I didn't find any troublesome glue, thankfully. No sign of corrosion inside either which is nice. I had some nasty hard glue on my jvc, took a lot of alcohol and picking to get rid of it so was happy to not have that experience again 
Sansui AU-D7
- Thread starter gpounce32768
- Start date
Try some Brasso metal polish. It's the kind that's pre-soaked into a pad that's rolled up inside the little can. I used to use this all the time to polish out the scratches on my Swatch watches back in the day.
Lee.
So I finally got back onto finishing this amp... vacation got in the way and I wanted to upgrade the rotab tooling to be less annoying. Plus its high time I got something else onto the bench;
black acrylic in the lathe, turning the knob;
and the new rotary table tooling on the bridgeport; chuck mounting plate is an old barbell weight- It turned well, very nice cast iron. More of the cast-in lettering remains on the underside, looks pretty funny. The underside of the rim and hub are faced to the same plane so the chuck and hub stack properly on the mill table. The 3-jaw chuck makes op setup a lot faster.
new knob back side. The win is drilling & reaming the knob for a soft PVC insert- in this case 5/8" diam and 800" long. I drilled it with a #1, then heated a splined potentiometer shaft and pressed it in & repeated a few times to mold something like a female spline. A #2 or #3 drill would make for a deeper spline. Counterbored the other end for a potentiometer shaft clearance so just the last .200" or so has the spline- this avoids needing to use excessive force on the amp when installing the knob. The insert is set with a light press-fit and 8-32 dutchman screw to lock it- 6-32 would be better but this works fine.
Here is the final pic, indicator groove was formed by milling with a countersink tool as engraver. It is not painted, illumination is exaggerating its brightness. The alcohol bath residue can be seen behind the meter bezel- I would have to break it out to clean that area, didn't want to go that far. I am inclined to make this amp my basement monster, it has so much punch and the JVC quad doesn't have the low volume finesse this one does- and I like the eq curve on the Sansui better.
black acrylic in the lathe, turning the knob;
and the new rotary table tooling on the bridgeport; chuck mounting plate is an old barbell weight- It turned well, very nice cast iron. More of the cast-in lettering remains on the underside, looks pretty funny. The underside of the rim and hub are faced to the same plane so the chuck and hub stack properly on the mill table. The 3-jaw chuck makes op setup a lot faster.
new knob back side. The win is drilling & reaming the knob for a soft PVC insert- in this case 5/8" diam and 800" long. I drilled it with a #1, then heated a splined potentiometer shaft and pressed it in & repeated a few times to mold something like a female spline. A #2 or #3 drill would make for a deeper spline. Counterbored the other end for a potentiometer shaft clearance so just the last .200" or so has the spline- this avoids needing to use excessive force on the amp when installing the knob. The insert is set with a light press-fit and 8-32 dutchman screw to lock it- 6-32 would be better but this works fine.
Here is the final pic, indicator groove was formed by milling with a countersink tool as engraver. It is not painted, illumination is exaggerating its brightness. The alcohol bath residue can be seen behind the meter bezel- I would have to break it out to clean that area, didn't want to go that far. I am inclined to make this amp my basement monster, it has so much punch and the JVC quad doesn't have the low volume finesse this one does- and I like the eq curve on the Sansui better.
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Fredrik 1977
Super Member
great work! aint it great getting these wrecks up and running?
they are always the ones i look for. the more wrecked the better
and great work on that knob! now i know who to call for knobs
they are always the ones i look for. the more wrecked the better
and great work on that knob! now i know who to call for knobs
Fredrik 1977
Super Member
we are the last line of defense for these types of units
i missed out on this fix-up, but i wont miss the next for shure.
i believe i had the little brother of that one some many years ago.. looked very similar but i cant remember wich model.
i missed out on this fix-up, but i wont miss the next for shure.
i believe i had the little brother of that one some many years ago.. looked very similar but i cant remember wich model.
HifiChoctaw
New Member
I know this thread is dead...But I was reading along,because I have an AU D7 heading to my shop..I am doing some trading with a guy that I have had some dealings with before...and just getting familiar with the unit...I wanted to inject a bit..something I have used in the past is Nylatron for knobs...Years ago we used in the Locomotive machine shop I worked at..A great product with a ton of durability....Just my .2 worth...more importantly...well done on the amp..