El34 has a long tenured history, known for its pronounced distortion characteristics, distinct over other power tubes such as 6550. many oem amp makers utilized el34, especially early/late marshall, to often achieve a heavy rock ambience and/or softer sound marantz, dynaco mark 2/4 +stereo-70, leak st-50/60, scott, hiwatt, orange, laney, heath, traynor, eico, fisher, pye mozart + more.
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