Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Return to Tube DIY Asylum


Message Sort: Post Order or Asylum Reverse Threaded

Why might someone do this for an audio circuit?

108.213.216.95

Posted on November 15, 2014 at 10:28:29
GSH



 

Hide full thread outline!
    ...
RE: Why might someone do this for an audio circuit?, posted on November 15, 2014 at 10:46:56
Triode_Kingdom
Audiophile

Posts: 10011
Location: Central Texas
Joined: September 24, 2006
The small parallel caps create a resonant circuit for greater attenuation of the ripple frequency. They also - unfortunately - create a path for high frequency noise to bypass the supply.

 

RE: Why might someone do this for an audio circuit?, posted on November 15, 2014 at 11:08:39
GSH
Could the high frequency noise be an attempted "fix" for a loss of highs due to other issues? For example: a high Rp low current driver attempting to drive a 2A3?

 

RE: Why might someone do this for an audio circuit?, posted on November 15, 2014 at 12:27:37
Chip647
Audiophile

Posts: 2633
Location: The South
Joined: December 24, 2012
Here is how to calculate the frequency of the tank circuit.

A 0.335 Henry choke and a 5uF cap gives a resonant frequency of 120hz, which is the frequency of a rectified 60hz line. You could trick it in to addressing the rectified line hum. Two 5uf caps in parallel will create a low pass filter as well, if the resistance to ground is greater than 2000 ohms this is OK, less than 30hz, but if the path to ground is less than 2000 ohms it will let frequencies around 60hz and above into the circuit unimpeded. There is also the noise leakage through the cap as well.

Yes, people use noise to make things sound more exciting.

 

"Yes, people use noise to make things sound more exciting.", posted on November 15, 2014 at 12:48:11
GSH
I was guessing that, thanks for explaining.

 

RE: Why might someone do this for an audio circuit?, posted on November 15, 2014 at 14:39:08
Tre'
Industry Professional

Posts: 17260
Location: So. Cal.
Joined: February 9, 2002
"Yes, people use noise to make things sound more exciting."

I have encountered people confusing high levels of upper ordered harmonic distortion as "speed" or "good transient response".

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

Page processed in 0.023 seconds.