- LDCX2 - Modifying a BM800 microphone for use with a

34mm large diameter capsule

• Replace both the capsule and the circuit to improve overall performance

• Can be used with either a ‘side address’ or an ‘end address’ mounting saddle----( ‘Side address’ saddle from Tom Benedict here:

https://www.shapeways.com/product/AX4APE9SV/k87-saddle?optionId=65223254 )

( ‘End address’ saddle files here: https://www.thingiverse.com/thing:3085428 )

• Circuitry mounted on low cost stripboard to allow an easy application of alternative circuitry

• Schematic and detailed construction notes on pages below

© Jon Shaw 2018

Notes:• VR1 can be adjusted to vary the gate bias on Q1 to minimise distortion. Figures around 0.03% with an input of -10dB are typical.• C2 and C3 can be varied to limit the extreme LF response if required. A value of 100nF will give a rolloff of around -3dB at 40Hz.• R4, R5 and C7 can be selected to vary the high frequency response. The values shown will give a roll off of around -3dB at 8KHz. This can be useful when used with K67 type Chinese capsules, which can often be overly ‘bright’..