Lundahl LL1627AM amorphous core output transformer

Some of our tube output transformers are now available with amorphous core. Listening tests, in particular for the PP versions where the core airgap is not as dominating as in SE applications, have reported a more transparent, wider bandwidth character than our silicon iron counterparts. For connection alternatives and general application information, please refer to data sheets for our regular (silicon-iron) output transformers. The obvious measurable difference between our silicon-iron cores and amorphous cores is that the saturation flux for the amorphous core is approximately 33% less than for the silicon-iron counterpart. This is caused partly by a lower saturating flux level, partly by a smaller fill-factor due to the thickness of the amorphous sheets. As a result, power bandwidth is reduced by about 50%. (This means that if the max output power for a standard LL1620/40mA is 25W at 30 Hz, corresponding max. power for LL1620AM/40mA is 13W.) This is probably not a problem in most Push-Pull applications, but should possibly be considered in Single End amplifiers.