16-11-2022, 07:08 PM
(This post was last modified: 16-11-2022, 07:12 PM by Murphyv310.)
Hi
Addendum. Strapping the G3 to ground isn't always a good idea so discount that train of thought. One thing I missed was the G2 directly connected to HT, not a good idea as ideally we want the G2 at a lower potential than the anode, so you need to feed it via a suitable resistor and decoupled. Also you'll need to add a resistor in the HT line between the output stage and before the ECC83 of about 2.2k decoupled with a 10uf, it may also be prudent to also do the same between the ECC83 & EF91. The amp has no NFB so the decoupling is even more important to reduce any possible instability.
Hope all this helps.
Addendum. Strapping the G3 to ground isn't always a good idea so discount that train of thought. One thing I missed was the G2 directly connected to HT, not a good idea as ideally we want the G2 at a lower potential than the anode, so you need to feed it via a suitable resistor and decoupled. Also you'll need to add a resistor in the HT line between the output stage and before the ECC83 of about 2.2k decoupled with a 10uf, it may also be prudent to also do the same between the ECC83 & EF91. The amp has no NFB so the decoupling is even more important to reduce any possible instability.
Hope all this helps.
