Dasher Posted December 19, 2012 Posted December 19, 2012 Hi all, Well I received my recapped Sansui AU-717 they other day and it looks fantastic. I changed the power supply to 240 volt and the fuse to 5A, easy. So tonight I finally had some time to set it up and have a listen. I eagerly plug in the speakers, set up the input, hit play........and all I get is a loud hum. So disappointing. I haven't contacted the seller yet as I need to investigate it all further yet and make sure I haven't done anything stupid. Looking at the condition inside I believe he has carried out all the work he claims and looking at his feedback he has a lot of experience doing up these amps. He has also told me he had it running at his house for two months before selling it. I suspect something has gone wrong in transit. Are there any experts out there who may have any suggestions or thoughts? I should mention I have the hum with or without anything plugged in, in both speakers and on A and B speaker terminals.
LogicprObe Posted December 19, 2012 Posted December 19, 2012 No music at all? Just hum? Does it get louder and softer with the Vol control or just stay the same?
skippy124 Posted December 19, 2012 Posted December 19, 2012 (edited) Hi, Sorry to hear that you have problems. Firstly reconfirm that the voltage setting plug is in the correct position. AS LP has said, it is source/volume independent? Some more questions - Does it power up correctly - red power/protection Led flashes for 3-7 secs, and then the protect relay clicks and the LED goes to solid red? Try switching the "connected/separated" switch to "separated" (you will need to loosen the screw that secures the clear plastic switch locking plate), does the hum go away or reduce/increase Cheers John Edited December 19, 2012 by skippy124
Dasher Posted December 19, 2012 Author Posted December 19, 2012 Thanks for getting back to me guys. I am on holidays after today so hopefully I will get some time to check it out further. In the meantime I can tell you that it does power up fine, gets the blinking light which turns solid and you can hear the relay kick in. I haven't had a lot of time on it but at first glance the volume control doesn't seem to affect the volume of the hum. I will try the pre power combo tonight or tomorrow, Thanks again.
Dasher Posted December 20, 2012 Author Posted December 20, 2012 Hi Guys, Well I just had another play with my new toy and found the following. Double checked the power setting and fuse and both are ok. AS LP has said, it is source/volume independent? Nope the volume of the Hum does not change. Does it power up correctly - red power/protection Led flashes for 3-7 secs, and then the protect relay clicks and the LED goes to solid red? Yep all good. Try switching the "connected/separated" switch to "separated" (you will need to loosen the screw that secures the clear plastic switch locking plate), does the hum go away or reduce/increase There is no hum present if I change it seperate, i.e. pre / power. What do you think?
VanArn Posted December 20, 2012 Posted December 20, 2012 Test the hum level with the speakers connected,but nothing at all connected to the inputs.If you still have hum then there is a problem in the amplifier or with the earthing arrangement.If the hum has gone; then you need to double check your selector switch positions,such as tape monitor,Phono,MM or MC and if there is still no audio you would be best served by either returning it to the modifier or to your favourite technician for a test.
Dasher Posted December 20, 2012 Author Posted December 20, 2012 After I found that there was no hum if I ran it separate mode I thought I would try it as a power amp. It works fine as a power amp I am listening to it now. Sent from my HTC One X using Tapatalk 2
skippy124 Posted December 20, 2012 Posted December 20, 2012 Hi Guys, Well I just had another play with my new toy and found the following. Double checked the power setting and fuse and both are ok. AS LP has said, it is source/volume independent? Nope the volume of the Hum does not change. Does it power up correctly - red power/protection Led flashes for 3-7 secs, and then the protect relay clicks and the LED goes to solid red? Yep all good. Try switching the "connected/separated" switch to "separated" (you will need to loosen the screw that secures the clear plastic switch locking plate), does the hum go away or reduce/increase There is no hum present if I change it seperate, i.e. pre / power. What do you think? The hum appears to be coming from the tone control section (due to the hum going when the connected/separated switch is set to separated), and the fact that it is present irrespective of source input selected. Is it the same with Tone defeat switch in either position, also try the subsonic filter switch, the loudness switch and the muting switch one at a time, is there any change in the hum in any position of these switches. Cheers John
Dasher Posted December 20, 2012 Author Posted December 20, 2012 Thanks John I appreciate the help. I will check it out. Sent from my HTC One X using Tapatalk 2
Dasher Posted December 21, 2012 Author Posted December 21, 2012 Hi Guys, Well I have checked it out as you suggested, with nothing connected except the speakers. I have tried all the switches one at a time and they made no difference. The only change is when I use it as a power amp which is fine. John do you have any gut feelings on this and can anyone recommend someone in Melbourne who could look at it for me? Thanks Darren
skippy124 Posted December 21, 2012 Posted December 21, 2012 Hi Darren, Without taking the covers off and doing some further checks, a educated guess would be a problem associated with the tone control board. As it is in both channels it is most likely to be power supply related, and could be as simple as a loose ground connection. I don't know anyone in Vic that I could recommend, possibly a local will have some suggestions Cheers John
lebowski Posted December 21, 2012 Posted December 21, 2012 Hi Darren, I recall cheekyboy mentioning a vintage Amp tech here in Melbourne that has a good reputation. Perhaps send him a PM.
LogicprObe Posted December 21, 2012 Posted December 21, 2012 Hi Darren, Without taking the covers off and doing some further checks, a educated guess would be a problem associated with the tone control board. As it is in both channels it is most likely to be power supply related, and could be as simple as a loose ground connection. I don't know anyone in Vic that I could recommend, possibly a local will have some suggestions Cheers John I agree. If it has been reconditioned..........it may be just a dry joint.
Dasher Posted December 22, 2012 Author Posted December 22, 2012 Hi Guys, Thanks for the help I will try to get in touch with cheekyboy.
Dasher Posted January 19, 2013 Author Posted January 19, 2013 I just wanted to give a big thanks to John for fixing this problem with my amp. He got it up and running in no time and was also kind enough to change the speakers post for me. If anyone in the future has any issues with vintage stuff I strongly recommend you get it touch with him, his knowledge and attitude is first class. 1
skippy124 Posted January 19, 2013 Posted January 19, 2013 Hi Darren, Thank for the thanks and recommendation, it is much appreciated. Glad to hear that the unit arrived back safely and that you are happy with the speaker binding post upgrade. All that is left to say is.... enjoy the music!! Cheers John 4
Bassnutt Posted January 20, 2013 Posted January 20, 2013 I just wanted to give a big thanks to John for fixing this problem with my amp. He got it up and running in no time and was also kind enough to change the speakers post for me.If anyone in the future has any issues with vintage stuff I strongly recommend you get it touch with him, his knowledge and attitude is first class. Glad its up and running Darren hope it sounds nice and John did a great job on those speaker outputs I am going to do the same on any other one I find broken from now on, anyways enjoy your amp and sorry about all the problems.Cheers!
DAMO 1147 Posted January 20, 2013 Posted January 20, 2013 Great stuff-Glad to see it's all worked out and up and running- Sending a little 101 for a check up this week.
Dasher Posted January 20, 2013 Author Posted January 20, 2013 Glad its up and running Darren hope it sounds nice and John did a great job on those speaker outputs I am going to do the same on any other one I find broken from now on, anyways enjoy your amp and sorry about all the problems.Cheers! Hi Butch, Nice to see you here, no problem thanks for your help getting it all sorted. If I ever get my stupid music PC working again I might get a chance to play with my new amp. Great stuff-Glad to see it's all worked out and up and running- Sending a little 101 for a check up this week. I will be interested in your thoughts on the 101 and the Zu's.
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