right so to deisgn a power supply i need to know the voltage desired and the current that will be drawn,
but from the curves for the kt88 (my output tube of choice for my amp) i have noticed that when in triode mode (as i want a switch to allow mode changing) the kt88 idles at 60mA as opsoed to ultralinear mode at 80mA.
but from the curves for the kt88 (my output tube of choice for my amp) i have noticed that when in triode mode (as i want a switch to allow mode changing) the kt88 idles at 60mA as opsoed to ultralinear mode at 80mA.
i did i simulation of an idea in duncun psu designer and when i go from 120ma draw (both tubes in triode mode) to 160ma draw (both tubes in UL) i get a voltage drop of about 15V,,,
is there anything i can do about this?
oh and i wouldn't ever hot switch anyway to many expensive components to potentialy damage..
is there anything i can do about this?
oh and i wouldn't ever hot switch anyway to many expensive components to potentialy damage..
About the only thing you can do to reduce or eliminate it is build a beefier supply with less losses, or active regulation.
A somewhat higher anode voltage in triode mode isnt a disaster (assuming it doesnt take parts past ratings), check for the current it will draw at this different operating point.
Alternate bias for triode mode is another possibility.
A somewhat higher anode voltage in triode mode isnt a disaster (assuming it doesnt take parts past ratings), check for the current it will draw at this different operating point.
Alternate bias for triode mode is another possibility.
try 300 ohm as the transformer resistance, if you get a transformer that has al lower resistance, i recomend resistors before the rectifier(better dampening factor). First cap 8uF, replace the 330uf cap with a good 100uf cap. Then replace the 33uf cap with a 20uf cap.
Now you have a faster psu with slightly more ripple with a better dampening factor and without the current spike.
But personally, I would have complete redesign of psu instead.
siang
Now you have a faster psu with slightly more ripple with a better dampening factor and without the current spike.
But personally, I would have complete redesign of psu instead.
siang
Choke input example with 50hz Hammond parts.
Hammond 372FX PT -- 5V3/UF4007 hybrid bridge rectifier* -- Hammond 193J 10H choke -- large filter capacitor. Add RC section if ripple too high. I get about a half volt p-p as is.
Use measured values for sim data entry if possible.
*5AR4 GRAETZ may model in PSUDII.
Hammond 372FX PT -- 5V3/UF4007 hybrid bridge rectifier* -- Hammond 193J 10H choke -- large filter capacitor. Add RC section if ripple too high. I get about a half volt p-p as is.
Use measured values for sim data entry if possible.
*5AR4 GRAETZ may model in PSUDII.
If the screen and grid voltages don't change, then the current won't change. The screen voltage won't change by more than a couple of volts when switching between UL and triode, so both modes should draw very nearly the same idle current from the supply.
Anyway, if you want a good regulation then I suggest you build a good choke input supply and enjoy the music. By good, I mean that you use transformers and chokes that are decent quality and and rated for more current than you'll be asking of them. You can always experiment once the amp is playing music.
Anyway, if you want a good regulation then I suggest you build a good choke input supply and enjoy the music. By good, I mean that you use transformers and chokes that are decent quality and and rated for more current than you'll be asking of them. You can always experiment once the amp is playing music.
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