Some time ago I’ve received a Technics SL-1910 turntable from a friend. At that time mine problem was that this turntable doesn’t have integrated RIAA network and my vacuum tube stereo doesn’t have too. I needed an external RIAA active network to equalize the audio from the turntable and rise it’s volume to the 1,5Vpp needed to drive the stereo amplifier. I’ve designed a simple active RIAA network powered by a low noise op-amp NE5534 or OP27 or other pin-to-pin compatible op-amp’s. I’ve made some PCB’s for it too. I sell the PCB at 5€/each plus shipping. Contact me for more info or buy.
The simulated circuit result and the result from the real circuit measure fits very well.
All resistors are 1/4W
- All capacitors must be high-quality poliestere but I’ve used standard ceramic type without any issue
- IC’s are mounted on DIP-8 package
- I/O are made soldering directly coax cable from RCA sockets to the pcb
- The circuit is powered by 2x 9V battery to minimize noise from power supply. I use a connection like this to power the circuit. Just add a double trow switch to connect/disconnect the +9V and -9V supplies.
- The output cap must be a 2.2uF polyestere non polarized from WIMA or high-quality equivalent.
- The PCB that I’ve realized is 100x50mm in size, 1.6mm FR4 thick, double layer professionaly made. There are 4 mounting hole at corners. The PCB is noise free without any enclosure thanks to my design but I sugest you to enclose it into an alluminium enclosure like this one, cheap, from banggood.com
- For I/O use only quality gold plated RCA connectors mounted on the alluminium front/real panels
Riaa_1 click here to read the BOM (bill of materials)