Capacitance, anyone? - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 6th February 2004, 11:03 AM   #1
diyAudio Member
 
Join Date: Sep 2002
Location: Rosmalen, The Netherlands
Default Capacitance, anyone?

Hello all,

If anybody is looking for powersupply capacitors, try BG Micro (www.bgmicro.com).
Search for "The Stubby" (68.000uF/50V).
I ordered mine two weeks ago, and I received them today. Boy, do look the business!!. I guess this means my ampchassis is going to be a bit bigger!!
Even with shipping to Europe (the Netherlands) the price is incredible (I think I payed about 6,50Euro's per can including shipping and handling).
I am making 4 channels of Aleph 5, and there are some things I still have to locate (matched sets of fets).

Regards,

Jarno.
__________________
Oemptempa petoempetapap
  Reply With Quote
Old 6th February 2004, 11:12 AM   #2
joensd is offline joensd  Germany
diyAudio Member
 
Join Date: Dec 2001
Location: Germany
capitance? does that sum up what a captain does in his job?
thanks for the hint, interesting opportunity.

You´d be better (cheaper) off to match the fets yourself.
Try Reichelt for some cheap fets. I paid 1.35€ for the IRFP240 from International Rectifier.
To be sure they come from IR (if it´s important to you) you better call them up to be safe.

Cheers
Jens
  Reply With Quote
Old 6th February 2004, 11:29 AM   #3
diyAudio Member
 
Join Date: Sep 2002
Location: Rosmalen, The Netherlands
Default Matching feets

Hello Jens,

How many fets do you need to get 2 decently matched sets of 6 fets each?

Regards,

Jarno.
__________________
Oemptempa petoempetapap
  Reply With Quote
Old 6th February 2004, 05:51 PM   #4
joensd is offline joensd  Germany
diyAudio Member
 
Join Date: Dec 2001
Location: Germany
Quote:
How many fets do you need to get 2 decently matched sets of 6 fets each?
I recall having read a lot of suggestions of how many fets you´d have to buy to get a certain amount of matched fets.
I still haven´t matched mine so...
Just do a search here and you´ll find many answers.

It definitely helps when you call the distributor or whereever you´re buying the fets and ask if they´re from the same batch.
That keeps the probability of having fets with more or less the same gate-source-voltage quite high.

Another thing is that not all fets from one amp have to be the same gate-source-voltage. You have to group the fets working as current sources and the "gain-fets" but you probably know anyway.

Cheers
Jens
  Reply With Quote
Old 6th February 2004, 05:59 PM   #5
joensd is offline joensd  Germany
diyAudio Member
 
Join Date: Dec 2001
Location: Germany
That´s for example one of those threads about matching mosfets.
You might also wanna read Nelson´s great article about mosfets.
(link is given in the thread as well)

Cheers
Jens
  Reply With Quote
Old 6th February 2004, 06:17 PM   #6
Magura is offline Magura  Denmark
diyAudio Member
 
Magura's Avatar
 
Join Date: Oct 2003
Location: Denmark, Viborg
Not to be a party killer byt those 68,000uf 50V caps are about half the size of rifa 68,000 uF 50V.

Im quite sure that if it was possible to make a good and reliable cap half the size....rifa would have made it half the size.


Magura
__________________
Everything is possible....to do the impossible just takes a little while longer.
www.class-a-labs.com
  Reply With Quote
Old 6th February 2004, 07:40 PM   #7
joensd is offline joensd  Germany
diyAudio Member
 
Join Date: Dec 2001
Location: Germany
Indeed you´re a damn party pooper, Magura.

Actually I haven´t looked at the size of the caps but at least they´re from Nichicon, a well known and one of the better cap manufacturers.
Of course size depends on temperature-rating and reliability.
Ever seen those Sikorel caps from Epcos (earlier they were manufactured by Siemens)? 105degree types that last "almost" forever.

I won´t buy any caps anyway, just bookmarked this bgmicro-shop.

Just for interest : What did you pay for shipping and all, Jarno?

Cheers
Jens - heading off for a beer
  Reply With Quote
Old 6th February 2004, 10:33 PM   #8
diyAudio Member
 
Join Date: Dec 2002
Location: Illinois, USA
This capacitor looks very similar to one manufactured by United Chemi-Con (as far as I can tell the same company as Nippon Chemi-Con) and sold by Mouser - even the same U32D style, size, capacitance, voltage rating, and temperature rating.

Mouser sells it for about $36. What's the catch? Who knows.

Jeremy
  Reply With Quote
Old 7th February 2004, 09:53 AM   #9
cHoc is offline cHoc  Netherlands
diyAudio Member
 
Join Date: Apr 2007
Send a message via MSN to cHoc
Default Re: Capacitance, anyone?

Quote:
Originally posted by Jarno
I am making 4 channels of Aleph 5, and there are some things I still have to locate (matched sets of fets).

Regards,

Jarno.
Try AHE from the Hifi.nl Forum
he sells matched fets
  Reply With Quote
Old 7th February 2004, 10:50 AM   #10
diyAudio Member
 
Join Date: Sep 2002
Location: Rosmalen, The Netherlands
Default Capacitance and FETS

Hello all,

Thanks a lot for all the replies. Regarding the FETs I have contacted Specmail (well known to all the dutch guys, I think), but I will ask AHE as well.
I have also had a look at the spec sheets of the big capacitors, they have a ESR of 9,4mOhms and a rated ripple current of 24,55A. And yes, they are by United Chemi-Con. They also make a more "elongated" type which has a ESR of 6,5mOhms and a rated ripple current of 27,67A. The type is indeed U32D. Capacitors by other brands are similar:
Panasonic G-AA: 7,7mOhm 14,27A or 14,15A (depending on case)
Nichicon NT: 27,5A (68.000uF/35V)
Nichicon NR: 36,0A

So yeah, they're just your "plain-vanilla" type capacitors, but looking at the prices of the other brands, I think they'll do just fine. I paid about $38,- shipping and handling. So all in all I paid €6,50 per can which is very little, I think.

Regards,

Jarno.
Attached Images
File Type: jpg elco's aleph5_partial2.jpg (20.8 KB, 771 views)
__________________
Oemptempa petoempetapap
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Capacitance in PSU kacernator Tubes / Valves 29 10th March 2013 08:45 PM
Too much capacitance? HaLo6 Power Supplies 24 14th June 2009 05:55 PM
PS Capacitance Puffin Chip Amps 8 3rd March 2008 10:17 AM
too much capacitance in PSU??? cbutterworth Power Supplies 0 26th October 2007 03:15 AM
How much capacitance? theAnonymous1 Solid State 4 22nd June 2004 08:01 AM


New To Site? Need Help?

All times are GMT. The time now is 04:21 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2