Paramount coupling and parafeed caps

[bjorgens]

In process of building up my 300B paramounts and while I intend to build them stock first, I can't help but think about what lies down the pike in terms of potential tweaks.

My question is relatively simple.  Is there any material benefit from changing the coupling and parafeed capacitance values from stock?  I assume that decreasing capacitance is not advisable, but wondered if there is any merit in increasing the capacitance values [Ceteris paribus].

apologies in advance if this is a dumb question...I try to be the first person to acknowledge my own ignorance on such things..   
bryan
 

[Paul Birkeland]

Hello Bryan,

The 0.1uF coupling capacitor value is reasonably well set in stone, it in combination with the 249K resistor that follows it provides a -3dB point of about 6 Hz.  You could go slightly larger in that capacitor, but you'll just be paying more for another few tenths of a Hz, which seems less than sensible.

The parallel feed capacitor is a whole different animal, and its sizing can be optimized based on your room and speakers.  PJ recommends buying a pair of 6.8uF/630V Solens, then trying the stock 3.3uF, the 6.8uF, and the two in parallel (about 10uF) and listening for bass extension and/or bass distortion (so listen loudly). 

-PB

[bjorgens]

thanks PB!

exactly what I was looking for!  At risk of pre-dispositioning myself, based on experience do you any guesses at which way things would likely go with a smallish room and Blumenstein Orcas?

bryan

[Doc B.]

Doesn't really matter with Orcas as the sub handle the deep stuff.

[bjorgens]

not out of the gate in my case...the sub is forthcoming purchase...setup will initially just be the Orcas
B

[Doc B.]

The Orcas themselves don't go down into the 20-30Hz range, so it's not too big an issue. I run the stock caps in my big system and it gets into the low 30s with plenty of punch.