AKG MI 201-100 microphone

Another great sounding microphone


Omnidirectional.


Some s problems. Later addition. Not sure if they come from the mic or the following amplifiers.


The microphone has 800Ω output impedance. Layer addition. It was measured to be 667Ω. After a few day it was measured again 830Ω. Possible aging electrolytic capacitor effects on the Escort LCR digital meter.


On the following setup, sound quality was greatly changed by connecting in either polarity. It seems to be an electrical effect than acoustic phase effect that needs to be explained. Late addition. Possibly just phase with respect to the phase of the monitoring headphones when monitoring in real time. A phase inverting adaptor solves the problem.


The Sotwer transformer used synergies very well as it goes very low in frequency and the microphone does not. So together they give a flat frequency responce from singer's vocal chords to listener's brain.


Setup, signal path:


(1-3inch) - (AKG MI 201 - 100) - Sowter 3104x (1:10), input inductance 3.9H - Pleiades V4 at 3.4volts - Realistic Disco Mixer mic mono input - HD580


Great sound when the mic is used very close, full body and detail. It sounds so natural like an acoustic transmission line.


The Beyer M55, at close distance vocals needs an input transformer of only about 400mH input inductance to sound correct to listener's brain as the 400mH introduces the desired low cut together with the mics 500Ω output impedance. (Later addition, more than 400mH, ie of the order of 1.7H may be needed. The transformer measured exhibits a much higher inductance at low frequencies due to the magnetic material used, see other posts.) It then sounds amazing.  No sibilant problem. Many commercial inline low to hi Z transformers already have this order of inductance. A Pleiades transformer can be made using relatively few turns with a Magnetec Nanoperm Nanocrystalinne tape wound ring core.


The AKG MI sounded fantastic on piano.


Just by being placed on top of an upright piano with its tiny plastic support stand.


Setup:


L channel - Beyer M55 -

                                             - Sony TCD5 Pro II - HD580

R channel - AKG MI 201-100 -


The piano was played softly.


So expression was captured and the sustain and clarity of high notes was a joy to listen to.


Later addition 18101218


It sounds very natural just connected to the amazing Uher 4200 report portable reel to reel. See a forward in time euroelectron post.


It sounds great directly connected to Sony TC-D5 Pro, the Sony used in real time as a mic amp and headphone drive amp.