Audio Discussion > DIY

Dual 721 repair

(1/3) > >>

scorpio333:
For the past week and a half I've been repairing and/or fighting my 721. I've only tackled the mechanical side of it, there are some electrical tune ups that need made. This all started because I was trying to adjust the VTA and things got weird. After inspecting it, I found the following part was broken.



Luckily I found what is believed to be the last two available, right here in the Burgh from dual-parts. I bought both, one is going to Quebec to Klaus, a former Dual service manager and good human. His guidance in this has been amazing. Klaus was a driving force to getting new dearings made for 12xx series tables, a broken dearing was fatal to those tables and now there are brand new parts available. The broken and new pieces are going his way to hopefully make new helixes for the 721's. They'll sort of work with the broken part, but it can be insanely finicky.

Along the way I found out there was a missing ball bearing in one of the races in the gimbal, I lost a spring (I HATE SPRINGS) and damaged a tracking force wheel. Everything is coming back to together slowly. I took pics along way of the disassembly (reassemble in reverse order!). Figured I might as well share in case anyone likes torture pictures or gets bored and wants to tear down their table which I don't necessarily recommend.

pix.sfly.com/CEXQt9Yj

Sir Thrift-a-Lot:
You are infinitely more patient than I.   I curse at pens when I'm putting in a refill and the spring gets lost.   One more reason to be a direct drive guy.

scorpio333:
Patience isn't my strong suit. However, this is one of the more regarded Duals. When it was introduced it was the quietest table rumble-wise available.

This table was covered in nicotine so a near complete teardown to clean it was in order.

The 721 is a direct drive, but also a full automatic table. There a nearly a dozen springs on it. I shouldn't have mentioned springs because the tracking wheel i tried from a 1237 won't work so now I need to pull out the tweezers to try and repair the original. The 1237 is on the left and has a nice tight 90 degree bend on the end of the spring. The 721 wheel on the right is out of square enough that it slips out of a notch on the dearing. There's plenty of cursing going on here.

Sir Thrift-a-Lot:
If it were mine it would be in the bottom of the Mon by now.

EmperorNorton:
Scorpio,

The 721 I bought recently apparently needs some attention.  The on/off switch has a lot of play in it, for one thing.  Not sure if the "fully automatic" function works consistently, as I've been manually placing the needle down to begin playing records.

Mike

Navigation

[0] Message Index

[#] Next page