MD21 HL or SM200 connected to iPad

At your own risk.


The microphones tested were the Sennheiser MD21 HL and the Schaub Lorenz SM-200.


The combination is very nice. World class sound. Extremely low noise. One can sing softly on the Sennhesier MD21 HL and the rec level sensitivity on iPad being just at half way for full VU meter modulation. At 1 inch the sound is amazing at any recoding  untreated space.


The iPad GarageBand has a low cut at around 300Hz which compensates for the increased brain perceived bass when using the MD21. So there is synergy between the two.


The Schaub Lorenz sounded nice too, less low noise.  One can adjust the bass responce by moving close or further to the mic, finding the sweet spot by exploiting the proximity effect. It is nice that this microphone does not go very high in frequency compensating for increased HF brain perception due to voice effort and Fletcher Munson curves.


The Sony F-96 Hi Z is a good candidate too as it is bass heavy for voice on its own, and this will be compensated by the iPad Gargeband combination. This mic too may possibly not be as high output and low noise as the MD21 but good results should be possible by using the microphone at close distance.


Both mics have an internal stepup transformer which is very convenient. Then a Pleiades K117 JFET preamplifier housed inside the mini Tuchel connector is driven. This preamp is then powered by the iPad headphone mic connection. Similarly to connecting or powering the internal amplifier of electret condenser microphones.


More information or schematic on previous euroelectron posts. It is portable, just the MD21, the iPad and the headphones. World class sound.


Setup, signal path:


Almost any acoustics - Sennheiser MD21 HL - Pleiades K117 with 220Ω drain resistor, Hi Z from the transformer mic out connected to gate, iPad mic connector pin connected to drain - iPad GarageBand - Sennheiser HD 580


Caution: A gate resistor may be needed to avoid possible gate static voltage buildup and possible blowing of the microphone transformer secondary.