> I did simulation using the SPICE models of your D3a and
> Orange Color LED of LNJ812R. The schematic is shown in the
> attached photo. My simulator cannot calculate KOREN's 6SN7
> due to "Missing of OpeLand". Right side of the schematic
> shows Ayumi's 6SN7 model. The results are indicated in the
> photo. THD=0.95% @20.62Vrms Output is not so bad figure.
Thanks for checking, could you please post the Koren model so I can try and find out why it does not run. As for the result of 0.95%, it is still quite high, as the THD is only around 0.3% (-50dB) in the actual circuit. Please also take a look at Ayumi's 6SN7 model in the positive grid region compared to the GE datasheet, the curves do not match up well. Very strange, since usually Ayumi's models are spot-on.