Product Overview
8-pin DIP precision operational amplifier, commonly used in the RAT or Rodent distortion circuit
These have become the stuff of myth and legends. We do our best to find, test and offer genuine chips. We do test chips ourselves and also ask a few trusted customers to try them out from time to time in their own distortion circuits. The two tests we do internally are :
1) Do they sound right in a distortion circuit?
2) What's the impedance between pins 1-5? (The datasheet says that impedance should be zero. However many chips labelled LM308N measure 2.4K-2.8Kohm impedance and sound genuine in the circuit.)
We can no longer say with any certainty what a 'genuine' LM308N is, and will not guarantee it unless we have written documentation (provenance) for a particular batch.
What we CAN say is that these ICs are tested using the two tests we noted above. We consider them 'real' LM308N for purposes of this listing and your circuits.
SKU ICTHLM308ND: Motorola logo - This batch is from a trusted supplier. These chips measure zero impedance between pins 2-5 and sound genuine in our test circuit. Date code is K8505A. The 'ND' suffix is unusual.
SKU ICTHLM308NJM36RB: Natl Semi logo- From another trusted supplier. These test well in the test circuit and measure impedance at 2.4kohm to 2.8kohm between pins 2-5.
SKU ICTHLM308NJM21RB: Natl Semi logo- Part of Small BEar acquired NOS. These test well in the test circuit and measure impedance at 2.4kohm to 2.8kohm between pins 2-5.
Also note: OP07AD is widely recognized as a reasonable sub for LM308N in these circuits.
Some builders elect to use LM308AN in the CAN package in place of the DIP version.