Rod Elliot's P3A considirations - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 21st September 2005, 09:26 PM   #1
Sander is offline Sander  Netherlands
diyAudio Member
 
Join Date: Oct 2004
Default Rod Elliot's P3A considirations

Hello,

Currently I'm building a Rod Elliot P3a, from Rods website sound.westhost.com. My problem is that I don't have enough knowledge about capacitors to chose the right one for its purpuse.

There are many different types of capacitors such as, elctrolytic, MKP, cermamic, etc. Could you please help me deciding wich type I should use at which place? I would like to know the main purposes en performance areas of the different types. Thanks in advance!

Click the image to open in full size.
  Reply With Quote
Old 21st September 2005, 09:46 PM   #2
diyAudio Member
 
JensRasmussen's Avatar
 
Join Date: Jul 2002
Location: Denmark - Jutland
Send a message via ICQ to JensRasmussen Send a message via MSN to JensRasmussen
I'm pretty sure that Rod will send you a parts list along with the PCBs for the project

\Jens
  Reply With Quote
Old 21st September 2005, 10:09 PM   #3
diyAudio Member
 
apassgear's Avatar
 
Join Date: Nov 2002
Location: Via del Mar, Torreon
Some suggestions for starts:

C1: MKP or some would like Black Gate lytics
pf values: Polyestirene or MKP, for lower values you can also use Silver Mica.
nf values: MKP or Mylar films.
uf values (other than C1) use electolytics

In any case check the footprint of your selections to see if they match your PCB.
  Reply With Quote
Old 22nd September 2005, 04:16 AM   #4
diyAudio Member
 
still4given's Avatar
 
Join Date: Oct 2004
Location: Victorville, CA
Looks like C1 is polarized, doesn't that mean it has to be an electrolytic?

Oops, for the BOM

"C1 may be a standard electrolytic capacitor if desired. If a polarised electro is used for C1, the polarity is not shown on the overlay, but is clearly indicated on the overlay drawing.
"

Blessings Terry
__________________
X-BoSoZ, B1 Mezmerize, P101, Symasym, KSA 50, Aleph-X, Leach Low TIM, Leach Superamp, Dx MKIII, Super A, Honey Badger, JLH 1969, Gainclone. FetZilla, Peeceebee, VSSA PMI & jkuetemann, SKA GB150, Ovation nx & sx, AX&SX-14, TMG8, Slewmanster w/CFA-XH, Wolverine, Spooky, Symasui, Low TIM hybrid
  Reply With Quote
Old 22nd September 2005, 08:12 AM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
C1 should be a non polar electrolytic or back to back polarised of double the capacitance value.
It would be far better to use a film cap here instead but MKP will be much larger and cost considerably more.
The builder decides!!!
Ceramic would never be used in the audio stages due to variable capacitance as the voltage varies. However they are unbeatable in decoupling of the hi frequency rubbish on the PSU etc where they see an almost constant (DC) voltage.
The film type usually perform better than any of the electros even black gate. Some film are better than others. Polypropylene, polystyrene and teflon are of the highest quality,
Polyethylene and polycarbonate are the next level down. Then there are a few others.
Try a search for a much more full report on capacitor quality
__________________
regards Andrew T.
  Reply With Quote
Old 22nd September 2005, 09:16 AM   #6
Account Disabled
 
Join Date: Aug 2004
Location: Earth
C1 simply isn't necessary as long as there's no DC coming from upstream! It's a case of best C is no C.

Cheers,
Greg
  Reply With Quote
Old 22nd September 2005, 01:18 PM   #7
diyAudio Member
 
Join Date: Jul 2005
Location: Quebec, Canada
Here is my P3A BOM with part numbers from DigiKey.

I haven't built mine yet, but soon ...
Attached Files
File Type: zip p3a bom.zip (2.5 KB, 199 views)
  Reply With Quote
Old 22nd September 2005, 04:43 PM   #8
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi Amplifier Guru,
the dc blocking cap C1 also stops bias from one amp interacting with the bias from another if more than on power amp is connected to the same source.
__________________
regards Andrew T.
  Reply With Quote
Old 22nd September 2005, 05:26 PM   #9
rushi is offline rushi  Finland
diyAudio Member
 
Join Date: Oct 2003
Location: Finland
Sander: Do _NOT_ use electrolytic as a C1. Use Polypropylene (Aydyn-Cap or similar) or better, Paper-In-Oil caps. It doesn't have to be 4,7F, 1...2,2F works fine. It won't fit on PCB, but who cares?
All electrolytics should (must, imo) be low-ESR types, Black Gate or something (OS-CON more preferably).
Mylar, MKP (Polypropylene), Silver-Mica or polystyrene for smaller ones.

That's how I would do it.
  Reply With Quote
Old 22nd September 2005, 06:01 PM   #10
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
You can use a non-polarized electrolytic for C1. Or polarized. Disregard most of the hype about must-not-use, 99.9% of us can't hear the difference. Those that claim they can probably can't.
However, the output transistors can make a big difference.
  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
DOZ - Death of ZEN amp from Rod Elliot hifimaker Pass Labs 26 6th April 2012 06:09 PM
Rod Elliot P37? roger-k Solid State 21 7th October 2006 08:37 PM
Rod Elliot's new Mosfet Amp AKSA Forum Problems 1 20th February 2004 08:42 AM
Another new Rod Elliot amp! p3B! Mattyo5 Solid State 20 27th January 2004 12:45 PM
Elliot's 60W AB amp mrpibb Solid State 2 29th April 2001 10:51 PM


New To Site? Need Help?

All times are GMT. The time now is 12:49 AM.


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