Mini Pearl

Resistor dissipation

R9, 499 Ohms - could be problematic if you use 0.100 Watt device.
 

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With respect to choice of the passives -- I am using Rohm -- but I don't think that there is going to be a critical effect to use -- in my box of SMT 0805's I have Panasonic, Vishay and Yageo.

I would suggest building the output stage first! Both the SMT and Through-Hole MOSFETs are very static sensitive.
 
These wee boards look amazing, thanks again Jack for your miniaturisation and Wayne too !

I’m in the UK trying to source some of the LSK389a and was referred onto Micross by Linear Systems but sadly Micross want me to place an order for a £250 minimum for 50 parts.

Anyone in Euro land found any better options ?

I may have to resort to my pal who is taking a holiday in the US [emoji848]
 
As Patrick (EUVL) has stated, Source and Drain of the 2SK209 are interchangeable. In the space allotted for the SOIC devices you can fit two of the 2SK209 or LSK170A. Note that two of the pads of the SOIC devices are are unconnected so you can jury-rig a connection. Sorry for the poor resolution:
 

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Ordered six of the Linear LSK389A SOIC JFETs from NAC to populate the two SOIC boards. I was able to get good matching within the six that I received. With the 10 ohm degeneration resistors the bias currents for the front end were 3.3 and 3.4 ma. Each JFET in the dual package measured within 0.1 ma.

The wattage on R9 ,the 499 ohm resistor is about 90 mW, good for 1/8 watt resistor.
 

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