Topic: Bypass capacitors in the power supply

[ATJr.]

Here we go again...

seryosong question ito..

Why is it that on some components, I see copper screws (i am assumung its copper based on color) on sensitive areas, like FM boards etc ?

Hindi copper screws yan, but copper plated, my neighbourhood metal plating shop can do copper plating on screws or even metal chassis...

Sansui and others also used copper plating......

yan yung fad sa Japan in the 80's......just like circuits and devices, you will notice that for a certain time era, you will find similar circuits and devices across the industry......in time semicon devices become obsolete as new devices are invented.......and new fad cycles evolves.......

as to the sound, i leave it up to you, i have no other idea aside from the fact that copper is a better conductor than iron and steel....

[shrek7]

Innocent until proven guilty 

Ayoko na mag tanong, may isa pa akong tanong kasi I will keep it na lang for myself ..

hehehe! Joke lang brader, itanong mo na, at least ngayon experience naman ang usapan. Hehehe!

[ATJr.]

Thats correct, No bypass caps on the mail filter caps, Did not notice any bleeder resistors...I guess because I was not looking for it..

one more thing, if you count 2 relays in your amp, one of those will be for the soft start circuit...also on the power supply board...

[vhinx]

Master, I would like to ask if the by-pass caps will cause humming sounds too?

[ATJr.]

Master, I would like to ask if the by-pass caps will cause humming sounds too?

if the bypass has very high ESR it is possible, but there are other factors to humming, interconnects is one....

[qguy]

How can an interconnect cause humming ? Shorted ?

if the bypass has very high ESR it is possible, but there are other factors to humming, interconnects is one....

[ATJr.]

How can an interconnect cause humming ? Shorted ?

poor contact with the RCA jacks...making good contact is important.....

in one tube amp we were testing, there was a little bit of noise, not so pronounced but was annoying, later found out that the banana plug was a little loose, so after a bit of prying on the pin leaves and making a tight contact with the speaker jacks, the sound improved all of a sudden.......i was about to replace the opt's......

so when one member here posted in a thread about changing the speaker wires the sound improved, this could well have been the reason....not the speaker cable...the contact with the jack......

[vhinx]

How can an interconnect cause humming ? Shorted ?

Possible loosed loop grounding...

[vhinx]

if the bypass has very high ESR it is possible, but there are other factors to humming, interconnects is one....

The one I used was generic 0.1uf ceramic caps... I put it at my other Subsonic filter circuit to subwoofer.

[ATJr.]

The one I used was generic 0.1uf ceramic caps... I put it at my other Subsonic filter circuit to subwoofer.

ceramics are very good at filering emi/rfi and is best used directly in ic power pins....now if leads from the psu to the filter pcb are long(more than 6inches), then ecaps can be used as additional bypass....

[vhinx]

ceramics are very good at filering emi/rfi and is best used directly in ic power pins....now if leads from the psu to the filter pcb are long(more than 6inches), then ecaps can be used as additional bypass....

Thanks Ninong... I check my dirty circuit work again and apply your recommendation.

BTW, One more thing that Do I need put bleeder resistor even my power supply is 12-15vdc...?
Or it is Ok to use individual 12V LED to my rail to rail 12vdc power supply to drain the extra volts at main caps...?

[ATJr.]

bleeders are good, even at low voltages...

[sound garden]

[ATJr.]

just posted this over at diyaudio....http://www.diyaudio.com/forums/tubes-valves/219898-supermalloy-power-transformer.html#post3170397

sorry to dissapoint you but i am not one of those with golden ears.....to me it is not the ears, but the brain....there is where everything happens, in your brain.....the ear is just a port that converts sounds into electrical signals to be the processed by the brain... ..

[vhinx]

Medical term na eto Ninong and still going deep explanation...

[sound garden]

[qguy]

Mga Experts pa confirn naman....

I got this one, Is this type of capacitor safe/ok  to use ?  I understand this should be 2.2 at 250v ? Is this correct ?



I could install it like this, correct ?
and yes, I will insulate the exposed lead wire with scotch tape  .
There were other areas that was  suggested to install these caps, right now   I am not in a position to locate those areas as I may pick the wrong one and my amp may go puff.



and do the same for the other 22000 cap

Thanks

[ATJr.]

yes, 200v 2.2ufd cap.....

if you are installing bypass on the filter cap, and then that filer cap will have long leads going to the power amp board, then it is possible that high frequency resonances can result of connections formed by that cap and the leads..........ymmv...

[qguy]

Ok thanks..

yes, 200v 2.2ufd cap.....

if you are installing bypass on the filter cap, and then that filer cap will have long leads going to the power amp board, then it is possible that high frequency resonances can result of connections formed by that cap and the leads..........ymmv...

[odyopayl]

Ok thanks..

There you go qguy go go go!

[ATJr.]

the bypass caps will do more good right at power amp boards....