skippy124 Posted September 13, 2013 Posted September 13, 2013 Thought it was time for another AU-717 thread!!! Things have been a bit quiet on the bench recently for a number of reasons, but this 717 restoration had been in the pipeline for a long time It arrived a couple of months ago, complete with the original packaging. Mark (lebowski) is the second owner, and this unit is completely original, and has been kept in immaculate condition by both Mark and the original owner. This is without a doubt the cleanest 717 I have seen to date, and it was a pleasure to be able to work on such a pristine example. Out of the box, and top cover removed – just a slight film of dust on the internal panels The front panel is a 10 out of 10 2
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 First work to be done on the amp was to remove the main driver modules, and then remove the caps and clean the glue off the board, and replace the caps. The dreaded corrosive capacitor glue was in better than average condition, and had not dried out. As removed Glue Glue gone The output transistors were removed, cleaned and refitted with new heat sink compound Old dried out heat sink compound Outputs refitted The Bias adjustment pots were also replaced with new multi turn pot for ease and stability of adjustment, and the four fuse resistors on these boards were also replaced. Driver modules finished
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 The next board to be done was the Tone Control board, all electro capacitors were replaced (with Elna Silmic II and Panasonic stacked film for the signal path, and Panasonic FC/FM for decoupling). Four fuse resisters were also replaced, along with two VD1212 diodes. Before After Now, on to the equalizer board As with the tone control board all electro caps were replaced, as well as the fuse resistor and VD1212 diodes. The front panel needs to be removed in order to release the switch shafts for the equlaiser board Equaliser board before And after
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 (edited) The power supply and main filter caps were next to be done. Filter caps removed New Gold Tunes with bypass caps fitted, ready to go back in Power supply board removed Caps removed – although the glue in this amp had not gone dark brown, there was stll some signs of corrosion starting on the 13V zeners The glue was completely removed, including the glue insde the small rectifier diode ceramic standoffs Power supply board rebuilt Edited September 13, 2013 by skippy124
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 Power Supply board refitted, and chassis cleaned Filter cap refitted And resoldered The Power modules were then refitted
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 (edited) The amp was then connected via a dim bulb tester and turned on, with no “unexpected†results. Bias and offset were checked, and then the amp connected directly to the mains and adjustments were completed. A power run gave 107.5W per channel @ 1Khz and 8 ohms before clipping. The amp was run for several house and behaved flawlessly. All internal covers were cleaned and polished (as well a the cover screw heads), and fitted to the amp. The front panel and knobs ha already been cleaned, and these were also refitted, and the rear panel was also given the once over. I didn’t get a shot of the amp with the top cover on, but I reckon they look better with the cover off!! This was a particularly pleasurable restoration, it was great to be able to work on such an original, clean and well looked after 717!! Edited September 13, 2013 by skippy124 6
Luc Posted September 13, 2013 Posted September 13, 2013 Absolutely fantastic John, your dedication and attention to detail is truly awesome and I sit back amazed at your knowledge. I don't actually understand a single thing you say but I love seeing it and hearing it! WD and congrats to Mark too for a fantastic pick up, beautiful bit of black faced magic. Cheers Lee 2
skippy124 Posted September 13, 2013 Author Posted September 13, 2013 Thanks Lee. These vintage Sansui's deserve some dedication and attention to detail, and hopefully once restored will live on for many years to come. I forgot to add a pic of the components that were replaced - Cheers John 1 1
pete_mac Posted September 13, 2013 Posted September 13, 2013 Yep, that's the best 717 in Australia without a doubt - possibly the world. Ultra-minty-goodness. 1
Telecine Posted September 14, 2013 Posted September 14, 2013 Good work on the restoration, that is a minty looking amp.
Monk Posted September 14, 2013 Posted September 14, 2013 Niiiiiiiiiice. I should really look into giving my 719 a once over, but seeing as how it worked when I plugged it in, I've been a bit slack.
pete_mac Posted September 14, 2013 Posted September 14, 2013 Niiiiiiiiiice. I should really look into giving my 719 a once over, but seeing as how it worked when I plugged it in, I've been a bit slack. It's well worth doing. The 719 has similar issues with corrosive glue, and the VD1212 diodes and 'black flag' capacitors are known trouble spots that should be addressss for reliable, trouble-free operation.
Monk Posted September 14, 2013 Posted September 14, 2013 Yeah, I sent a few photos to John and he said it looked like some of the caps had been replaced, but not all. The black flag caps fell into the not replaced category...
The Fez Posted September 15, 2013 Posted September 15, 2013 Yep, that's the best 717 in Australia without a doubt - possibly the world. Ultra-minty-goodness. Bloody beautiful ....Can't wait to get "the big one" on the bench....... 1
lebowski Posted September 15, 2013 Posted September 15, 2013 a huge thanks to John for the work performed on my AU-717. So much care and attention to detail that is rarely found these days, it is much appreciated. It really is in mint condition and Johns work should help it see out another 30 or so years. 1
lebowski Posted September 15, 2013 Posted September 15, 2013 Yep, that's the best 717 in Australia without a doubt - possibly the world. Ultra-minty-goodness. I couldn't wipe the smile off my face when I unpacked it, could easily sit on a display shelf in a hifi store as new. 3
skippy124 Posted September 15, 2013 Author Posted September 15, 2013 I couldn't wipe the smile off my face when I unpacked it, could easily sit on a display shelf in a hifi store as new. I couldn't wipe the smile off my face when taking the final pics (and note the magazine in the first pic in post 6 , says it all ) Cheers John
lebowski Posted September 17, 2013 Posted September 17, 2013 here's the 717 rack mounted in my GX-5 Cabinet. I finished this in American Walnut timber veneer, rack rails were stripped and powder coated in Satin Black. 2
skippy124 Posted September 17, 2013 Author Posted September 17, 2013 Jeebus, nice rack!!! X2 The rack has come up a treat!! Now just the floorstanders left to do
Mushroom01 Posted September 18, 2013 Posted September 18, 2013 Lovely work Skippy! Thanks for the great write up. Congrats Lebowski! A stunning unit. Very lucky man indeed. 1
Dr Good Vibe Posted September 19, 2013 Posted September 19, 2013 Total agreement mush what a beautiful bit of work skips.
lebowski Posted September 19, 2013 Posted September 19, 2013 Total agreement mush what a beautiful bit of work skips.[/size] you can drop by one evening for a listen, I'm just a few doors up from your place now.
danter Posted September 22, 2013 Posted September 22, 2013 (edited) Things have been a bit quiet on the bench recently for a number of reasons ... Crossover Edited September 22, 2013 by danter
Recommended Posts