I have been modifying an old Carvin mixer. I will give details for my mods hen explain my new ideas and hopefully you guys can walk me through getting things where I want.
First : I replaced all TL075 op amps in preamp/EQ with Brown dog adapters and Burr Brown OPA2604 op amps. This made a huge difference in sound. One that I liked and the Preamps seemed to come alive. I added Wima 0.1uf caps to each power supply feed to decouple my issues I would have with power supply issues.
Second : I replaced all LM4136 op amps in the entire circuit with the TL075s that I pulled from the board to make room for the OPA2604s. I have read that the TL075 is superior to the 4136 and not only sounds better but operates better too?
Third : I replaced the NE5532's in the circuit with OPA2134s and replaced the lone 1458 with a NE5532. Again, decoupling caps were added to all power supply feeds on each op amp.
The Carvin mixer had four graphic EQs loaded with TL075's and 4136's. I cut them out of circuit and removed them. I plan to use the power supply from those EQs to power four additional Preamps.
I plan to use a Transistor balanced mic input using BC550's and 2N4403's, an Analog Design OP275 preamp Stage and a Edcor PC Series balanced output stage. Could someone help me with PCB design for the preamp? I am willing to pay and any help would be greatful.
First : I replaced all TL075 op amps in preamp/EQ with Brown dog adapters and Burr Brown OPA2604 op amps. This made a huge difference in sound. One that I liked and the Preamps seemed to come alive. I added Wima 0.1uf caps to each power supply feed to decouple my issues I would have with power supply issues.
Second : I replaced all LM4136 op amps in the entire circuit with the TL075s that I pulled from the board to make room for the OPA2604s. I have read that the TL075 is superior to the 4136 and not only sounds better but operates better too?
Third : I replaced the NE5532's in the circuit with OPA2134s and replaced the lone 1458 with a NE5532. Again, decoupling caps were added to all power supply feeds on each op amp.
The Carvin mixer had four graphic EQs loaded with TL075's and 4136's. I cut them out of circuit and removed them. I plan to use the power supply from those EQs to power four additional Preamps.
I plan to use a Transistor balanced mic input using BC550's and 2N4403's, an Analog Design OP275 preamp Stage and a Edcor PC Series balanced output stage. Could someone help me with PCB design for the preamp? I am willing to pay and any help would be greatful.
