What would adding a choke to the power supply do?

[Nathan]

Been reading about a Triad C-7x choke at the last PS cap in place of the resistor which is across the cap. I've already bypassed that last PS cap with a Mundorf film cap.

Succinctly, what would the purpose and benefit of a choke at that location be?

Thanks in advance-

 

[borism]

Hi Nathan,
The choke replaces the 270 ohm 5w cement resistor (it's white and hidden from view) and not the 270 ohm 1w across the cap. I just put it in this weekend and followed this thread:
http://bottlehead.com/smf/index.php?topic=6030.0
Others need to explain the electrical benefits but sonically it is very audible and in my opinion worthwhile.

 

[Nathan]

Hi Nathan,
The choke replaces the 270 ohm 5w cement resistor (it's white and hidden from view) and not the 270 ohm 1w across the cap. I just put it in this weekend and followed this thread:
http://bottlehead.com/smf/index.php?topic=6030.0
Others need to explain the electrical benefits but sonically it is very audible and in my opinion worthwhile.

Thank you! I think the biggest issue is mounting the choke- I already have three bypass caps eating up the under the hood real estate

 

[borism]

That is the challenge. In the thread I cited you can see photos of some "stuffed" cracks.

 

[Paul Birkeland]

Chokes Explained

 

[Nathan]

Chokes Explained

Thanks!

In this specific application- in the Crack, what could one reasonably expect by adding a choke?

 

[Nathan]

So I am officially intrigued with the idea of adding a choke to my Crack's power supply. Seems the location is in place of the 270 ohm 5w resistor between tabs 13 and 15- which with my limited under the hood space sort of looks like a bear to get a clean connection to.

But there's another 270 ohm 5w resistor which is far easier to access- between the 1st and 2nd PS cap-  clip the leads, solder on the choke wires, done. I'm assuming there's a reason why we don't look to connect the choke to this point- why is that?

 

[Paul Joppa]

There are differences between the two locations, but they are technical and somewhat complicated. This is not a Bottlehead-supported modification, so we have not done the experiment of trying both places. You can be the first!

 

[Nathan]

Put in the choke at the last PS cap. I used 1inch stand offs to mount the choke. Soldering space was tight but not as bad as I feared. Works like a charm. Love my 'personalized' Crack