Gainclone questions - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 20th April 2003, 04:19 AM   #11
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
I added 10,000 to my 1.000u rails and it actually stopped shining. And cables from PS to the amp make big difference indeed. I choose the cables according to the feedback resistor type I use to achieve most neutral sound.

Here's the little graph showing different power levels with regard to supply voltage for LM3875. My preference now is about 22v AC with 400VA Plitron. It seems to be more dynamic than 18V rails gainclone. You also stated interest in using OPA541. I tried OPA549 and prefer LM3875, because it produces more emotions with the music. OPA maybe sounds more correct, but more lifeless also.
Attached Images
File Type: gif po.gif (11.4 KB, 1129 views)
__________________
www.audiosector.com
Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it. - JC
  Reply With Quote
Old 20th April 2003, 07:04 PM   #12
diyAudio Member
 
Join Date: Aug 2002
Location: USA
If you had only Parts Express and Mouser to order from... which caps and resistors would you go with? I am putting a limited, unlimited budget up here. I mean, I cannot spend $100 on this... but I figured it up with a Solen 3.3uF input cap, Vishay/Dale 1% 1/2W resistors, a cheap ($2.35) 10k Xicon audio pot from Mouser, Nichicon UPW power caps, and fairly cheap gold plated RCA and binding posts. The total was about $30.

What power caps are best from Mouser? Anything I should change parts-wise?
  Reply With Quote
Old 20th April 2003, 07:18 PM   #13
Philo is offline Philo  United States
diyAudio Member
 
Join Date: Jul 2002
Location: Ever sunny San Diego
Why only them? For your filter caps I would go with the Panasonic FC 1000uF/50V for $2.40 apiece from DigiKey. You can Dale NH65 resistors from them as well and get some Mills 10Kresistors from PartExpress. Input caps are up to your preference but a nice polypropylene or polycarbonate from either of the companies would work well.
__________________
Philip
"If you didn't make it with your own two hands, its not really yours".
  Reply With Quote
Old 20th April 2003, 10:33 PM   #14
diyAudio Member
 
Join Date: Feb 2003
Location: GTA
noticed apexjr has panasonic 1000uf 100v very cheap
must be TS series based on the 100v
anybody knows how they compare to the touted FC series?
__________________
intentionally blank
  Reply With Quote
Old 20th April 2003, 11:00 PM   #15
diyAudio Member
 
Join Date: Jul 2001
Location: The Netherlands


When are people going to realize that a resistor from output to supply rail is NOT biasing anything to Class A in a gainclone?
  Reply With Quote
Old 21st April 2003, 02:30 AM   #16
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
If your source doesn't pass any DC, forget Solen coupling cap and you save even more. Also Solen might not be a best choice here if you care about good sound. I would probably also use Panasonic FC caps and Dale/Vishay resistors.
__________________
www.audiosector.com
Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it. - JC
  Reply With Quote
Old 21st April 2003, 02:39 AM   #17
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Quote:
Originally posted by tschrama
When are people going to realize that a resistor from output to supply rail is NOT biasing anything to Class A in a gainclone?
Well it is a half-assed class-A. It does keep half the complimentary output conducting througout the full 360 degrees.

se
  Reply With Quote
Old 21st April 2003, 07:17 AM   #18
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
It does keep half the complimentary output conducting througout the full 360 degrees.
But at what level? We're talking 20mA or so through the biasing resistor, right?
  Reply With Quote
Old 21st April 2003, 02:21 PM   #19
miguel2 is offline miguel2  Portugal
diyAudio Member
 
Join Date: Jun 2002
Location: Portugal
when using an electrolytic as input cap, does it has to be non-polar?

I made a gainclone with the OPA541 and found it to be nothing special. Used BC resistors and film caps and samsung electrolytics, nothing fancy, so maybe the chip is not to blame...

Miguel
  Reply With Quote
Old 21st April 2003, 02:24 PM   #20
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
How much filter capacitance did you use? The coupling cap can be polar, but you can also remove it completely, if you don't have nothing fancy to us in that location. Just check DC offset to be safe.

Making a gainclone to sound special is not that easy.
__________________
www.audiosector.com
Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it. - JC
  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
Gainclone: 2 newbie questions... Bassterror Chip Amps 10 3rd April 2006 02:23 AM
Parallel gainclone questions ejn327 Chip Amps 6 6th January 2005 05:28 PM
Questions on gainclone powering a sub mFinalHeaven Chip Amps 6 17th August 2003 07:59 AM
very simple gainclone questions wrl Chip Amps 4 23rd June 2003 07:01 AM
More gainclone questions :) elizard Chip Amps 48 25th April 2003 07:47 PM


New To Site? Need Help?

All times are GMT. The time now is 01:44 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