Power Filtering.

[leadfootdriver]

What's the general rule with power supply filtering? For example, what would the difference be if I used a 40 or 50uf cap for a pair of triodes instead of a 22uf?

[Colossal]

What's the general rule with power supply filtering? For example, what would the difference be if I used a 40 or 50uf cap for a pair of triodes instead of a 22uf?

For the pair of triodes, are you referring to their duties as preamp or power amp tubes?

In general, the larger the cap, the "stiffer" the feel. This is generalizing grossly because it does not take dropping resistors or chokes into account. Caps and resistors form "RC" networks and the amount of capacitance and resistance required is related to how low (Hz) you want to filter to. Chokes and caps form LC networks with filtering/ripple reduction properties as well.

Check out Valve Wizard's site for a good primer:
http://www.freewebs.com/valvewizard1/smoothing.html

[leadfootdriver]

What's the general rule with power supply filtering? For example, what would the difference be if I used a 40 or 50uf cap for a pair of triodes instead of a 22uf?

For the pair of triodes, are you referring to their duties as preamp or power amp tubes?

In general, the larger the cap, the "stiffer" the feel. This is generalizing grossly because it does not take dropping resistors or chokes into account. Caps and resistors form "RC" networks and the amount of capacitance and resistance required is related to how low (Hz) you want to filter to. Chokes and caps form LC networks with filtering/ripple reduction properties as well.

Check out Valve Wizard's site for a good primer:
http://www.freewebs.com/valvewizard1/smoothing.html

I guess there's a lot more to it! I ordered the Wizards power supply book a few days ago, but I won't get it until after x-mas. Amazon is slow right now!

I should probably just wait 'till I get read the book before I ask loaded questions!

Thanks.

[Roe]

for preamp 22uf is usually sufficient

[rdjones]

The only real "rule" I'm aware of is when there is a tube rectifier, the first cap in a capacitor input supply should not exceed the rating for that tube.
These values are lower (and more important) for directly heated cathodes, example 5Y3 is shown with a maximum 20u input cap.
The filtering downstream can be much higher but there's litter to be gained beyond 10x that which smooths for the lowest frequency to be reproduced.

rd

[leadfootdriver]

Looking at the Express schem, there's 2-40uf's after the rec. Doesn't the tube rec see 80uf?

https://tubeamparchive.com/files/tw_exp ... 08_334.pdf

[Colossal]

Looking at the Express schem, there's 2-40uf's after the rec. Doesn't the tube rec see 80uf?

https://tubeamparchive.com/files/tw_exp ... 08_334.pdf

Yep.

[cbass]

Looking at the Express schem, there's 2-40uf's after the rec. Doesn't the tube rec see 80uf?

https://tubeamparchive.com/files/tw_exp ... 08_334.pdf

The express don't havt a tube recto.The rocket does though.

[Colossal]

Looking at the Express schem, there's 2-40uf's after the rec. Doesn't the tube rec see 80uf?

https://tubeamparchive.com/files/tw_exp ... 08_334.pdf

The express don't havt a tube recto.The rocket does though.

Leadfoot's been considering his options about a switchable tube/ss rectifier for his build:
https://tubeamparchive.com/viewtopic.ph ... sc&start=0

[rdjones]

Power filtering is generally use for Aquarium. Most freshwater tropical fish keepers own aquariums ...

SPAMBOT !

[David Root]

Looks like it. How do we get rid of it and prevent others?

[Colossal]

The same spambot hit another thread too.

[RANT]I wish hackers, identity thieves, and spammers could be 'upgraded' by the State Dept. to terrorists because of all the economic and personal damage they cause. Maybe the idea of having a SEAL team come through your door and the last thing you see is the glare of a laser in your eye before they empty a magazine of plus-P 10mm into your head would be an incentive to curb at least some of it globally. I know most of it comes from other countries, out of the reach of SEAL teams (at least for now). I can dream though...[/RANT]

[ToneMerc]

The same spambot hit another thread too.

[RANT]I wish hackers, identity thieves, and spammers could be 'upgraded' by the State Dept. to terrorists because of all the economic and personal damage they cause. Maybe the idea of having a SEAL team come through your door and the last thing you see is the glare of a laser in your eye before they empty a magazine of plus-P 10mm into your head would be an incentive to curb at least some of it globally. I know most of it comes from other countries, out of the reach of SEAL teams (at least for now). I can dream though...[/RANT]

Sounds like terminal aberrant behavior correction

TM

[Colossal]

Sounds like terminal aberrant behavior correction

Haha, thank you for indulging me TM! I hate to sound like that, but yes, that is the idea. The world has become far too small for people that take so much from hard working people. Same with the mexican cartels. One simple solution: SEAL Team.

[ToneMerc]

Sounds like terminal aberrant behavior correction

Haha, thank you for indulging me TM! I hate to sound like that, but yes, that is the idea. The world has become far too small for people that take so much from hard working people. Same with the mexican cartels. One simple solution: SEAL Team.

Tier 1 gets the job done, much respect for SAS units as well.

TM