JBL UREI 7110 MODS
These are signetics chips, I would leave them in.
- You could change IC3 to: (LME49710NA, OPA134, OPA602, opa627, or LT1357) and install a gold plated ic socket.
- You could change IC1, 4, and 8 to: MC33079, LME49740NA, OPA404, or OPA4227 and install a gold plated ic socket.
- Bypass the modded IC's V+ and V- (pins 4 and 8) with a .1uf capacitor to ground
Capacitor optional MoD:
- Remove c10, c11 and c12 and put in a 10uf polypropelene capacitor to the outer legs of c10 and c11.
HP filter (sidechain) MoD:
- Replace c26 with a 5mm pin placement film cap. (.022=144Hz, .033u=96Hz, .068u=46Hz, .047u=67Hz, .039u=81Hz, .027u=117Hz, .01u=317Hz)
- Drill a .25" hole in the front plate and install a spst switch. Wire one switch contact to one leg of c26 position. Wire the other contact to a .22uf 50v bipolar cap. Wire the other leg of the bipolar cap to the other position of c26. This switch will give you a normal, and HP filter setting.
Output transformer MoD:
- Cut and remove r21 and JW40 from the board. They are located in the dotted outline for the transformer. Solder in a 600r:600r Jensen JT-14550 transformer.
Disclaimer: I encourage people to DIY and I'm here in a informative role.
Here are some images:
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.