one thousand mic electrolytic

tubefrk · 3492

0 Members and 1 Guest are viewing this topic.

Offline tubefrk

  • Jr. Member
  • **
    • Posts: 19
on: October 23, 2012, 09:36:54 AM
Hello all, did I over hear someone talking about replacing the one thousand mic.  electrolytics in the Quicke with some film Caps??????



Offline corndog71

  • Sr. Member
  • ****
    • Posts: 593
Reply #1 on: October 23, 2012, 10:27:28 AM
Yep, I built an alternate souped up version and replaced the 1000uF caps with Erse Pulse X 51uF 250V caps.  They are a LOT bigger caps.

The world was made for those not cursed with self-awareness.

Rob


Offline tubefrk

  • Jr. Member
  • **
    • Posts: 19
Reply #2 on: October 31, 2012, 10:40:47 AM
Thank you mister Dog.   Did you do anything to the circuit I need to know about?   Thanks,  Mike



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19319
Reply #3 on: October 31, 2012, 11:13:58 AM
You can go a bit lower than 1,000uF, I think PJ said 50uF or bigger is OK.  Voltage rating on this cap can be 5+ VDC.  FWIW, Parts Connexion has a ton of audio grade electroyltics that will work in this position, many of them are not particularly expensive (we used the 1000uF/35V cap because it was already in our inventory).

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline corndog71

  • Sr. Member
  • ****
    • Posts: 593
Reply #4 on: October 31, 2012, 02:46:49 PM
I went as low as PJ suggested with the idea that if it was lacking then I would go back higher.  I mostly wanted to try a film cap versus electrolytic.  But I've been really happy with the sound.  Bass lines are tight and well defined.  Music sounds a bit faster and livelier compared to the stock caps in my original quickie.  I'm still curious to try a higher value sometime down the road.  Maybe try some bypass caps.

Here's my overbuilt quickie:

http://www.bottlehead.com/smf/index.php/topic,3332.0.html

The world was made for those not cursed with self-awareness.

Rob


Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 5751
Reply #5 on: October 31, 2012, 05:50:43 PM
The bias voltage is about 2 volts. There are also those polymer electrolytics like OsCons that have a good reputation (low ESR up to high frequencies) and are available with low voltage specs like 4v. Normal practice with electrolytics is to run them at 50% to 80% of rated voltage; however the only documented problem with lower voltage is that they can lose their high voltage capability - you can't take the 35v cap out of a Quickie and count on it to take 30v in a SEX amp.

There are some lower-voltage Mylar caps that are small with high capacitance, and not too expensive. They might be worth listening to.

Paul Joppa


Offline Grainger49

  • Hero Member
  • *****
    • Posts: 7175
Reply #6 on: November 01, 2012, 03:12:52 AM
   .  .  .    the only documented problem with lower voltage is that they can lose their high voltage capability - you can't take the 35v cap out of a Quickie and count on it to take 30v in a SEX amp.   .   .   . 

Would this be a case of capacitor forming?



Offline earwaxxer

  • Hero Member
  • *****
    • Posts: 1336
Reply #7 on: November 01, 2012, 06:05:14 AM
Hello all, did I over hear someone talking about replacing the one thousand mic.  electrolytics in the Quicke with some film Caps??????

I first replaced the electrolytic with a Elna Silmic ll that I had laying around. Then I went with the Mundorf MKP 56uF. I think I remember an improvement in sound with the film. I'm sticking with the MKP. Not sure if it makes sense going crazy on this cap.

Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.


Offline E.T.

  • Newbie
  • *
    • Posts: 8
Reply #8 on: November 01, 2012, 07:27:27 AM
You can go a bit lower than 1,000uF, I think PJ said 50uF or bigger is OK.  Voltage rating on this cap can be 5+ VDC.  FWIW, Parts Connexion has a ton of audio grade electroyltics that will work in this position, many of them are not particularly expensive (we used the 1000uF/35V cap because it was already in our inventory).

-PB

Do you happen to gotta list of said audio-grade electrolytics?  I've used Elna Silmic II's and I think they sound real purty, but that's the only brand I know of.



Offline earwaxxer

  • Hero Member
  • *****
    • Posts: 1336
Reply #9 on: November 01, 2012, 07:36:22 AM
Parts Connection has the good stuff! I'm not sure you will do significantly better than the Elna, in an electrolytic. I would go film.

Here is an electrolytic cap test:
http://tech.juaneda.com/en/articles/electrolyticcapacitors.html

Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.


Offline corndog71

  • Sr. Member
  • ****
    • Posts: 593
Reply #10 on: November 01, 2012, 11:58:32 AM
The reason I wanted to try a film cap was because the ESR is typically a fraction of what you'll find from an electrolytic cap.  I'm no expert but I've read with regards to power supplies that keeping the ESR low is desirable.   I'm pretty sure I hear a difference.

The world was made for those not cursed with self-awareness.

Rob