If not very expensive I will try, thanks for all support to us and to develop always such a great products, I hate SMPS powering audio devices.
![IMG_20190401_155450[1].jpg](/community/data/attachments/693/693149-ca0613d70a3f4017b28f9bb1a9a664b4.jpg?hash=ygYT1wo_QB)
Does anyone have a recipe for 4v output voltage. I managed to get 4,6v with 2 orange kingbright leds and a jumper. I was aiming for as close to 4v as possible still staying above. I have green, red, yellow and orange on hand and one 1N4148.
Hmm.. maybe an orange and an infrared? Or a green and an infrared when bit short from target. If you haven't got any IR LED in hand, an old useless remote control could donate one.
Thanks 🙂
One of these should do it I guess.
https://www.mouser.se/Kingbright/Optoelectronics/Infrared-Data-Communications/Infrared-Emitters/_/N-6qrgl?P=1z0z63xZ1z139kbZ1z0ysu0Z1z0yt2p
One of these should do it I guess.
https://www.mouser.se/Kingbright/Optoelectronics/Infrared-Data-Communications/Infrared-Emitters/_/N-6qrgl?P=1z0z63xZ1z139kbZ1z0ysu0Z1z0yt2p
Yes, look at their datasheets there. There are forward current vs forward voltage curves. If its the 1k R6 resistor style REF-D you use, there are 2mA running in the Vref. If its a JFET mod then its almost IDSS of the individual 2SK. Maybe 20% less because the voltage threshold isn't the 10V IDSS test level across the FET but only near 2V. You want at that current in the LED curves, the colored LED VF + the IR LED VF + 1.22V residual from the mirror transistors Vbe to give 4V total.
It's jfet mod. The order is already sent, 1,2v, 1,3v, and 1,6v forward voltage according to the datasheet so it's trial and error in a week or so... Mouser are usually pretty fast.
P.S. Their forward voltage nominal is stated at 20mA so you will have a good variety of lesser than nominal VF to mix and match with colored LEDS at the circuit's much lower mA Vref running current.
You will have to calculate. If its a build with R6 1k then the Vref current is about 2mA. In that example 120 Ohm would bring 2mA*120 Ohm = 0.24V. If its JFET mod and you aren't sure about the exact Vref current, the 10 Ohm will develop a drop that will show the way. If it is 0.4V then 4mA is running. So 62 Ohm would bring 0.248V extra.
I don't have any digital SPDIF source to try, tomorrow comes at home Antonio with a CD transport or streaming with SPDIF output to try, I will keep informed.