DoZ power supply - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 26th June 2006, 04:49 PM   #1
diyAudio Member
 
Join Date: Jun 2003
Location: The Netherlands
Send a message via MSN to starbase218
Default DoZ power supply

Hello,

My Death of Zen amplifier's power supply currently uses 2 37000uF Sprague Powerlytic 36DX capacitors per channel (so 4 in total). However, I'm not totally happy with this solution. The caps are quite big. They're rated at 75v, while the power supply delivers less then 35v. And they provide relatively little capacitance for the space they occupy.

So I'm considering replacing them by several smaller caps I found on eBay. These are also Spragues, rated at 17000 uF and 55v (82D series). Since they are a lot smaller, I can put more of them in the amps' enclosure. I was thinking of using 8 of them per channel, combined with some other Spragues I have lying around (2x 20000 uF and 40v). That provides 156000 uF total capacitance per channel, way more then I currently have, and it would reduce the ripple voltage to < 0.1v (quiscent current = 1.5 A).

But, would increasing the capacitance to this level be a significant improvement? How much capacitance do I actually need? From what I read here, 2x 37000 uF seems to be a lot allready. Has anyone tried increasing the capacitance of a class-A amp, and did it have any (audible) effect?

I'm using a single toroid transformer for both channels, which is rated at 250VA (2x25v).

Thanks in advance.
  Reply With Quote
Old 26th June 2006, 09:49 PM   #2
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
Often times power supply caps are chosen for their ripple current rating rather than the capacitance. I suspect there is very little ripple voltage already, so don't make any change until you know the ripple current rating of the alternative caps.
  Reply With Quote
Old 27th June 2006, 02:43 PM   #3
diyAudio Member
 
Join Date: Jun 2003
Location: The Netherlands
Send a message via MSN to starbase218
OK, but wouldn't the ripple current rating also improve from having many smaller capacitors instead of a few big ones?
  Reply With Quote
Old 14th July 2006, 03:58 PM   #4
diyAudio Member
 
Join Date: Jun 2003
Location: The Netherlands
Send a message via MSN to starbase218
Well, the time on that ebay item is over, and I'm thinking of re-applying my 37000uF monsters again .

But another matter concering the power supply came to mind: I use a softstart circuit, often seen on this forum (the Elektor design). It works well, but it has a rather long fall-off time (the time it takes for the capacitors to discharge and the relay to fall off). I've already blown several fuses because of that.

I've also seen some other softstart designs (e.g. Rod Elliot's P39). Do these have the same side-effect?
  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
Split Voltage Switching Power Supply for Power Amp vectorplane Swap Meet 2 23rd April 2011 11:48 PM
LTspice tool for power amp power supply component evaluation andy_c Software Tools 2 23rd August 2009 05:10 PM
Can i use a computer power supply to power audio amplifiers? destroyer X Solid State 91 25th September 2006 04:36 AM
selling high current power supply for power amps. ericpeters Swap Meet 0 14th January 2005 02:21 PM
heater supply (xformer specs are 6.3V 2.5A) as supply for a power LED? jarthel Tubes / Valves 10 21st July 2003 01:30 PM


New To Site? Need Help?

All times are GMT. The time now is 05:36 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2