Sorry - I am rather late to the party with these regulators - I bought some a long time ago and only now have I got around to building a homebrew HiCap for my Naim NAC 72 pre-amp. Regaulators are working OK and i'm just dotting the i's and crossing the t's before installing everything into a case.
In the build documentation the BOM says not to fit C5 & C7 but the remaining documentation mentions their function and the circuit diagram clearly shows them. Does anyone have any thoughts on whether to add them or not? C5 is 100uf and decouples the emitter of the pass transistor to ground. The NAC 72 has a number of "daughter cards" each with 47uf decoupling capacitors. Should I eliminate C5 and keep the NAC 72 decoupling capacitors as-is or go with my gut feeling and install C5 and reduce the local decoupling in the NAC 72 to say 4.7uf film caps?
In the build documentation the BOM says not to fit C5 & C7 but the remaining documentation mentions their function and the circuit diagram clearly shows them. Does anyone have any thoughts on whether to add them or not? C5 is 100uf and decouples the emitter of the pass transistor to ground. The NAC 72 has a number of "daughter cards" each with 47uf decoupling capacitors. Should I eliminate C5 and keep the NAC 72 decoupling capacitors as-is or go with my gut feeling and install C5 and reduce the local decoupling in the NAC 72 to say 4.7uf film caps?
Fit both.
C7 is essential, since it reduces AC frequency response to unity-gain; that makes the reg quieter and better-performing.
C5 isn't essential- but with it you know the reg will be stable. Keep the 47uF decoupling caps in position on the NAC boards, if that is what you are using these regs for.
Do.not idly swap the 47uF decoupling caps on the reg boards for 4.7uF film - that is a good way to make such a high-performance regulator oscillate at HF.
The existing 47uF have a bit of ESR - and that is actually useful, when implementing 'fast' / high-bandwidth regulators, since it adds damping.
C7 is essential, since it reduces AC frequency response to unity-gain; that makes the reg quieter and better-performing.
C5 isn't essential- but with it you know the reg will be stable. Keep the 47uF decoupling caps in position on the NAC boards, if that is what you are using these regs for.
Do.not idly swap the 47uF decoupling caps on the reg boards for 4.7uF film - that is a good way to make such a high-performance regulator oscillate at HF.
The existing 47uF have a bit of ESR - and that is actually useful, when implementing 'fast' / high-bandwidth regulators, since it adds damping.