moving-coil preamp

7-98 elektor july/august 1980 Table 1. Type TIP 30A BFY 90 BFW 92 BF 181 BFW 16 A Table 2. b/K21 Manufacturer 13 Texas Instruments 21 Philips 16 Philips 12 Philips 4 Philips 20 50 100 200 500 1k 50 x preamp 2k 5k 10k I (H•) 80616 2 RIAA preamp. 102 moving-coil preamp Everyone knows that there are only two ways to connect moving-coil phono cartridges: either through a transformer or a pre-preamp that uses lots and lots of transistors. It is rather surprising, therefore, to find a design using only three transistors! 1 This circuit, by E.H. Nordholt and shown — player! not inside the record 10V 0 R.M. van Vierzen, appears in the April 1980 issue of the Journal of the Audio Engineering Society. The original article is extremely interesting, but also rather lengthy, so we will restrict ourselves to the conclusions. In the first place, it is shown that in a design of this type the internal base resistance of the transistor is highly important for the noise performance. The value of...