Dip Switch positions explained
If not using the DPDT On/On switch (seen next page) you may use a pair of
●
To activate the AfterBlaster both Number 1 Switches should be in the
ON
position, and both Number 2 switches should be in
the
OFF
(or facing Number 2) position.
●
To bypass the AfterBlaster both Number 1 switches should be in the
OFF
(or facing the Number 1) position and the Number
2 switches should be in the
ON
position leaving you with the stock circuit.
●
The Dip switches will not be functional in any other configuration. Either set both on 1 or both on 2.
SCHEMATIC
Additional Build Notes:
While 2.4k will give you desirable results, if you wish to
fine tune
the Bias resistor use a socket on R4 then measure the Drain voltage
of Q1 and adjust the resistor to achieve the exact results you like. Remember every MPF102 is going to be different so 2.4k is a
working approximation. The preferred voltage range for the Drain of Q1 to ground is between 4.5V and 5.0V. Once you find the
perfect resistance you can solder it to your socket. (Again this is an optional procedure)
It is very convenient to use (4) connected socket sections and either push out the two middle pins or clip off the middle pins with
wire cutters to easily solder a solid section to the board when only needing (2) sockets.
If you are having trouble determining which Dip Switch setting is After Blast and which is Bypass, just turn your Trimmer and you will
hear it clearly when you have it in After Blast Position. Typical Unity setting is at about 1:00. Below that you are attenuating the
circuit (which can be useful, while maintaining natural Bass loss) and anything above 1:00 will add enhancement to finally a clean
Boost.
