JBL 5306 and 5308 mods:

Link to 5306 Mods: http://beyondsanityproductions.com/index.php?option=com_content&task=view&id=34&Itemid=28
This is the place where I got my info. Check it out and his other mods. Great stuff!!!
Note: this is a older piece of music gear and might need a re-cap. _______________________________________________________________________________________________________________________________________________
Channel Direct out MoD:
- I used switched jacks on the outputs, so if I didn't have a output cable plugged in, that channel would go to the mix buss.
- unsolder the 51k resistor that connects to the gain pot for each channel. Leave it soldered to the mix buss strip. Use a 2 conductor + shield cable (microphone cable works).
- Connect one wire to the pot where the resistor was connected. This will be your output.
- Connect the other wire to the unsoldered end of the resistor. This will be your return.
- Solder the output wire to the tip of your switched jack and the return wire to the switched contact.
- Connect one end of the shield wire to ground. leave the other end un-connected.

- I can put in -20db pads, phase inverse, and phantom on each channel. Like jensen's standard microphone preamp. www.jensen-transformers.com/as/as016.pdf

+48v phantom MoD: - I put a 48v phantom power board in there, tapped off the main PSU cap. Use matched 6.81k's to pins 2,3 of xlr.
PCB file

Capacitor MoD (Line and Headphone amp): - Bypass c411, c419, and c420 with .047uf film caps.
- Bypass c418 and c424 with 1u film caps.

Here are some images:
           Schematic PDF

Disclaimer: I encourage people to DIY and I'm here in a informative role.


ModDefecation is about making equipment sound better, providing knowledge and support, repairing that awesome piece of gear, and custom builds. Send me you questions or Ideas.