Hi guys
This is my first real post here; forgive me asking rather that answering a question, I have very little knowledge regarding electronics but I am willing to learn and pass on what I’ve learned.
I’m in need of some advice regarding an issue with my Sansui AU101 amplifier. The speaker switching switch is defective; I need to wiggle it up and down just to get music to come out and then jam-it in that position hoping music will remain (it doesn’t normally which is a pain).
I purchased the amplifier in this condition (due to cost constraints) thinking I could easily fix it, but I have failed to source any information that may help. I also intended to use it as a electronics learning project.
When music does come out it is surprising good, big soundstage and an overall smoothness, what else has amazed me is the power, I believe it has 15 watts but sounds way more powerful with my speakers (Goodmans magnum Ks 1964 model),easily fills my 25x12ft living room.
Does anyone know if I can source an alternative replacement or would it be possible to take it out of the circuit completely.
I’ve included some pics below of the Sansui AU101 and the problematic switch.
Appreciate any help you can give me
Dean
This is my first real post here; forgive me asking rather that answering a question, I have very little knowledge regarding electronics but I am willing to learn and pass on what I’ve learned.
I’m in need of some advice regarding an issue with my Sansui AU101 amplifier. The speaker switching switch is defective; I need to wiggle it up and down just to get music to come out and then jam-it in that position hoping music will remain (it doesn’t normally which is a pain).
I purchased the amplifier in this condition (due to cost constraints) thinking I could easily fix it, but I have failed to source any information that may help. I also intended to use it as a electronics learning project.
When music does come out it is surprising good, big soundstage and an overall smoothness, what else has amazed me is the power, I believe it has 15 watts but sounds way more powerful with my speakers (Goodmans magnum Ks 1964 model),easily fills my 25x12ft living room.
Does anyone know if I can source an alternative replacement or would it be possible to take it out of the circuit completely.
I’ve included some pics below of the Sansui AU101 and the problematic switch.
Appreciate any help you can give me
Dean
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Shame about the damage to what is a clean lines, good looking old amp. (I have one around here somewhere too!) Maybe someone with a wreck of one of that early series can help out, since they were very affordable and popular models back in the early 1970s.
The switch only disconnects the speakers when you want to use headphones alone. This is a very old solid state amp without the fancier features like relays and switched 'phone socket so, as you can see in your own pic, the headphone connections (those 330R resistors on flying leads) are permanently wired to the amplifier outputs (the wires to the centre pins of the switches) The other (lower) wires will connect the outputs to the speaker terminals when the switch is in the on (up) position.
Surely you can still manipulate the switch into the on position and leave it there. I guess though, if the whole toggle pivot is also smashed, you will just have to bridge the upper and lower wire connections on either side and that does the same job as the switch contacts in the on position. Use short lengths of solid tinned copper wire, top to bottom on either side there - it doesn't have to be thick wire for that short run either. So, join blue to black, grey(?) to white. That's all.
Hope this is helpful and take care.
The switch only disconnects the speakers when you want to use headphones alone. This is a very old solid state amp without the fancier features like relays and switched 'phone socket so, as you can see in your own pic, the headphone connections (those 330R resistors on flying leads) are permanently wired to the amplifier outputs (the wires to the centre pins of the switches) The other (lower) wires will connect the outputs to the speaker terminals when the switch is in the on (up) position.
Surely you can still manipulate the switch into the on position and leave it there. I guess though, if the whole toggle pivot is also smashed, you will just have to bridge the upper and lower wire connections on either side and that does the same job as the switch contacts in the on position. Use short lengths of solid tinned copper wire, top to bottom on either side there - it doesn't have to be thick wire for that short run either. So, join blue to black, grey(?) to white. That's all.
Hope this is helpful and take care.
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I'd go along with Ian's suggestion too. If you have the broken bit then I'm sure it will glue back on with the tiniest drop of superglue. At least that would maintain the appearance.
I wonder whether it would be worth removing the broken switch and flooding it with WD40, it just might clean up OK.
I wonder whether it would be worth removing the broken switch and flooding it with WD40, it just might clean up OK.
“Hope this is helpful” are you kidding? I am so grateful for your reply and comprehensive Information/advice to the problem; to be honest I wasn’t expecting any reply (shame on me for doubting).
Your advice is clear and precise Ian and it’s within my capability, so I’m so grateful for it.
I will look forward to having a go soon, would you mind if I placed a picture of what I’m doing on here so that you can have a check that I’ve done it correctly.
“Surely you can still manipulate the switch into the on position and leave it there”
Unfortunately I think the switch itself has failed (I will try some WD40 as suggested by Mooly), it will not play ball in any position for long.
Thank you once again Ian you have been a great help
Thank you for your input Mooly
Unfortunately I haven't got the piece that snapped off, I guess I could try and make something up
I've got some WD40 so I will have a try thanks.
Thanks again Guys
All the best
Dean
PS will report back soon.
Your advice is clear and precise Ian and it’s within my capability, so I’m so grateful for it.
I will look forward to having a go soon, would you mind if I placed a picture of what I’m doing on here so that you can have a check that I’ve done it correctly.
“Surely you can still manipulate the switch into the on position and leave it there”
Unfortunately I think the switch itself has failed (I will try some WD40 as suggested by Mooly), it will not play ball in any position for long.
Thank you once again Ian you have been a great help
Thank you for your input Mooly
Unfortunately I haven't got the piece that snapped off, I guess I could try and make something upI've got some WD40 so I will have a try thanks.
Thanks again Guys
All the best
Dean
PS will report back soon.
Pictures are good 🙂
A real long shot but if the screw holes are 19mm apart then something like this might fit. Its not ideal, and its only rated at half an amp, but hey, its only a 15 watt amp and your not likely to be actually operating the switch at full volume anyway. Just a thought.
SLIDE SWITCH MINIATURE DPCO - -- - SLIDE SWITCH, DPDT, GREY, PK10 | CPC
A real long shot but if the screw holes are 19mm apart then something like this might fit. Its not ideal, and its only rated at half an amp, but hey, its only a 15 watt amp and your not likely to be actually operating the switch at full volume anyway. Just a thought.
SLIDE SWITCH MINIATURE DPCO - -- - SLIDE SWITCH, DPDT, GREY, PK10 | CPC
Since the paddle switch mounts to a sub-panel, you could adapt something to fit, as there are few, if any products still readily available in that mounting format. (I think Mooly has found it! ) For interest, here's a locally available variant of a common universal switch: Altronics - S1250 DPDT Solder Tail Mini Paddle Switch .
It does have a black, flat paddle actuator, dimensions shown but probably won't fit simply. In the 537 web pages of switches in the Mouser catalogue, you find all sorts - here's some C&K brand datasheets: http://www.mouser.com/ds/2/60/7000rockers_13dec11-16314.pdf
Measure up and think about it. It could still be surprisingly easy once you have something that works. Just ensure it's a double pole type (DPST or DPDT) and the arc of movement will swing wide enough to function. The original swings from level to ~30 deg. down IIRC. This will be unobtanium but available types may still operate by adjusting mounting position.
I would just slip a piece of dull black card or plastic in there to obscure the old switch and ignore it. It's going nowhere and at the low power, isolated by its output capacitor, shouldn't give cause for concern. 🙂
It does have a black, flat paddle actuator, dimensions shown but probably won't fit simply. In the 537 web pages of switches in the Mouser catalogue, you find all sorts - here's some C&K brand datasheets: http://www.mouser.com/ds/2/60/7000rockers_13dec11-16314.pdf
Measure up and think about it. It could still be surprisingly easy once you have something that works. Just ensure it's a double pole type (DPST or DPDT) and the arc of movement will swing wide enough to function. The original swings from level to ~30 deg. down IIRC. This will be unobtanium but available types may still operate by adjusting mounting position.
I would just slip a piece of dull black card or plastic in there to obscure the old switch and ignore it. It's going nowhere and at the low power, isolated by its output capacitor, shouldn't give cause for concern. 🙂
Hi Guys
I've gone ahead and bridged the upper and lower wire connections on either side.Could you please confirm that I've done it correctly before I switch the amp on.I appreciate you can't judge my soldering but I guess I'll know if it's not good enough😱.
Here's the pic.
Thanks for suggesting and doing some research on a new switch (I would prefer a new one).I've found one on ebay,could you tell me if this is suitable please.
I 'm sorry I can't seem to copy & paste the link.Here's the item number
eBay item number:
330826001416
The width between the screw holes on the amp is 35mm ,the one on ebay is 24mm so I'll have to adapt.
Guys I really appreciate all your help
all the best
Dean
I've gone ahead and bridged the upper and lower wire connections on either side.Could you please confirm that I've done it correctly before I switch the amp on.I appreciate you can't judge my soldering but I guess I'll know if it's not good enough😱.
Here's the pic.
An externally hosted image should be here but it was not working when we last tested it.
Thanks for suggesting and doing some research on a new switch (I would prefer a new one).I've found one on ebay,could you tell me if this is suitable please.
I 'm sorry I can't seem to copy & paste the link.Here's the item number
eBay item number:
330826001416
The width between the screw holes on the amp is 35mm ,the one on ebay is 24mm so I'll have to adapt.
Guys I really appreciate all your help
all the best
Dean
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Good work, the switch wiring looks OK. Give the black wire a tug with the pliers to be sure.
Unfortunately, the replacement you found has too much bulk located forward of its mounting plate and I guess the paddle will be much narrower. To get it to work, you would need spacing blocks or perhaps tiny, hand made sheet metal "Z" brackets to locate it about 12 mm further behind the sub panel. There is little on the original switch, other than the paddle itself, protruding forward of the plate and this is the difficult requirement, not forgetting to add some vertical offset (lower it) for the different arc of paddle movement.
'Not impossible for a fixit kind of guy but an awkward set of specs. Good luck but meanwhile, enjoy the amp!
Unfortunately, the replacement you found has too much bulk located forward of its mounting plate and I guess the paddle will be much narrower. To get it to work, you would need spacing blocks or perhaps tiny, hand made sheet metal "Z" brackets to locate it about 12 mm further behind the sub panel. There is little on the original switch, other than the paddle itself, protruding forward of the plate and this is the difficult requirement, not forgetting to add some vertical offset (lower it) for the different arc of paddle movement.
'Not impossible for a fixit kind of guy but an awkward set of specs. Good luck but meanwhile, enjoy the amp!
As above really 🙂
There are options but all involve a bit of diy of some sort. I guess the real question is whether the use of headphones is needed. If not then just accept it as it is and perhaps blank the hole off.
There are options but all involve a bit of diy of some sort. I guess the real question is whether the use of headphones is needed. If not then just accept it as it is and perhaps blank the hole off.
Unfortunately Mooly gave a bad advice 😡
As the WD 40 is a little oily and it's NOT the right product to polish the contacts. You must find a cleaner that evaporates rapidly; a mechanical removing ( tissues, ear sticks ?!? ) of the dirt goes together with the spray.
About the switch, I wouldn't have bothered more : a hole on the front panel
doesn't impress me as long the cable redundancy and added resistance associated with it have been removed ---as the HP output.
Hi Ian,
I gave the wire a tug seems pretty secure. I’m grateful for you taking the time to look at the switch on eBay, I was quite excited when I seen it, never mind, I’m just grateful for your advice,I would have wasted my money, I didn’t have much of an idea.
I'm going to try the amp today.
Thanks once again for all your help
ps if I come across another switch ,may I contact you for advice please.
Hi Mooly,
Ideally I would like to keep the option of using headphones (my quest will continue for a switch ), but for now I’m just grateful to have music through my speakers (hopefully).
Hi Picowallspeaker,
Thanks for your input. I didn’t have any WD40 afterwards so I guess that was a good thing😕. I’ve read about this Deoxit stuff but price wise it’s way out of my league.
I was wondering if I could use Isopropanol (I use a mix of this to clean my records).I know it evaporates quickly but would it have any cleaning effect and would it be safe on electronics.
I want to clean all the Switches and controls on the amplifier .What is the best way?
Guys I can’t wait to try this amplifier ,so I’ll shoot off and report back later on this evening.
All the Best
Dean
I gave the wire a tug seems pretty secure. I’m grateful for you taking the time to look at the switch on eBay, I was quite excited when I seen it, never mind, I’m just grateful for your advice,I would have wasted my money, I didn’t have much of an idea.
I'm going to try the amp today.
Thanks once again for all your help
ps if I come across another switch ,may I contact you for advice please.
Hi Mooly,
Ideally I would like to keep the option of using headphones (my quest will continue for a switch ), but for now I’m just grateful to have music through my speakers (hopefully).
Hi Picowallspeaker,
Thanks for your input. I didn’t have any WD40 afterwards so I guess that was a good thing😕. I’ve read about this Deoxit stuff but price wise it’s way out of my league.
I was wondering if I could use Isopropanol (I use a mix of this to clean my records).I know it evaporates quickly but would it have any cleaning effect and would it be safe on electronics.
I want to clean all the Switches and controls on the amplifier .What is the best way?
Guys I can’t wait to try this amplifier ,so I’ll shoot off and report back later on this evening.
All the Best
Dean
Isopropanol is used in normal electronics cleaner bottles, so yes, it is definitely safe and useful here.
Some lubrication afterward is a good thing, though. Wd 40 will do the trick but I hate the stink of it so I wouldn't use it myself. 🙂
Some lubrication afterward is a good thing, though. Wd 40 will do the trick but I hate the stink of it so I wouldn't use it myself. 🙂
You have options to retain the headphone output 🙂
Do you know how a relay works ? Its really just like the switch except that its operated electrically. You could feed the speaker output through a relay and have a small switch (pretty much anything of any type if it was physically suitable) and the switch would then operate the relay when you wanted just h/phones.
WD40... I know many don't like this, but over the years as a repair tech I've used many dedicated "switch cleaners" and seen many problems. Electrolube and Servisol were the engineers standard kit. Trouble was, weeks and months later the equipment often had to be written off due to "plastic rot" whereby any plastic casework etc assumed the consistency of the icing you get on cakes. Flex it and it just cracked and crumbled. And that was the dedicated trade switch cleaners.
Do you know how a relay works ? Its really just like the switch except that its operated electrically. You could feed the speaker output through a relay and have a small switch (pretty much anything of any type if it was physically suitable) and the switch would then operate the relay when you wanted just h/phones.
WD40... I know many don't like this, but over the years as a repair tech I've used many dedicated "switch cleaners" and seen many problems. Electrolube and Servisol were the engineers standard kit. Trouble was, weeks and months later the equipment often had to be written off due to "plastic rot" whereby any plastic casework etc assumed the consistency of the icing you get on cakes. Flex it and it just cracked and crumbled. And that was the dedicated trade switch cleaners.
I have a switch for this amp, kind of spare, I'm just over in Liverpool. Drop a line if you still seeking
Ah yes, the joys of CFC cleaning and freezing products. The industry and service product distributors put constant pressure on service organisations to use these rather than WD40, CRC 5-56 etc. I recall the white papers, sales BS and waffle at the time specialist distributors were trying to expand this narrow market sector.
Sure, there are valid technical reasons to prefer dedicated products for high reliabilty relays, low contact presure, low sulphur contamination etc. Then there's the stink of WD's diesel fuel base, some products "deodorised", others, the masking odour is worse. More generally, given the greedy profit margins in this narrow market sector, we can understand why distributors energetically promote it. Even so, the dedicated solvent cleaners obviously weren't tested fully on products under regular service conditions. The switch to hydrocarbon solvents should have changed this, though.
At 20 UKP for 5 litres of the WD concentrate, you come to realise the basic nature of the product - you could fuel your diesel on it!😀 At least WD spray will be somewhere in reach for DIYs when they need it. If there is later doubt, its not difficult to flush any remnant away with your preferred product. (when you can find/afford it
)Oh yeah - I knew this guy who even used WD on his vinyl collection to kill the clicks and scratches?.....true! 😱
Hi Welcome
Thanks for your input.
I agree with you regarding the smell it’s way to pungent and it doesn’t really disperse enough.
Hi Mooly,
I’m not sure I fully understand. I’m a complete beginner, so I wouldn’t feel comfortable with doing that “yet”. Thanks for making the effort to explain though😉.
WD40 or not ? it’s confusing to say the least. I’ve used it quite effectively on all sorts of things (outdoors) but not on electronics . I really dislike the smell so I guess I’ll stick to Isopropanol for now until I do more research on the subject.
I’ve cleaned the volume control with Isopropanol and there’s no crackles now so I'll leave it at that for the moment.
Hi mikstick,
Thanks for the offer. I’ll be sending you a PM shortly.
Hi Ian
Thank you for enlightening me
I know very little about these products and I can see this cleaning stuff is full of controversy, but it’s not surprising it’s just one of “many” things in the market place that sometimes gets the “holy grail” seal of approval only to be found out that the products are a “pig-in-a-poke” .Most of the market place is spurned on by greed and corruption, but I still believe that there “are” genuine people out there trying to make things better. It’s just that they lay the shadow of the big corporations and very rarely see the light of day unless there’s big money to be made , or am I being too cynical.
I’ve decided to rule out WD40 due to the smell. Will do more research into these types of products.
The amplifier is working/sounding fine, there is a “thump” on switch on, is this common.
We (my mate and I) had a good few hours of playing music yesterday.The sound was quite surprising, very smooth and dynamic and more than enough power to drive his ARs. Compared to my mates resident Arcam amplifier it sounded more immediate but not forward sounding, vocals were prominent and were easily understood. We tried several cds, first up was some Robbie Robertson the whole presentation was larger than we’re used too, his voice was clean and clear. Pink Floyd The Wall was next, Nick masons drumming sounded much tighter and again the presentation was big and bold ! not what we expected from a 15watt amplifier.
We played some Norah Jones and some Yello even though we’re Vinyl enthusiasts; and very rarely play cds, the Sansui made them more enjoyable than the Arcam😕
We didn’t get round to playing vinyl so I don’t know how good the phono stage is.My mates system consist of a NAD CD-player, Techinic 120 Turntable/Jelco Tonearm/Grado Gold moving magnet cartridge and some Acoustic Research speakers on stands, the room is about 10x15ft with lots of soft furnishings.
I’m very pleased at the performance of such an old amplifier; we were surprised at the level of detail we heard from every recording that we tried.
I’ve heard valve amplifiers in the past (tried them in my system) and the Sansui sound is not to dissimilar in my book, it has a good mid-range, its sound is big and quite airy and is smoother sounding than many Solid state amplifier that we’ve heard.
I know its all subjective , but I do question; after listening to this Sansui, how much better today’s Hi-Fi really is compared to the older stuff. Well, in our humble opinion it’s no better, just different😀.
The Sansui is still with my mate at the moment, he enjoyed it so much that he loathed to go back to the Arcam so I left it with him.
If anyone is interested, I’ll give my opinion of how it sounds with my system playng Vinyl. My room is a lot bigger, I have a Suspended belt drive turntable and some Goodmans Speakers from the 60s.
Once again, I want to thank everyone for contributing to my thread and especially Ian,without your help the Sansui would be sitting in my attic gathering dust.
Cheers Guys
Dean
Thanks for your input.
I agree with you regarding the smell it’s way to pungent and it doesn’t really disperse enough.
Hi Mooly,
I’m not sure I fully understand. I’m a complete beginner, so I wouldn’t feel comfortable with doing that “yet”. Thanks for making the effort to explain though😉.
WD40 or not ? it’s confusing to say the least. I’ve used it quite effectively on all sorts of things (outdoors) but not on electronics . I really dislike the smell so I guess I’ll stick to Isopropanol for now until I do more research on the subject.
I’ve cleaned the volume control with Isopropanol and there’s no crackles now so I'll leave it at that for the moment.
Hi mikstick,
Thanks for the offer. I’ll be sending you a PM shortly.
Hi Ian
Thank you for enlightening me
I know very little about these products and I can see this cleaning stuff is full of controversy, but it’s not surprising it’s just one of “many” things in the market place that sometimes gets the “holy grail” seal of approval only to be found out that the products are a “pig-in-a-poke” .Most of the market place is spurned on by greed and corruption, but I still believe that there “are” genuine people out there trying to make things better. It’s just that they lay the shadow of the big corporations and very rarely see the light of day unless there’s big money to be made , or am I being too cynical.
I’ve decided to rule out WD40 due to the smell. Will do more research into these types of products.
The amplifier is working/sounding fine, there is a “thump” on switch on, is this common.
We (my mate and I) had a good few hours of playing music yesterday.The sound was quite surprising, very smooth and dynamic and more than enough power to drive his ARs. Compared to my mates resident Arcam amplifier it sounded more immediate but not forward sounding, vocals were prominent and were easily understood. We tried several cds, first up was some Robbie Robertson the whole presentation was larger than we’re used too, his voice was clean and clear. Pink Floyd The Wall was next, Nick masons drumming sounded much tighter and again the presentation was big and bold ! not what we expected from a 15watt amplifier.
We played some Norah Jones and some Yello even though we’re Vinyl enthusiasts; and very rarely play cds, the Sansui made them more enjoyable than the Arcam😕
We didn’t get round to playing vinyl so I don’t know how good the phono stage is.My mates system consist of a NAD CD-player, Techinic 120 Turntable/Jelco Tonearm/Grado Gold moving magnet cartridge and some Acoustic Research speakers on stands, the room is about 10x15ft with lots of soft furnishings.
I’m very pleased at the performance of such an old amplifier; we were surprised at the level of detail we heard from every recording that we tried.
I’ve heard valve amplifiers in the past (tried them in my system) and the Sansui sound is not to dissimilar in my book, it has a good mid-range, its sound is big and quite airy and is smoother sounding than many Solid state amplifier that we’ve heard.
I know its all subjective , but I do question; after listening to this Sansui, how much better today’s Hi-Fi really is compared to the older stuff. Well, in our humble opinion it’s no better, just different😀.
The Sansui is still with my mate at the moment, he enjoyed it so much that he loathed to go back to the Arcam so I left it with him.
If anyone is interested, I’ll give my opinion of how it sounds with my system playng Vinyl. My room is a lot bigger, I have a Suspended belt drive turntable and some Goodmans Speakers from the 60s.
Once again, I want to thank everyone for contributing to my thread and especially Ian
,without your help the Sansui would be sitting in my attic gathering dust.Cheers Guys
Dean
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Hearing you say how good it sounded made me look up the circuit. Its a classic 6 transistor (per channel) design, AC coupled (so that's something to look at in future, replacing old caps) with a single ended input stage. This type of design can truly excel sonically, even if the raw numbers aren't too impressive by todays standards. It is my "basic configuration" of choice for power amplifier designs.
The switch on thump is normal I'm afraid. You could overcome that with a relay 😀 for the speaker feed by incorporating a switch on delay.
The switch on thump is normal I'm afraid. You could overcome that with a relay 😀 for the speaker feed by incorporating a switch on delay.
Hi Mooly
I'm sorry most of that means very little to me😕 maybe one day uh! 😉 but I may be up for changing capacitors
😀.I'll make a new thread if I decide to do it.What benefits would the amp gain in terms of sound quality and would you be willing to help me through it.Thanks for letting me know about the "thump" puts my mind to rest.
Cheers
Dean
Replacing old electrolytic caps is generally straightforward... and yes if you decide you want to have a go then myself (and I'm sure others too) would offer advice. Biggest "problem" and its not really a problem at all, is actually looking at the physical size of the caps first and making sure what you replace them with fit neatly. Nothing worse than parts with wires and bent leads being "made" to fit 😀 You want it to be just like new...
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