Analog simulation of magnetic tape analog sound recording part 11

An inductor of 26mH was connected across the output of the Sony CD Walkman line out 370Ω impedance.


The 26mH Pleiades filter should give an 70μs premphasis.


Signal path setup:


Constant Craving - K.D. Lang CD track - Sony CD Walkman line out - 26mH inductor (Pleiades filter) - (Pleiades V4 powered by 4.8V) - line in of Realistic disco mixer - Sennheiser HD580


The sound was very loud with great treble of good quality reminding of some great tube amplifiers such as Luxman.


There was distortion.


The fact that it was loud is very promising. When using 2 cassette heads with their airgaps joined it was very low.


Using just the Pleiades filter the signal was so loud that the line in instead of mic in input had to be chosen on the Realistic disco mixer.


The most likely component being clipped with this setup is the Pleiades V4 prepreamp. The treble sounded very lively. HF clipping sounded like a live haircut scissor. There was some distortion too on the voice.


A next experiment may involve using smaller inductors to make premphasis curves of much lower time constant. For example stopping increasing treble at 10KHz or even 20KHz.


Another experiment may involve using 2 or 3 E,I only laminations (very small iron crossection). Then winding many turns to make an inductance of 26mH. Hopefully this will reveal the sound of magnetic clipping which is the desired outcome.


Doing the above experiments and then de emphasizing to get back to flat frequency responce. A resistor in series with a capacitor to ground could be used to integrate or high cut (low pass). A potentiometer, a Heathkit capacitor switch box and a test CD may aid a lot. Level can be measured on the Realistic VU meter or by connecting an external VTVM.