Chip amp power supply- a beginners guide - Page 71 - 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 19th April 2012, 02:24 PM   #701
jazko is offline jazko  United Kingdom
diyAudio Member
 
Join Date: Sep 2009
Location: Manchester
Quote:
Originally Posted by john blackburn View Post
alh081

Try here Building a Gainclone chip amp power supply.

Could a moderator edit the dead link in the first post of the thread please?

John
For some reason I cannot see the pictures. Am I the only one?
  Reply With Quote
Old 19th April 2012, 04:39 PM   #702
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
It's taking forever to download. Some of the pics are visible.

It completed download in about 3mins.
Only one pic missing. click to reload worked almost instantly. Page now complete.
__________________
regards Andrew T.

Last edited by AndrewT; 19th April 2012 at 04:43 PM.
  Reply With Quote
Old 20th May 2012, 05:48 PM   #703
diyAudio Member
 
Join Date: May 2010
Hey all,

As it is here my first post, I would like first to thank you for the help you've already given to me.

I got months ago, a amp6 Basic from 41hz (here) and planned to use it with my turntable. So, I got the "Phono-M pre-amp" from Thel Audio (here) with its transformer. I thnk it would be a good idea to put it in a separate housing, so that I could use it with other amp, and so comes my questioning :

- Is it possible to use a phono preamp with any amp? If not, which parameters are affected please?
- Is it possible to power the preamp with the amp's power supply? (The amp datasheet says : "Requires single 13.5V power source")

Thanks in advance, regards.

Ps : I hope my message won't be considered as indecent because it's been posted before the last thread seemed to be really treated. But as the last message had now been sent a month ago, I considered it wouldn't be that impolite.
  Reply With Quote
Old 29th July 2012, 01:26 PM   #704
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
I would like to add the ground loop breaker to my SMPS powered GC.

Click the image to open in full size.

I know that I can't join the 0v rails of the two SMPS modules so have to treat this as two monoblocks even though they share the same wooden case. So I need a separate loop breaker for each channel and propose to do the following:

Click the image to open in full size.

Blue line between SMPS and amp is 0v, red is positive voltage and black is negative voltage.

The side of the loop breaker that goes to earth would be bolted to the metal chassis of the SMPS module (that is in turn connected to mains earth).

Does this arrangement appear OK/safe?
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 6th September 2012, 03:47 PM   #705
diyAudio Member
 
Join Date: Dec 2011
Location: Ohio
Default PSU for TDA8950TH chip amp.

After spending over 4 days reading all 71 pages of this thread and doing a search I am still stuck. I bought a 2.1ch amp based on the TDA8950TH chip and am having troubles figuring out the PSU for this amp.
(Hopefully this shows up as the Ebay link.)
YJ 2.1 TDA8950TH 150W+150W+250W Class D Amplifier board

This amp runs one chip in stereo and one in BTL mode. As stated in the item description it requires a CT trans of between 15Vac-0-15Vac to 28vac-0-28vac but does not give any details of what the Va needs to be. And it has an on board bridge rectifier and smoothing caps. This is where it differs from what I have read others have been doing.

I need help finding out what the overall Va for the Trans needs to be. I have been told by many people that it needs to be anywhere from 300Va to 800Va.( The 800Va quote came from a toroid supplier.) I need to get a definitive answer on what Toroid I need to order to bring this board to life.

After doing many searches all over the web I did not find any info on this particular board being used in a working system to get ideas for the PSU being used.
Any help will be appreciated and for others looking to build off of this board I will be doing a full build thread including the PSU info.
Thanks for your help.
  Reply With Quote
Old 6th September 2012, 06:58 PM   #706
diyAudio Member
 
Join Date: Dec 2011
Location: Ohio
I should add that this will be used in the US so 115vac primaries and the load will be 2x8ohm for the stereo channels and 2x4ohm wired for a 8ohm load for the sub channel.
  Reply With Quote
Old 6th September 2012, 08:41 PM   #707
diyAudio Member
 
Join Date: Mar 2007
Location: California
Quote:
Originally Posted by biggerrigger View Post
After spending over 4 days reading all 71 pages of this thread and doing a search I am still stuck. I bought a 2.1ch amp based on the TDA8950TH chip and am having troubles figuring out the PSU for this amp.
(Hopefully this shows up as the Ebay link.)
YJ 2.1 TDA8950TH 150W+150W+250W Class D Amplifier board

This amp runs one chip in stereo and one in BTL mode. As stated in the item description it requires a CT trans of between 15Vac-0-15Vac to 28vac-0-28vac but does not give any details of what the Va needs to be. And it has an on board bridge rectifier and smoothing caps. This is where it differs from what I have read others have been doing.

I need help finding out what the overall Va for the Trans needs to be. I have been told by many people that it needs to be anywhere from 300Va to 800Va.( The 800Va quote came from a toroid supplier.) I need to get a definitive answer on what Toroid I need to order to bring this board to life.

After doing many searches all over the web I did not find any info on this particular board being used in a working system to get ideas for the PSU being used.
Any help will be appreciated and for others looking to build off of this board I will be doing a full build thread including the PSU info.
Thanks for your help.
Quickie calculation is that the transformer VA should be at least equal to the sum of the max power of the chip amps it will be powering PLUS the amount of waste heat that is dissipated by the IC when powering the speaker load. You get this from the datasheet. For a class AB amplifier, this can be as much as the same as the power delivered to the load. The TDA8950TH is a class-D amplifier however, and Figure 19 from the datasheet shows that the worst case is for the 2x4 ohm load, where dissipated power can range up to about 30W. Let's say you use a transformer with 24-0-24VAC secondaries. This will get you about +/-35VDC rails. According to the datasheet, the TDA8950TH can deliver about 200W into the 8 ohm BTL load and 100W/ch (another 200W total) into two 4 ohm loads. So, adding all this up, we get 200+200+30+30 or about 450W. So, I would go for a 500W or higher rated power supply that can provide +/-35VDC supply rails. This could be a linear or switching supply. Since you are asking about a transformer, I assume you mean a linear supply, so you also need to figure out how large the filter capacitors should be. A quick rule of thumb is that you need 10,000uF per rail, per 100W into 4 ohms. IN this case we have FOUR times that (stereo = 100+100, and bridged mono = 100+100) so you need about 40,000uF filter caps, one per rail. With such a large transformer and caps, you will want to think about a soft start module because there will be some inrush with this setup.

Hope that is helpful for you...

-Charlie
  Reply With Quote
Old 7th September 2012, 03:41 AM   #708
diyAudio Member
 
Join Date: Dec 2011
Location: Ohio
Mr. Charlie
Thank you so much for your help. This is just the kind of info I was looking for. In your opinion what direction would you go with the supply linear or switching. This amp is being used in a high power portable boom box of sorts. And that's why I am leaning towards the switching supply for the weight savings. But I have read in the past that chip amps do not play well with switching supply's over the long haul and that I would be better going with a linear supply.
Thanks again for your help.
Aaron
  Reply With Quote
Old 7th September 2012, 08:58 AM   #709
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
portable boom box.
Have you watched the "world's strongest man"?

They are introducing a new test. Carrying the battery pack for a 100W+100W portable power amplifier.
__________________
regards Andrew T.
  Reply With Quote
Old 7th September 2012, 02:19 PM   #710
diyAudio Member
 
Join Date: Dec 2011
Location: Ohio
I pack around pro sound subs and tops by myself so this really should be no different. It should be a little easier because of the more compact size and properly placed handles. Definitely not something I will put on my shoulder and walk down the street with.

I provide sound for the lake resort that I live at about 10 times a year. I am building this portable system to help keep it easy when it comes time to provide sound. Instead of hitching up my trailer and hauling all of my gear down setting up tearing down ect. I can just toss the portable on the back of the golf cart and be set up by plugging it in the wall at the pavilion plug in a mic and I am in business. Clean up is just as easy.

I will have a mic input as well as a MP3 input on this portable unit. I am going to leave space for a group of lipo packs in the very bottom of the unit but I will not be running them at first. That is another bridge that I will cross down the road when I figure out the best way to implement them into the system.
  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
A Beginners Guide to Enclosure Alterations Bork Multi-Way 7 12th January 2009 02:10 AM
beginners ecl82 power supply emil_86 Tubes / Valves 15 25th September 2004 05:20 AM


New To Site? Need Help?

All times are GMT. The time now is 02:25 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