Friday, December 5, 2025

Second Pleiades RIAA MM Preamplifier Prototype

 

At your risk. A suitable fuse must be in series with any battery. Please take all other safety precautions.


Under preparation.

Instead of  one 9 volt battery this is supplied by batteries of total 18V or 24v.

Instead of 2 stages this has 3 stages but without source resistor bypass capacitor.

Even more similar to the Heathkit class A 10W integrated electron tube amplifier. 1st stage has a 100K drain resistor, second stage a 220K drain resistor. 3rd stage will possibly have a 10K drain resistor, said stage driving through a coupling capacitor a 10 to 1 output transformer.

A 1M potentiometer will drive the 3rd stage.

The passive RIAA filter, all 4 time constants, is at the time being between 1st and 2nd stage.


 

  

No comments:

Post a Comment