Parts recommendations & options
To obtain the blank Mini³ circuit board and some related parts, visit the
almost everything else from the vendors listed on the
The following is a list of recommendations and options. Please read through this carefully before you
order any parts.
Resistors
•
All except R5: miniature 1% metal film type
Lead spacing 0.200" (5mm)
o
Xicon
o
o
Vishay-Dale
o
Vishay-Dale
o
o
other similar
•
R5: miniature 1% or 5% metal film or carbon film type
Lead spacing 0.200" (5mm)
o
Xicon
o
Panasonic
o
o
other similar
Notes about all resistors
The Mini³ circuit board is designed for miniature through-hole axial-lead 1/8W or 1/4W
resistors with a body length no longer than 4mm (the recommended Xicon, Panasonic and
Multicomp resistors are 3.5mm or 3.2mm), and no wider than 1.9mm. Do not use oversized
resistors, in particular do not mount resistors vertically ("tombstone style"). The extra lead
length adds unwanted inductance which could affect the stability of the amplifier.
Notes about R3 and R4
The voltage gain of the amplifier is determined by the ratio of R4L and R3L (as well as R4R
and R3R). The default values of 1.5K
Ω
and 330
Ω
, respectively, results in a gain of 5, which is
a good for a wide array of low and high impedance headphones. The following table shows
optimized resistor values for several other voltage gain settings. Please do not use other
values than listed to maintain low output DC offset and ultrasonic stability.
