Hi all, searched and couldn't find an answer on this one. Given the same OPT and tube, in this case a Hammond 1628se and an EL84, how does input grid capacitance vary between triode, ultralinear and pentode connections? I know triode is higher than pentode but can't find an answer to where ultralinear falls.
The question comes from playing around with a direct coupled EF86-EL84 SE. Converting the output stage from pentode to ultralinear appears to have ameliorated the funkiness of the Hammond around 13 kHz but also results in an impressive rolloff at 15 kHz. I'm trying to figure out if the latter is a result of reduced gain available for global feedback or the EF86 choking on the new load. Thx in advance.
The question comes from playing around with a direct coupled EF86-EL84 SE. Converting the output stage from pentode to ultralinear appears to have ameliorated the funkiness of the Hammond around 13 kHz but also results in an impressive rolloff at 15 kHz. I'm trying to figure out if the latter is a result of reduced gain available for global feedback or the EF86 choking on the new load. Thx in advance.