GyroDec blog

My gyro has been sounding a bit off for a week or two. Somewhat flat & listless compared to how it usually sounds. Everything seemed to be present & correct but just not an involving listen. As nothing had obviously changed I ignored it for a while, after all there are many other things that can affect how much we enjoy music, so maybe it wasn't the deck at all?
 
Anyway last night I couldn't stand it any more so I stripped it down and set it up again from the ground up. Levelled the spider subchassis, made a bit more of an effort to balance the main chassis, by adding some more denso-damp to the area behind the front weight & at the motor "ear". New bearing oil, new belt (I had spares) and re-levelled the deck.
 
This time I levelled it by borrowing a properly calibrated level (very important) that they use in the machine shop at work. This is far more accurate than any bubble level I've tried (I own 2). Fortunately, or rather by design I should say, a tripod is the easiest thing to level. I levelled it first across the front towers & then front to back as close to the centre as I could get it. I did this at every stage of the rebuild (spider/chassis/platter)

While I was at it I swapped the cartridge leads replacing the ones that came with the arm with the ones that came with the cart. Just a whim really and it turned out to be pain in the butt actually as the new leads were not as flexible as the old ones and my near vision ain't too great. I've set the arm & cart up again, though I'm gonna let it all settle down for a couple of days & then tweak it some more.

Pleasingly, the sound seems to have recovered much of it's clarity & sparkle, drawing me into the soundstage again. I detect a slight mid bass bloom that I need to tune out but it's close to how it sounded at it's best. A bit more fettling should do it.

Been at least 6 months since I've done any set up at all on the deck and the SME in particular tends to stay put once you have it set correctly, so I guess like a car it just needed a service & tune up.

Quite a bit of work so far and I'm not quite done yet, but somehow the effort spent makes me appreciate what I have all the more.




Edited by DaveG - 09 Jan 2016 at 1:34pm

Well I haven't actually listened to anything but vinyl in ages. In all probability the solution was simpler, these things don't just suddenly go massively out of kilter - maybe just check alignment, tracking force, vta etc. However, once I start I kinda get wrapped up in it. Part of the fun for me is getting to know this stuff inside out and how I can tease the best out of it. I can do that with mechanical devices whereas electronics are totally beyond me. I'd also been intending to try a couple of things Jon wrote about in his blog, particularly the chassis balancing part, as our decks are similar. I do use deoxit occasionally, though not this time.

On further listening and some considerable time messing with vta and alignment I decided that although the rebuild improved things somewhat, it still wasn't quite there, this thing can sound amazing but I refused to be amazed. The slightly wayward bass wouldn't go away and moreover I was now having trouble with the clamp. So off came the platter and bearing again and suddenly the problem was obvious! The male part of the bearing - the spindle bit - screws up from underneath the chassis (surely the top would be a better idea??) and it had worked loose, sitting about 1 - 1.5mm low and a bit wobbly. I've re-tightened it which was a bit awkward without separating the spider & the chassis again, but it's now singing like a lark. I'm tempted to put some threadlock on it to stop it happening in the future, but that definitely requires me to strip it down again. Maybe next weekend if I'm in the mood.