3 Ohm amplifier - Newbie - 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 8th February 2013, 04:26 PM   #1
diyAudio Member
 
Join Date: Feb 2013
Default 3 Ohm amplifier - Newbie

Hi,

I was wondering if it was possible to make a very simple amplifier for a 3 Ohm speakers, I'm upgrading my home cinema to Blu Ray but no single unit Blu Ray player is sold with a home cinema amplifier built in and no home cinema amplifier is rated below 4 Ohms. So rather than immediately buying a whole new surround sound system I though I'd first see if i could DIY it, So i came here
I'm guessing it would be chip related so i posted this here, if i'm in the wrong place please redirect me.
I have made simple guitar amps before but i'm not 100% about this kinda stuff so go easy on me!!

Thanks in advance

Gareth
  Reply With Quote
Old 8th February 2013, 10:38 PM   #2
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Say something about your 3 ohm speaker.
  Reply With Quote
Old 8th February 2013, 10:43 PM   #3
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Should be fairly easy for any of the car audio chip amps.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 8th February 2013, 11:15 PM   #4
johnr66 is offline johnr66  United States
diyAudio Member
 
Join Date: Mar 2009
About any chip amp you can find will handle 3 ohms. All you have to do is set the supply voltage so that current is reduced enough for the load. Next question is the wattage you need / wattage speaker can handle.

Last edited by johnr66; 8th February 2013 at 11:19 PM.
  Reply With Quote
Old 10th February 2013, 02:00 AM   #5
diyAudio Member
 
Join Date: Feb 2013
Ok thanks, can you suggest any particularly good chips?? Well in the spec it doesn't say what wattage the speakers can handle but it does say each output is 140 W, which to me sounds very wrong... Consisting I can pretty much blow the windows out with my 100W guitar amp!!! Here's the manual for anyone who can shed a little light on what wattage the speakers are http://pdf.crse.com/manuals/3283036113.pdf the spec is on page 90. That's so far I'll get researching chips

Gareth
  Reply With Quote
Old 10th February 2013, 03:08 AM   #6
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Fine as a beginning.

1) just curious, how come you have the speakers but not the original amplifiers?

2) do you have all 6 of them?

3) the manual is confusing, (probably on purpose) but it *seems* to have 6 x 140W amplifiers. Weird.

4) the speakers *seem* to handle that power, although quite probably the driving amps have limiters set to, say, 40 to 60W.

5) if you really need to build a 6 channel amp, each one can be run by an LM3886, with somewhat reduced PSU voltage as correctly suggested by Johnr66 , for some 40W per channel. Very respectable and about the same as the original system.

6) *or* for a lower power (but maybe still enough) system, about 6 to 8W per channel, you can use 6 x TDA2003, which are *happy* driving down to 2 ohms loads all day long.
What sofaspud said.

7) last but not least: 100W of distorted guitar through efficient guitar speakers is more than a match for a system driving very inefficient and small 2.5" speakers (and 1 one lonely 7 inch woofer).
  Reply With Quote
Old 10th February 2013, 01:25 PM   #7
diyAudio Member
 
Join Date: Feb 2013
Quote:
Originally Posted by JMFahey View Post
Fine as a beginning.

1) just curious, how come you have the speakers but not the original amplifiers?

2) do you have all 6 of them?

3) the manual is confusing, (probably on purpose) but it *seems* to have 6 x 140W amplifiers. Weird.

4) the speakers *seem* to handle that power, although quite probably the driving amps have limiters set to, say, 40 to 60W.

5) if you really need to build a 6 channel amp, each one can be run by an LM3886, with somewhat reduced PSU voltage as correctly suggested by Johnr66 , for some 40W per channel. Very respectable and about the same as the original system.

6) *or* for a lower power (but maybe still enough) system, about 6 to 8W per channel, you can use 6 x TDA2003, which are *happy* driving down to 2 ohms loads all day long.
What sofaspud said.

7) last but not least: 100W of distorted guitar through efficient guitar speakers is more than a match for a system driving very inefficient and small 2.5" speakers (and 1 one lonely 7 inch woofer).
1) I have the amplifiers, but they are in the DVD player. I want to upgrade to a Blu Ray player which won't have amplifiers in it, so i will need something to amplify the outputs.

2)I have all 6 speakers, if that's what you're asking. The amps are hidden inside my DVD player which I'm upgrading.

3)Yes I was somewhat confused as that is thee only conclusion i could come to...

4)To be honest I'm not after the loudest system on the planet...

5)Ok so what kind of PSU voltage are we looking at?

6)Yea i'll probably go for this option as i'm not looking for a very powerful system. something like this do? 8W TDA2003 /TDA2002 Monophonic Power Amplifier Kit New | eBay

Although I will probably end up making it myself, it's much more fun that way

7)I understand that I was just saying how I thought they sounded a little overpowered.

Thanks for that help

Gareth
  Reply With Quote
Old 10th February 2013, 03:20 PM   #8
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
People get angry at me for no helping people so i would give it a go:
You can hook up you bluray player output to the amp without any internal modification

And wait if you want to build your own power amp you will need 40w or so for subwoofer is sattelites are 10w each,for wich i sugest an tda1562q and for sattleties still use tda 2003 ot tda 1517, the 2003 is very warm sounding i have a kit i tried building a few but that didnt work out since nothing works for me since im unlucky an pessimistic

Last edited by PetruV; 10th February 2013 at 03:32 PM.
  Reply With Quote
Old 10th February 2013, 03:22 PM   #9
diyAudio Member
 
Join Date: Feb 2013
Quote:
Originally Posted by PetruV View Post
People get angry at me for no helping people so i would give it a go:
You can hook up you bluray player output to the amp without any internal modification
Yes but i will not have 5.1 surround sound it will just be left-right as there is no 5.1 input, just a jack-in
  Reply With Quote
Old 10th February 2013, 11:16 PM   #10
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Dear GAFAAAAA , with the best intentions, before taking advice from PETRUV, first check who are you dealing with.
And what mess you can get into, just by slightly displeasing him.
lm1875 fizzing away probelm
If you dare, read the full thread, from the beginning, also checking the "engineering level".

Back to your problem, since you already have a system perfectly adapted to your speakers, try to use it as much as possible.
I'm specially worried at the non standard speaker connectors (obviously meant to keep you "tied" to their system.
How will you connect your present speakers to "something else"?
I'll check the manual, maybe besides the "regular" stereo RCA in, it has some direct digital or something input which allows for external input which later is decoded to 5.1 or something.
Not exactly my area.
Absolute worst case, listening 2:1 with properly matched and loud speakers and amps is not that bad.
Is it?
  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
Bridging two 300W in 8 ohm amplifier to drive 1200W in 8 ohm rhythmsandy Solid State 3 2nd December 2012 06:47 AM
Connecting an 8 ohm svc sub to a 4 ohm amplifier kaadye Subwoofers 15 24th May 2010 08:07 PM
4-ohm Speakers on 6-ohm Amp? (newbie question) diesel_88 Multi-Way 23 25th October 2007 09:54 AM
Wanted: DIY amplifier builder with experience. I need a 0.7 ohm stable amplifier Audiophilenoob Swap Meet 34 17th May 2005 12:58 AM
Newbie Question: Cheapest route to 2 ohm stable Ignite Solid State 4 31st October 2001 07:50 PM


New To Site? Need Help?

All times are GMT. The time now is 02:33 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