I'm going to build a portable stereo boombox based on the Overnight Sensation speakers using a HiFiMeDIY T1-M and building my own crossovers as per the Overnight Sensation build.
My question is this: How would you handle the following?
I've been coursing through 2-way input selector threads, but haven't found any clever way to incorporate a single LED to one of the input sources so it switches on the power to the bluetooth board AND the snazzy blue LED.
Would a 'Ceramic Rotary Switch 4P3T 4 Pole 3 Throw' unit like this one do the trick? I'd have a 'free' position on the knob I assume, plus it's going to be used for low power audio signal so I don't want noise or artefacts in the 'click' action...
I'm in Oz so I'll be buying off eBay I'd presume.
Can anyone suggest a simple elegant solution to this conundrum? Thanks for any assistance fellas.
My question is this: How would you handle the following?
- I want two input sources - a Sure apt-x bluetooth board and standard RCA
- When Bluetooth input is selected I want to wire a single blue LED to switch on, along with the power to the bluetooth board. Switching to RCA input will powerdown the bluetooth and the blue LED will extinguish
- I would prefer a rotary selector (as I want a nice matching anodized knob to the volume control....) but will work with a rocker switch (2 position I guess) if it's cheaper or easier
I've been coursing through 2-way input selector threads, but haven't found any clever way to incorporate a single LED to one of the input sources so it switches on the power to the bluetooth board AND the snazzy blue LED.
Would a 'Ceramic Rotary Switch 4P3T 4 Pole 3 Throw' unit like this one do the trick? I'd have a 'free' position on the knob I assume, plus it's going to be used for low power audio signal so I don't want noise or artefacts in the 'click' action...
I'm in Oz so I'll be buying off eBay I'd presume.
Can anyone suggest a simple elegant solution to this conundrum? Thanks for any assistance fellas.
I found a solution - then disregarded it.
This board would completely do the job: Audio Signal Selector Relay Board Signal Amplifier Switching Board | eBay
However I'm only using two inputs so a simple DPDT switch will both power the bluetooth board and give me a status LED when the switch is engaged to that polarity.
BTW, the final product should look something like this.
Enclosure will be MDF, I have some Australian spotted gum veneer on the way from a local supplier...
This board would completely do the job: Audio Signal Selector Relay Board Signal Amplifier Switching Board | eBay
However I'm only using two inputs so a simple DPDT switch will both power the bluetooth board and give me a status LED when the switch is engaged to that polarity.
BTW, the final product should look something like this.
Enclosure will be MDF, I have some Australian spotted gum veneer on the way from a local supplier...
It sounds like you need a 2-pole 2-way rotary switch (or 3-pole for stereo). One pole to switch the audio (two for stereo), one pole to switch the supply (from which the LED will be fed too via a resistor).
To avoid clicks ensure that the signal poles only switch signal. This means coupling caps (if missing from the source/load) and ground leak resistors (ditto).
To avoid clicks ensure that the signal poles only switch signal. This means coupling caps (if missing from the source/load) and ground leak resistors (ditto).
Hi,
You can connect the two inputs with no switching
into a simple mixer type passive connection.
The Bluetooth board has a status LED and I assume
power management too, i.e. it defaults to just enough
low power (10mA) in static mode to detect Bluetooth.
rgds, sreten.
FWIW the 3.5mm audio out of the board can drive
headphones, and your other input for a portable
boombox should also be 3.5mm, not a RCA type.
This affects the best choice of the power amplifiers
input impedance, which basically can be quite low,
but with 47K input impedance doesn't need to be.
4.7K is series with all inputs to L+R will be fine.
You can connect the two inputs with no switching
into a simple mixer type passive connection.
The Bluetooth board has a status LED and I assume
power management too, i.e. it defaults to just enough
low power (10mA) in static mode to detect Bluetooth.
rgds, sreten.
FWIW the 3.5mm audio out of the board can drive
headphones, and your other input for a portable
boombox should also be 3.5mm, not a RCA type.
This affects the best choice of the power amplifiers
input impedance, which basically can be quite low,
but with 47K input impedance doesn't need to be.
4.7K is series with all inputs to L+R will be fine.
Last edited:
Thanks Sreten, I'd completely overlooked the 3.5 mm output on the board. Good pickup.
However I'm a little confused about input impedance. If I wired rca like you would a mini jack to rca cable with the negative joined at the input source wouldn't that behave the same as a 3.5mm input? I can't think if any other way to handle it.
I'm struggling to remember my audio electronics theory. I asked a few people at work today but they are software engineers and tended to agree with my logic.
This is great BTW.
I'm hoping to understand your comment about 47k vs 4.7 k input impedance.
However I'm a little confused about input impedance. If I wired rca like you would a mini jack to rca cable with the negative joined at the input source wouldn't that behave the same as a 3.5mm input? I can't think if any other way to handle it.
I'm struggling to remember my audio electronics theory. I asked a few people at work today but they are software engineers and tended to agree with my logic.
This is great BTW.
I'm hoping to understand your comment about 47k vs 4.7 k input impedance.
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