Concept 16.5 power switch
- Thread starter himm37
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Himm37, I cannot help with the power switch. However, there is a Concept Audio forum on Yahoo where several ex Pacific Stereo techs are active members, and where some members may even have spare parts units. You may want to try posting there.
On a separate topic, I maintain a database of Concept receiver serial numbers (linked to from my signature). Would you mind contributing yours? Thanks:thmbsp:.
Good luck on getting that switch fixed.
All the best,
Hi, if you can, please try to provide a photo of the switch and any relevant dimensions and whether its screw or pc mounted. Also, if you can identify any model or ratings on the switch, that would also be helpful in finding a substitute or replacement.
Regards,
Bart
Regards,
Bart
himm37
Well-Known Member
NN, Looks like mine is the oldest one so far, Ser # 100071
Bart, I posted 2 pics: HERE & HERE
It's got a label on the end that says "Alps snap switch L 72" and the #'s SDU4P 7v 5 72 appear on the cover plate, one or two of the digits are hard to read and may be incorrect. If you look closely, you'll see the back, heavier duty section separates from the front light duty section. The front section is soldered and screwed to the PC board.
The good news about this design is that if I have to make something else work, the existing front part should maintain the original look and feel, I would just have to make sure the new switch aligns to the protruding section of the front switch.
I'm thinking of a different idea, and would like some opinions on this. The front section of this switch is a DPDT design, however only 1 leg of rear section is in use, the other two pins are connected to blank spots on the pc board. My idea is to use these two contacts to close a relay that would supply power to the two power supply leads. The 2 currently UNused contacts would only be drawing enough current to close the relay, they should be able to handle that with no trouble. This can be done fairly easy, all the wires I need are right there, there is plenty of room to mount a relay AND I can keep the original design by connecting to the existing PC board.
I believe this relay should work fine, it's 10 amp rated, (that would be 10 on each leg?) and the 16.5 uses two 7 amp fuses.
http://www.radioshack.com/product/i...ay&kw=relay&kwCatId=2032058&parentPage=search
Any Thoughts?
Bart, I posted 2 pics: HERE & HERE
It's got a label on the end that says "Alps snap switch L 72" and the #'s SDU4P 7v 5 72 appear on the cover plate, one or two of the digits are hard to read and may be incorrect. If you look closely, you'll see the back, heavier duty section separates from the front light duty section. The front section is soldered and screwed to the PC board.
The good news about this design is that if I have to make something else work, the existing front part should maintain the original look and feel, I would just have to make sure the new switch aligns to the protruding section of the front switch.
I'm thinking of a different idea, and would like some opinions on this. The front section of this switch is a DPDT design, however only 1 leg of rear section is in use, the other two pins are connected to blank spots on the pc board. My idea is to use these two contacts to close a relay that would supply power to the two power supply leads. The 2 currently UNused contacts would only be drawing enough current to close the relay, they should be able to handle that with no trouble. This can be done fairly easy, all the wires I need are right there, there is plenty of room to mount a relay AND I can keep the original design by connecting to the existing PC board.
I believe this relay should work fine, it's 10 amp rated, (that would be 10 on each leg?) and the 16.5 uses two 7 amp fuses.
http://www.radioshack.com/product/i...ay&kw=relay&kwCatId=2032058&parentPage=search
Any Thoughts?
Hi Himm,
thanks for the photos. Does this suggest this is a custom switch put together from two switches ganged together? Replacement sections that are at least 7A pushbutton swtiches should be reasonably plentiful IF one wants to just replace the switch. Problem is how to gang the front and back parts together.
I have always like the idea of using the primary power switch to actuate a heavy duty relay to switch the full power, just seems more robust and less worry about the switch having to carry really large current. Of course, on most receivers, space is limited and must fit into tight areas. With purpose built power amps, we usually see the big fat rocker switches which almost by design can carry lots more current.
Besides, who wants a printed circuit board trace to carry 7A or more of current?
Have an idea about the circuit and relay layout?
Regards,
Bart
thanks for the photos. Does this suggest this is a custom switch put together from two switches ganged together? Replacement sections that are at least 7A pushbutton swtiches should be reasonably plentiful IF one wants to just replace the switch. Problem is how to gang the front and back parts together.
I have always like the idea of using the primary power switch to actuate a heavy duty relay to switch the full power, just seems more robust and less worry about the switch having to carry really large current. Of course, on most receivers, space is limited and must fit into tight areas. With purpose built power amps, we usually see the big fat rocker switches which almost by design can carry lots more current.
Besides, who wants a printed circuit board trace to carry 7A or more of current?
Have an idea about the circuit and relay layout?
Regards,
Bart
himm37
Well-Known Member
I don't know if it's a custom switch, I'm assuming it's original, possibly custom made for Concept.
As for the circuit and layout, I would bring 110 to one leg of the switch, and have it supply the relay coil in the on (closed) position with the other end of the relay coil to -. From there it's a simple matter of taking the existing power in and out wiring from the bad part of the switch and transfering them to the relay contacts. I would probably just jumper to the connections on the small PC thats attached to the bad switch. This would leave the capacitors in the circuit, and since the old switch is gutted, there is no worry of :
"backfeeding" anything.
BTW, I'm no tech by any means, but I'm very comfortable with basic stuff like this. I was Factory trained Auto Tech in the 80's and 90's and took advantage of all the training that was offered, including some college level courses. Tracing intermittent problems in those early "electrical messes" they were building was over the head of most old schoolers at the time!
As for the circuit and layout, I would bring 110 to one leg of the switch, and have it supply the relay coil in the on (closed) position with the other end of the relay coil to -. From there it's a simple matter of taking the existing power in and out wiring from the bad part of the switch and transfering them to the relay contacts. I would probably just jumper to the connections on the small PC thats attached to the bad switch. This would leave the capacitors in the circuit, and since the old switch is gutted, there is no worry of :
"backfeeding" anything.
BTW, I'm no tech by any means, but I'm very comfortable with basic stuff like this. I was Factory trained Auto Tech in the 80's and 90's and took advantage of all the training that was offered, including some college level courses. Tracing intermittent problems in those early "electrical messes" they were building was over the head of most old schoolers at the time!
MOPAR3
Super Member
That switch is not all that unique. It was used in NAD gear and probably some others as well. I'm on the look out for one also. Haven't had any luck yet. I'd like to start with a new switch and then set up the relay. In the NAD pre I have the front section switches a turn on muting circuit and the rear controls the power.
himm37
Well-Known Member
Hey Mopar, I haven't looked at the schematic yet to see what the front section on the Concept does, it looks like it heads into the tuner also, I'll look into that later. In any case it's a low power circuit, based on the wiring, and that part of the switch is good. The side of the switch I'll be using to power the relay is unused in the original Concept configuration so it is new.
`
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Yes, that is the earliest 16.5 recorded here by a long margin, and it lends support to our assumption that production numbers for the 16.5 (as it did for many, albeit not all, Concept receivers) started at 100000. So most likely, your unit is the #71 16.5 rolling off the production line at TCE in Japan.
On a separate point, you are aware that a 16.5 schematic is available from the Concept resources linked to from my signature, right?
All the best,
MOPAR3
Super Member
I don't understand why relays are not used more for current applications. I'm also an auto tech for Dodge. Small world. The switch in my NAD switches both sides of the power cord I think because the cord is not polarized so power can come in on either side. It would be nice to get a bolt in switch to keep things simple. My pre amp doesn't use much juice the only reason for the 5A switch is for the outlets on the back so I really don't need to add a relay. Have you had a chance to listen to the Concept much? is it new to you? I had never heard of Concept until I joined AK. I've never seen one here on the East coast. I'd grab any one of their line in second. Just cause its different and kind rare.
CharlieBee
Super Member
Will using a surge protector power strip to switch on and off the receiver and other related decks and turntable help take the load off the receiver on/off switch, possibly lengthening it life?
Charlie
Charlie
I know this is a necropost, but I'm interested in the fate of OP's 16.5...
Did you find a switch or just repair the old one? Or did you let it die...?
When searching for the part numbers OP listed, this page came up in the results:
http://parts.digikey.com/1/parts/966156-switch-pushbutton-dpst-7a-125v-p227ee1cxc.html
I have no idea how it got cross-referenced with the parts numbers OP listed, but it seems to be a replacement with the same specs. There seem to be some minimal differences, but it looks like it would drop right in.
I just picked up a 4.5 with major contact crud. Gonna have a go with dustoff and deoxit tomorrow and see what changes...
Did you find a switch or just repair the old one? Or did you let it die...?
When searching for the part numbers OP listed, this page came up in the results:
http://parts.digikey.com/1/parts/966156-switch-pushbutton-dpst-7a-125v-p227ee1cxc.html
I have no idea how it got cross-referenced with the parts numbers OP listed, but it seems to be a replacement with the same specs. There seem to be some minimal differences, but it looks like it would drop right in.
I just picked up a 4.5 with major contact crud. Gonna have a go with dustoff and deoxit tomorrow and see what changes...
