Coupling cap question.

heiney9
heiney9 Posts: 25,197
edited October 2010 in DIY, Mods & Tweaks
I have a Norh SE-9 tube amp. The input tube coupling caps are .25uF 200V WIMA's (those red square caps). I read over at Audiocircle of someone replacing them with .33uF 450V Auricaps. I really like Auricaps.

My question is what effect will the extra capacitance have in the circuit? Auricap also make a .22uF 450V but that is a lesser value than the stock. I thought it might be better to go a bit larger. Obviously the voltage rating of the Auricaps is just fine.

Thoughts, comments, idea's. Having second thoughts going with something that much larger.

H9

P.s. I already have the .33uF Auricaps
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
Post edited by heiney9 on

Comments

  • FTGV
    FTGV Posts: 3,649
    edited October 2010
    The larger cap will mean the low frequency roll off will start slightly lower.If you know the impedance the cap is looking into it 's easy to calculate the change.http://www.muzique.com/schem/filter.htm
  • schwarcw
    schwarcw Posts: 7,339
    edited October 2010
    Maybe a little more bass?
    Carl

  • FTGV
    FTGV Posts: 3,649
    edited October 2010
    More bass but it would be below below audibility assuming high enough input impedance. Using 100k ohms as an example .33uf would result in a corner frequency of 4.8 hz and with .22uf it would be 7.2hz.So both caps would be usable with the example input impedance of 100k.
  • heiney9
    heiney9 Posts: 25,197
    edited October 2010
    Thanks guys, I don't have a schematic, but I can post some high rez pics where the caps are. But it sounds like it'll be alright to use a value close but not exact.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!