Alternative Voltage for the "Bo Hansen Direct Box."

[Saransk93]

While the design was designed for 48 volt phantom power (then changed to 24 volts), I wonder if it could be redesigned to use 18 volts which is a common voltage on most pedalboard power blocks.
I as because several of the venues I play guitar in do not have 48 volt phantom power.
I know the DI was designed for the best headroom vs noise, etc., but since it will be used for guitar, I think the overall frequency response and such could be lowered without too much loss of sound quality.
I do use an external PS but it kind of defeats the purpose of a small DI for my guitars.
Thank you
Michael

 

[tk@halmi]

https://www.hansenaudio.se/Active DI-box 1975, new schematic.png

You could try feeding it with 18V to the right hand side of the LED instead of the 6.8K resistors. t is just two emitter followers back to back and really not all that fussy.

if you want to do it right when changing the operating point of a circuit you do a few measurements. Best would be checking headroom and clipping points with an oscilloscope.

 

[TimG]

Post in thread 'UTM INDUSTRY audio transformers - from Poland - EU'
https://groupdiy.com/threads/utm-industry-audio-transformers-from-poland-eu.79307/post-1141343

I still need to finish this but it runs off 16v 500 rack power.