6.6 amps for the EL3N? Wow! If I remember correctly, an OTL with the original transformer has a rectifier winding rated at 5.0 amps. And even this is likely enough for any rectifier. At the least, none of my rectifiers, 3.3V, 4V and 5V, totaling about 50 in all, draw more than 4.0 amps.