bf245b transistor orientation/chip protection

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Hi, I am building this sp/dif buffer as suggested on the Lampizator site the schematic is on the page
CD Transport Digi-Lampizator
An externally hosted image should be here but it was not working when we last tested it.

It is a simple question :do I have the flat side of the "D" facing the signal wire ????? I take it the sp/dif signal enters the transistor on the centre pin.....It is not that I am too lazy to experiment , I am just worried wrong orientation would blow the signal generator chip or something nasty and the Quad 99 I am using is made of very very flimsy parts , I think it would be hard to repair..Thanks Alan...
ps if I am worried about blowing chips can you protect them by using a diode in series along the signal wire??
this is the pin configuration of the bf245b, signal enters in G pin, which is at bottom looking at D


  • piedinatura_bf245.jpg
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still confused

Tfan69....does the power come in on the "s" or "d" pin then??????.....sorry for being so thick...

Luke .....I have no idea I was just going to connect it and see what happens....I do not even know what spdif generating chip I have ...all I know is is that a stock quad 99 is a very very poor affair indeed and needs all the help it can get
0.3v dc

Hi, Tfan...I have built the buffer and am running it off a 9volt battery for a minute...its built as a external unit and plugs into the rear digital output socket on the player....and outputs to an external dac.... SO ....all rca grounds /battery ground and resistor grounds share the same rail........Before I plugged into the player , I put a multimeter on the output hot pin and found it is outputing 0.3volts DC before any sp/dif signal is applied....I was suprised to see the DC as I thought the 10 uf capacitor was supposed to block it....I have double checked everything and cannot see how I have varied from the is this an acceptable amount of dc to be going to the dac or have I indeed messed up??? I have not plugged the unit in as I am worried about the my grounding right?

its definately a 10uf non polar just a cheap brand...i have left the thing powered and now when I read the pin i see....0.02volts dc....could this be evidence of the so called "burn in" of a electrolytic???? is 0.02v safe for the dac? I will raid my parts bin attach a resistor like you said .....see what happens
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