A way to power a JFET through an output transformer

Your own risk.


A fuse should always be connected in series with a battery.


This is on quickly trying the Pleiades V6 schematic with a JFET.






The is to connect an output transformer primary instead of a load resistor. Less Vb is needed as there is no voltage drop as when using a load resistor. But the signal is developed as the transformer primary becomes an impedance for AC or signal.


Examples:


Powering an electret capsule instead of trough an external resistor (or the internal of iPad for example) by an output transformer. Vb is applied to one side of the primary p, the other side of the primary connected to JFET drain. The secondary is the balanced output. Nice and simple. No capacitor, no resistor, less noise?


Powering a Pleiades K117 amplifier by just a battery in series with a transformer. So if for example a Sennheiser MD21 HN is used at high Z we have the Pleiades V6 schematic with high input and output transformer.


The transformer could be a 1:1 ratio. Or even a step up ratio so that a Tascam Porta can be greatly driven at its mic input with low noise and high sensitivity. A variation is using a circuit closer to U47. This is done by using normally a load resistor, then capacitor coupling to the output transformer primary. An example of this, using a step up military transformer from 600Ω to 20KΩ driving the Tascam Porta 07, is the song Lonely with Me - Delivorias on YouTube channel renewable music. The glockenspiel at the solo end of the song was recorded this way. The capacitor was deliberately small to high pass the glockenspiel avoiding thumps etc. The glockenspiel is a toy one made by Angel.