What Input cap for amp3 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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 2nd September 2005, 05:10 AM   #1
MrDodo is offline MrDodo  Mauritius
diyAudio Member
 
MrDodo's Avatar
 
Join Date: May 2005
Location: Rose Hill
Default What Input cap for amp3

I don't know which input cap to choose for the amp3, as Jan himself seems undecided and provided us choice of ceramic and electrolytic.
Based on you experience which one should I choose?
Or should I go for another electro like BG or polyster or polypro.
Jan also suggested 0.1uf parallel for the input to improve HF. Has anyone tried this to good results.
I have read somewhere that electro should not be used as input cap, same with ceramic. What should I do then?
Thanks.
  Reply With Quote
Old 2nd September 2005, 05:38 AM   #2
BWRX is offline BWRX  United States
diyAudio Moderator Emeritus
 
Join Date: Jan 2005
Location: Pennsylvania
i used the 2.2uF ceramic and have no complaints regarding the sound. i haven't tried the electrolytic and don't plan to

a lot of people have tried other caps. i think i remember reading about it in some pretty recent threads too. i would look for them but i'm off to finish up recasing my amp3!
  Reply With Quote
Old 2nd September 2005, 07:20 AM   #3
diyAudio Member
 
tommytube's Avatar
 
Join Date: Sep 2004
Location: Eastern Oregon
Default AMP3 caps

So far I've tried the supplied ceramic, a 2.2uf tantalum, a russian 1.5uF PIO and now have a 4.7uf Taurus polypro bypasses with a .33uF Vitamin Q. All I can say is there are many options. The PIO bypasses I recently installed added a bit of body and took away a bit of the plastic sound of the polypro caps.....it's a nice mix of smooth, detailed sound that has great bass.

Here's a pix inside my Amp3 just before adding in the VitQ bypasses.

BTW, I love the sound of this thing. It really gets my toes a tappin'.
Attached Images
File Type: jpg amptop1.jpg (77.8 KB, 316 views)
  Reply With Quote
Old 2nd September 2005, 09:09 AM   #4
MrDodo is offline MrDodo  Mauritius
diyAudio Member
 
MrDodo's Avatar
 
Join Date: May 2005
Location: Rose Hill
TommyTube,
Wow, I'ver never even heard about the caps you are mentioning.
... on the other side I'm a noob so maybe this explains that.
They must be pretty rare and/or expensive exotic caps. Where you get these? I'm pretty impressed with the parts you used inside your amp. What's that big black cap?
Anyone using the more common Black Gates (?!) or anything, who thinks its worth the cost compared to the supplied ceramic?
  Reply With Quote
Old 2nd September 2005, 04:45 PM   #5
diyAudio Member
 
tommytube's Avatar
 
Join Date: Sep 2004
Location: Eastern Oregon
Default cap choices

Most of the ones I mentioned are on ebay commonly. The green PIO russians are around a lot. I bought a dozen of the lesser known Tauras polypros from a guy in England off ebay. Never heard of them either and wanted to try them. Very cheap in price, pretty good sonics.

BG's some like for coupling, I believe there are better choices. But most of the choices I like won't fit on the board so you need to put these off board. I put the input coupling caps directly on the input RCA's and then wire the output onto the Amp3 board at the normal input. Just jumper over the caps on the board so the signal gets into the SMD resistor and onto the tripath's input.

The large black cap is part of my capacitor board in the power supply. Jan mentions using up to 20,000uF capacitance for a 12V SLA battery supply. I just put a bunch of Nichicon Muse KZ's in parallel as well as the big black one (a larger value Solen), these are all between the +12V input and ground. I used both polypros and electrolytics on the cap board to try and get the benefits from both types of caps.

If you wanted a good quality input coupling caps, I'd go either plastic/polypro type or paper in oil. Getting a large enough PIO is not as easy as finding a larger plastic caps. Use Audience, Relcaps, Kimber, Cardas, Sonic....all these are commonly available and nice caps. What you need to realize is many of the best couplers are rated much higher than 50V and but can still be used in your amp.

If you want a path of least resistance, get the audience and try that. Most love it's sound and it's price is reasonble....but good poly's are still at least 5 to 15 dollars a piece. Some much more.

Have fun with it. Ebay is a good source of many exotic caps...especially if you don't mind dealing with the Ukrainian guys.
  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
FS: Completed AMP3 theAnonymous1 Swap Meet 3 19th December 2006 10:18 PM
FS:(2) 41hz Amp3 sfogg Swap Meet 2 24th January 2006 04:52 PM
Amp3 capacitance filholder Class D 5 10th August 2005 08:01 AM
4.7uf BG N in T-amp or Amp3 t. Class D 7 14th July 2005 04:59 PM
41Hz AMP3 Pano Class D 12 25th April 2005 09:07 PM


New To Site? Need Help?

All times are GMT. The time now is 08:21 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