Saturday, October 13, 2007
John Broskie's B+ feedforward shunt regulator
i've actually got this board done up before i shifted. that must have been 3 or 4 weeks ago. i was even comtemplating putting it into my 5687 preamp the day before NoiSing07 so that i can demo the preamp with the regulator.
good thing that i did not... it took many attempts before i got it to work. most of the time, i burnt resistors as i forgot where the ground of the board is cos it was sooo long and i did not mark the board with symbols.
i also killed quite a couple of 10M45S chips. it seems that even though it is sourcing 10mA, heatsinks are still required on the chips.
it seems that the regulator added a sense of scale and resolution to my soundstage. it is easy to pick out details... very resolving. also, the bass seems to have benefitted by being more controlled and detailed. not quite sure how to put it, but i would say that this is worth the effort.
perhaps other HV regulator designs would produce the same effect?
the circuit is based on Jon's feedforward shunt regulator.
parts are swapped below as mentioned:
1. first dropping resistor after B+ as 1k2 10W instead of 309R
2. second dropping resistor after B+ as 2k2 10W instead of 614R
3. B+ is 290V, between dropping resistors is 228V and 136V (L channel)/140V (R channel)