Yes, loadlines... I'm more of a tweak and listen kind of guy, but indeed the time has come to learn to read them...
I'm building the 12b4 preamp schematic + ps as seen on diyparadise.com
Schematic:
http://www.diyparadise.com/12B4pre.html
Please note that Yeo (the guy from the site) uses a 12k anode resistor, and not 8.5k as indicated on the schematic
Power supply:
http://www.diyparadise.com/simplepreamp.html
(it's the one at the bottom of the page. Yeo uses it with both the pictured 5687 and the 12b4 preamp)
More info on the 12b4 pre can be found on the mentioned site.
Now we're at it...Maybe I could use a rectifier tube with less voltage drop (6x4 isn't too 'efficient'), e.g. GZ34? Should I look at the loadlines of the rectifier, or can one swap rectifier tubes without too much fuss - respecting offcourse the max. Voltage, ampere and capacity limits and realising B+ will change?
Something I couldn't get an answer to yet:
Is a power supply a carefully designed circuit that's married with the signal circuitry, or does one take some general rules into account and improvise? For example if you take Duncan amps ps simulator (which is above my head for now), it seems nearly impossible to get a good 'plot' (that rises fast to the high voltage) when inserting large capacities (e.g. 470µF). Why is it then that some people (who design kits so are expected to know their stuff) design a ps with a 470µ cap? Do they know how to make it work after long and meticulous designing, or don't they measure/simulate at all and just choose some capacity at random - and listen?
Why do some very experienced designers always put a smaller value cap (say 10µ) right after the rectifier, then followed by larger capacities. And why do other very experienced designers always put a smaller value cap always on the B+ side of the ps?
Life's mysteries
Thanks for your replies
