5 Attachment(s)
Rega RB-300 tonearm on Technics SL-1200Mk2
Inspired by Qwinn. Origin see here: https://www.jkwynn.co.uk//Tech2_HTML/Tech2_14.html
Part 1 - Tonearm base and fitting
I posted early my DIY silicon fluid damper for SL-1200Mk2 tonearms https://theartofsound.net/forum/show...704#post848704 . Despite it works perfect, I decided to replace the whole tonearm, RB-300 or -250 was the best performance/price choise for me. Bought RB-300 on e-bay in good condition (-250 could be cheaper choise but I didn't find suitable offer).
Loading spring was tuned to zero force and damped by small soft textil pieces (I leave backdoor).
The first issue is the tonearm base. All necessary calculations already made by Qwinn, see link abowe. I've make several top view photos/measurements and by simple geometry calculations got absolutely the same (no wonder).
Ok, all drawings are ready, tonearm base will be made from oak. Simple rotary attachment to mini-mill, some lathe finish, varnishing and base is done.
Attachment 31018 Attachment 31014
The next issue is tonearm height adjustment. Classical Techie has perfectly designed (really perfectly) hight adjustment mechanics but it can't fit RB-300 tonearms. I turned out aluminium hub (upper part) and nut (both have metric thread with 1 mm pitch) according to tonearm 'leg' thread. Don't ask me why british tonearm has metric thread, I expected something like 15/16-20. BTW, there is one of prototype of tonearm base I've made by 3D printer on photo (3D print is very useful for prototyping).
Attachment 31015
The next point is internal and external wiring. Of course, default ones should be replaced. Internal wirings replaced with litz, external - with Klotz shielded twisted pair, it requires new wires holder on the tonearm 'leg'. Lathe again, drill press... done. Sure, I fitted balanced XLR connectors instead of RCA.
Attachment 31016 Attachment 31017
Again - many thanks to Quinn. Next is new couterweight.