Fortifying +48V Phantom Power

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

benlindell

Well-known member
Joined
Feb 28, 2009
Messages
631
Location
NYC
This is a general question that I had.

I have a 4 channel preamp with JLM Go Betweens with FET DI for each channel. using the SSL9K PSU I can't get the +48V rail to keep up enough power, unconnected I get 48.6V, with the 4 Go Betweens I get +28.5V. I'm assuming this is from the relays and other components on the DI that are drawing too much power. Can I make a simple capacitor bank to fix this up/make more power available to draw?
 
increasing C3 and C4 from 100uF to 1000uF and C5 from 220uF to 470uF should do the trick for the max.draw of 35mA/FET DI.
From yur measurements you already seem to have decreased R2 from 240R to 220R to come closer to 48V, but depending on transformer secondary ACV have an eye on ripple and regulators dropout voltage. With this amount of current draw, better put a heatsink on IC3.
 
Back
Top