kambo

tube power supply choke...
« on: December 28, 2009, 11:29:10 PM »
is there any real need/benefit for choke on B+ tube PSU
 
ie: slow blow mic pre PSU...



CJ

Re: tube power supply choke...
« Reply #1 on: December 29, 2009, 12:29:42 AM »
you really do not need a choke for a mic pre,

the more power the amp handles, the more you need a choke, to regulate the pwr supply mostly,

so if you have a big stereo amp, you do not want the pwr supply to sag with a heavy bass note,

so a choke smooths out the current feeding the amp.

with a mic pre, you really do not have these large surges of current needed to run the thing,

so a simple resistor is ok,  you might need larger value caps with the resistor pi filter, no biggy

i have A/B ed a choke vs a resistor in a mic pre and heard no difference in hum reduction or sound.


the trouble you have with a cheap pwr supply in a power amp is all the current goes thru

a pwr resistor, so this creates a voltage drop across the resistor, which gets heard in the music,

the choke has a little dcr from the copper winding, but nothing compared to a dropping resistor.
« Last Edit: December 29, 2009, 12:33:33 AM by CJ »
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

kambo

Re: tube power supply choke...
« Reply #2 on: December 29, 2009, 12:56:52 AM »
thank you CJ. makes perfect sense. i was little confused after reading a lot about chokes.

kam


CJ

Re: tube power supply choke...
« Reply #3 on: December 29, 2009, 01:02:42 AM »
well, you might be getting confused with the parafeed thread in the Drawing Board?

i guess you could think of that as a pwr supply shoke, it just shoots upward off the B + line instead of

horizontal, but we analyze that circuit a bit differently than the straight pwr supply for a mic pre.

it is considered more part of the actual amplifier circuit than a simple pi filter choke,

mostly because of the difference in sound it offers
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

kambo

Re: tube power supply choke...
« Reply #4 on: December 29, 2009, 01:09:57 AM »
and also some many pages from Googled articles . they were mostly power amp PSUs based tho...


 

Related Topics

  Subject / Started by Replies Last post
1 Replies
1758 Views
Last post February 17, 2005, 03:16:06 AM
by gyraf
2 Replies
1641 Views
Last post December 04, 2006, 03:29:22 PM
by ohhey
1 Replies
2363 Views
Last post November 13, 2007, 06:27:22 PM
by CJ
2 Replies
721 Views
Last post July 20, 2018, 05:01:50 PM
by pedjoh18