I ended up moving the turntable back to the spiked audio rack and the problem was solved. I have no more feedback. I guess this type of deck likes spikes for isolation. I should get my Denon cart back tomorrow!
Well I had a little time on the Bridgeport today, added corner radius and milled out the main cavity on both armboards. They dropped in the plinth with no room to spare. Next up is to mill pockets for the replaceable armboard inserts. After that I will make an insert for the rear position for my ATP-12T arm.
That worked out perfectly! I am still looking forward to the finished product.
I received my Denon DL103 LC II back from VAS. I spent nearly an hour getting it set up...VTA, azimuth, overhang, both null points and VTF. The hyperelliptic stylus takes the cart to a new level for sure. It sounds great! I ended up using the stock headshell because the Koetsu was just too heavy to balance the arm properly. I have been spending every evening listening to various albums and am very pleased. One thing I wish I could correct in myself is that I have a habit of only listening to good pressings. I hate to listen to poorly mastered or worn out records. I am the same way with my digital stuff. Am I the only one that does this??!! You were right about the Denon as a good match for the arm!
Ok, had a little time today, finished the main sub armboards and glass beaded them for a nice satin finish.
Now I need to get some more aluminum plate for the armboard inserts, a piece to make the bracket for the tonearm cuing device and a piece of bar to make a tool to mark the tonearm position. That will register on the platter spindle and have a scribe to mark the tonearm mounting distance.
Made up a few inserts for the armboards out of 1/4" aluminum plate and made a gauge to mark out the spindle centerline to pivot centerline. Also found a deal on a recapped and totally serviced TT 71 quartz locked motor unit. Installed that as well.