What I am trying to come up with is a way to boost the typical .5-1V modern ceramic cartridges to the typical 3 volt output level that the older crystal cartridges had.
I'm working on a '48 Decca 78 rpm phonograph that used such a 3 volt cartridge to drive the output tube directly. Not wanting to spend the money for a cartridge rebuild, I installed an Astatic 89T; which, has an output of 1V. Although the volume level is OK, it could still be better.
On ARF, someone posted a diagram of a simple one transistor preamp that obtaines it's B+ from the cathode of the output tube. Either I'm missing something; or, the diagram is wrong because it does not work.
If anyone has any other ideas, I'd love to hear them. And, I'm sure others would, as well. Since these high output crystal cartridges are generally NLA, it would be nice to come up with a circuit that would allow use of a modern cartridge and the player still have the level of volume it did with the old cartridge.
Here's a link to the diagram, and the Decca record player that I'm repairing.
http://www.antiqueradios.com/forums/...c.php?t=122237