Inlet Power Switch Choice

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Per Tom’s post #17 above, I think that was part of the reason he had to “switch” from the illuminated front panel panel switch as originally intended on his Mod286 kit to the rear panel fused / switched IEC power inlet - which works perfectly fine. To be honest, I’m one lazy and I guess profligate mofo, and don’t bother with the reach around to power the amp down when not listening. I justify to myself that the amp’s “vampire” standby power consumption is only one of literally dozens of such appliances around a modern “connected” home - the fridge being probably the worst culprit?
Who among us would have the patience to wait for the CPU in every single smart appliance to reboot for each use? Even when starting from power standby mode, it takes the receiver and smart TV in my home theatre system the best part of 30 seconds to fully synch up.
I know, “First world problems”:eek:
 
Per Tom’s post #17 above, I think that was part of the reason he had to “switch” from the illuminated front panel panel switch as originally intended on his Mod286 kit to the rear panel fused / switched IEC power inlet - which works perfectly fine. To be honest, I’m one lazy and I guess profligate mofo, and don’t bother with the reach around to power the amp down when not listening. I justify to myself that the amp’s “vampire” standby power consumption is only one of literally dozens of such appliances around a modern “connected” home - the fridge being probably the worst culprit?
Who among us would have the patience to wait for the CPU in every single smart appliance to reboot for each use? Even when starting from power standby mode, it takes the receiver and smart TV in my home theatre system the best part of 30 seconds to fully synch up.
I know, “First world problems”:eek:

Hi Chris,

I totally understand. I suppose I am faced with two options: have a switch on the back, or have a switch on the front. I will be using a 4" Waveshare LCD screen so the front face of the amp will have the screen and a volume knob.

I also plan on building the amplifier out of wood (probably Olive) so there is a specific look I am going for. I am thinking that the front will look better being simple: the screen offset to the left and the volume to the right. I am not sure having a switch on the front will look that good, but perhaps I can be persuaded.

Thank you
 
Olive wood is pretty. It must smell heavenly when machined. Sounds like a fun build.

The selection of mains-compatible switches is pretty limited. If you want something that looks nice and can handle the inrush current, you'll quickly find yourself with only a few choices, if any at all.
One way to expand the number of choices is to use a low-voltage switch and some electronics to turn the mains voltage on. That's one reason I designed the ISS (Intelligent Soft Start) to support the use of low-voltage switches. Using a low-voltage switch would allow you to use a type that just has a stem rather than a full button and add your own (turned olive wood) button to it. That could be made to look quite nice.

Making the mains switch survive the inrush current indeed drove the choice of the mains switch in the MOD286 Kit.

Tom
 
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Just jump on Mouser and search for "IEC inlet". Narrow it down to power inlets, and then use the filter function to include the features you want. Select a screw-mount type rather than a snap-in type. The snap-in types are pretty picky about the mounting panel thickness.

Tom

Would this switch/fuse/power inlet be a good choice?

4304.6058 Schurter | Mouser Canada

Will the switch handle the inrush current?

Thank you,

David.
 
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This one costs quite a bit less

763-00/001 Qualtek | Mouser Canada

It includes a switch rated for 10 amperes, same as the Schurter.

If you care what textbook authors have to say, both Douglas Self ("Audio Power Amplifier Design") and Rod Elliott (westhost) assert that inrush protection isn't really needed when the power transformer is rated 400 VA or less. On the other hand, even if you don't strictly need it, how can it hurt? If you want it, you want it.

Here is an inrush limiter PCB whose manufacturing CAD files ("Gerbers") are stored on diyAudio; you can download them for free, and send them off to a PCB fab in China to have ten boards made. Its on/off front panel switch operates at 5 volts DC & 1 milliampere, allowing a great variety of switch types. The Forum thread shows several diyAudio members who have already ordered PCBs this way, and are selling off their excess boards to others at cost. The guy in Germany, for example, is asking 10€ each pcb: (link)

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