Understanding power supply filters in your amp

A sub forum for our most useful repair, maintenence & upgrade threads.
Post Reply
User avatar
Soochdaddy
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 2389
Joined: Wed May 30, 2007 9:47 pm
Location: SoCal

Re: Understanding power supply filters in your amp

Post by Soochdaddy » Thu Mar 10, 2011 12:20 am

øøøøøøø wrote: So basically, it's like we're turning a big "tone control" all the way down to filter out the unwanted signal, in this case 120Hz ripple voltage (and its harmonics).
Best. Analogy. Ever.
"I want to be able to purchase gin in bulk at Costco on a Sunday. So I totally voted." - chrisrnps

"Always socks on cocks-as to protect my low hanging guitar from getting 'cock rash' when playing in the nude, of course." - basique

User avatar
al30
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 564
Joined: Fri Mar 12, 2010 6:55 am

Re: Understanding power supply filters in your amp

Post by al30 » Thu Mar 10, 2011 6:32 am

Nice post

User avatar
i love sharin foo
Mods
Mods
Posts: 5127
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Understanding power supply filters in your amp

Post by i love sharin foo » Thu Mar 10, 2011 7:33 am

I've always wondered what exactly the filter caps did too. THanks a lot for the post. I am accumulating all the parts to build my first amp right now, so it's nice to gain a better understanding of what everything does before I get started.
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
OffYourFace
Mods
Mods
Posts: 12185
Joined: Thu May 03, 2007 2:59 pm
Location: Sherman Oaks, CA

Re: Understanding power supply filters in your amp

Post by OffYourFace » Thu Mar 10, 2011 11:17 am

dyn-o-mite!
synth tech at www.rosensound.com

User avatar
46346
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 2574
Joined: Sun Feb 27, 2011 1:39 am
Location: South Los
Contact:

Re: Understanding power supply filters in your amp

Post by 46346 » Wed Mar 16, 2011 12:29 pm

dude! can we get you a grant or something so you can teach us amp electronics over OSG? i'm digging this!
well written - thanks!
Dream Apes, ACME, Malcolm Mooney, Cat Museum, Cooling Time

User avatar
jorri
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1999
Joined: Thu May 07, 2009 1:53 am
Location: bath, UK
Contact:

Re: Understanding power supply filters in your amp

Post by jorri » Sun Jan 01, 2017 7:45 am

can anyone summarise what happens when caps leak electrolyte and old? I'm told they can start blowing fuses and become noisy, so is this just an intermittent short to ground and loss of capacitance?

Just replacing some big 4700uF caps and hoping that would resolve a fuse blowing problem. They are after the transformer, which might explain the huge difference in capacitance due to impedance, as well as only being 50V rated (although i then bought 100v anyway) as opposed to the usual 10-220uF 500V caps.

Playing around with values in my own pedal designs is pretty important. I do notice a certain undesirable tightness as high as 220uF and its not really making it darker in the same way as a signal path or emitter cap would.

User avatar
DeathJag
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 425
Joined: Wed Aug 08, 2018 11:44 am

Re: Understanding power supply filters in your amp

Post by DeathJag » Wed Feb 20, 2019 9:45 am

As someone who would eventually like to build amps -

Thanks a million, sir. That is awesome, just awesome. I’m gonna cut and paste the text for my “cheat sheet notes” to refer to in the future!

Post Reply