I'm working on my first Sansui AU-111 rebuild. This is an older unit, ~1964, and I'm putting together orders to re-cap the thing.
This is a friend's Uncle's unit, and it sat in a garage for more than a decade, so it had a good bit of dust, cobwebs, and the occasional roach leg inside. That's all cleaned out now.
One issue I'd like to solicit opinions on: The Uncle was a heavy smoker, so I've been cleaning the inside with isopropyl alcohol, brushes, and paper towels, but the metal finish on all of the interior chassis parts is pitted and kind of sad looking. I'm perfectly content to leave it as it is (cleaned, though) and just rebuild the electronics, but I'm wondering if anyone has any tricks or methods to clean and shine up the interior chassis, or would you just leave it as is? I see some pictures of others that are nice and shiny metal, and this one inside is a dull pitted gray. Thoughts?
This is a friend's Uncle's unit, and it sat in a garage for more than a decade, so it had a good bit of dust, cobwebs, and the occasional roach leg inside. That's all cleaned out now.
One issue I'd like to solicit opinions on: The Uncle was a heavy smoker, so I've been cleaning the inside with isopropyl alcohol, brushes, and paper towels, but the metal finish on all of the interior chassis parts is pitted and kind of sad looking. I'm perfectly content to leave it as it is (cleaned, though) and just rebuild the electronics, but I'm wondering if anyone has any tricks or methods to clean and shine up the interior chassis, or would you just leave it as is? I see some pictures of others that are nice and shiny metal, and this one inside is a dull pitted gray. Thoughts?
I think they most likely used a steel chassis like the 1000A rec. which is cadmium/zinc plated so you have to be careful in polishing it because of the toxic nature of the dust. You don't really want to wear too much of the plating off either as it will then rust easily. I doubt if it's aluminum, just check with a magnet , but the wt. will likely let you know.
I'm working on a capacitor-replacing guide for the AU-111. Here's a link to my cap identification so far:
https://www.dropbox.com/s/ou2x8dwcdvtpi3n/AU-111CAPS.pdf
Page 1 is an overlay to the photo of the chassis underside Page 2, so individual capacitors can be identified. I'm also finishing a numbered guide listing each cap by number and its values so a Bill of Materials can be put together for re-capping an AU-111.
I'll update it this PDF as I go along. I'll do additional pages for the photo preamp board, the front panel board, and the topside of the chassis with the large cans, I just haven't finished those yet.
I've found that the wiring of the channels on the schematic to the tube halves don't match, for example C60 connects to the preamp out/in loop of the right channel on the back of the chassis, but then returns to pin#2, rather than pin#7 of the 6AQ8 tube. It doesn't really matter which channel goes to which half of the tube, but it's helpful to know ahead of time that it doesn't match the schematic pinout, especially if you're troubleshooting. For that reason the cap ID's are correct to the best of my knowledge right now, but it is possible that I might have some cap ID's swapped right-channel for left-channel, as I didn't trace all the signals. For just re-capping it isn't critical to know if you're working for example, with C59 -vs- C60, but for troubleshooting it could make all the difference in the world, so I'm throwing this disclaimer out there. I'll make any corrections needed as I discover any.
https://www.dropbox.com/s/ou2x8dwcdvtpi3n/AU-111CAPS.pdf
Page 1 is an overlay to the photo of the chassis underside Page 2, so individual capacitors can be identified. I'm also finishing a numbered guide listing each cap by number and its values so a Bill of Materials can be put together for re-capping an AU-111.
I'll update it this PDF as I go along. I'll do additional pages for the photo preamp board, the front panel board, and the topside of the chassis with the large cans, I just haven't finished those yet.
I've found that the wiring of the channels on the schematic to the tube halves don't match, for example C60 connects to the preamp out/in loop of the right channel on the back of the chassis, but then returns to pin#2, rather than pin#7 of the 6AQ8 tube. It doesn't really matter which channel goes to which half of the tube, but it's helpful to know ahead of time that it doesn't match the schematic pinout, especially if you're troubleshooting. For that reason the cap ID's are correct to the best of my knowledge right now, but it is possible that I might have some cap ID's swapped right-channel for left-channel, as I didn't trace all the signals. For just re-capping it isn't critical to know if you're working for example, with C59 -vs- C60, but for troubleshooting it could make all the difference in the world, so I'm throwing this disclaimer out there. I'll make any corrections needed as I discover any.
Updated the PDF, page order is different now, there are overlays for the chassis underside, front panel backside, and front and back of the phono board. There's a complete Capacitor value list, and a copy of the schematic with a blowup of the phono section, and tube layout.
Had to move files off my Dropbox at some point. Here's the cap guide re-hosted:
Sansui AU-111 Cap Replacement Guide
Sansui AU-111 Cap Replacement Guide