Toshiba 2SK147BL ultra low noise N-Ch J-FET and 43 similar items

Here is an Idss matched pair of extremely rare Toshiba 2SK147BL. It has been out of production since 1980's. It was designed specifically for audio use, in particular for MC and phono application, due to their ultra low noise and high gain. A comparison diagram of 2SK147 against the well-known 2SK170 depicts how well 2SK147 performs in terms of noise and high operating current. The JFET was so good that it can also be found in certain preamplifiers designed by John Carl. It is very difficult to match high gain JFETs such as 2SK147 due to the drift of Idss with temperature during sorting. Therefore we can only guarantee a variance of +/-0.2mA. This is more than enough if the JFET is designed to work at drain current of over 4mA. It is not a drop-in substitute for 2SK170 as the operating current is much higher , firstly to compensate for the higher input capacitor, and secondly, because of the almost doubled transconductance. With proper operating point, it can deliver a low noise and transparent preamplifier input stage hard to be exceeded by other JFET counterparts. This listing is for one pair. We do air shipping worldwide at US$6.00. We welcome combine shipping.