I have 12V on a PC PSU to build an 2.1/2.0 audio amplifier!
I've trawled through loads of old forum posts bad, quality youtube videos and truthfully they all seem the same to me after a day of looking.
Im trying to make general speakers for films and music on my PC
Heres the chips (or series of) I have lined up:
TPA20XX
TDA7294/TDA7297
STA540
TPA31XXD2
But how do I choose!?!?
In your wisdom which sounds the best?
Which gives the loudest sound for the voltage?
Which ones have you had the best luck with?
Any personal preference/experience?
least external components?
Best for my use?
Or a chip I've missed in my frantic searching
Sorry guys! I'm pulling my hair out here!
Will
I've trawled through loads of old forum posts bad, quality youtube videos and truthfully they all seem the same to me after a day of looking.
Im trying to make general speakers for films and music on my PC
Heres the chips (or series of) I have lined up:
TPA20XX
TDA7294/TDA7297
STA540
TPA31XXD2
But how do I choose!?!?
In your wisdom which sounds the best?
Which gives the loudest sound for the voltage?
Which ones have you had the best luck with?
Any personal preference/experience?
least external components?
Best for my use?
Or a chip I've missed in my frantic searching
Sorry guys! I'm pulling my hair out here!
Will
Well the available voltage determines the power achievable. Watts is V squared divided by R (the speaker) so 12 volts means a theoretical max of,
12/2 which is 6. That's the peak voltage swing available. Plus 6 and 'minus' 6. The RMS value is vpeak divided by root2 which is 4.24 volts. Power is therefore (4.24*4.24)/8 which is 2.2 watts. 8 is the typical speaker impedance. Not a lot is it
In practice it will be even less because the amp won't swing the full 12 volts because of internal losses.
Can't advise you on which chip is best for such a low voltage application.
I suspect Class D (which typically uses a bridged output stage) will give the best performance for what you are after. It efficient, and the bridged output means it can swing twice the supply voltage across the load... I'll let you work that one out
12/2 which is 6. That's the peak voltage swing available. Plus 6 and 'minus' 6. The RMS value is vpeak divided by root2 which is 4.24 volts. Power is therefore (4.24*4.24)/8 which is 2.2 watts. 8 is the typical speaker impedance. Not a lot is it
In practice it will be even less because the amp won't swing the full 12 volts because of internal losses. Can't advise you on which chip is best for such a low voltage application.
I suspect Class D (which typically uses a bridged output stage) will give the best performance for what you are after. It efficient, and the bridged output means it can swing twice the supply voltage across the load... I'll let you work that one out
there is no best chip.
selecting one depends on what you want to achieve.
for minimum external parts count an acceptible sound quality i would go for tda1557q or one of its relatives that are easy to obtain.
but, if you are a student then you might know that pc-psu is smps.
when it turns on it has a huge voltage spike, that might kill an ic.
so some delayd relay type of powering stuff up properly is needed.
BTL chips get you more power then SE config for a given speaker.
the next thing you can do is choose speakers with 4 ohm nominal impedance.
if you are hunting output power, that is.
then comes some other factors, like bandwidth of the given amplifer.
mostly a wide band is a better choice.
less noise is never bad, so THD figures can help you decide on the chip.
the priority depends on the goal.
selecting one depends on what you want to achieve.
for minimum external parts count an acceptible sound quality i would go for tda1557q or one of its relatives that are easy to obtain.
but, if you are a student then you might know that pc-psu is smps.
when it turns on it has a huge voltage spike, that might kill an ic.
so some delayd relay type of powering stuff up properly is needed.
BTL chips get you more power then SE config for a given speaker.
the next thing you can do is choose speakers with 4 ohm nominal impedance.
if you are hunting output power, that is.
then comes some other factors, like bandwidth of the given amplifer.
mostly a wide band is a better choice.
less noise is never bad, so THD figures can help you decide on the chip.
the priority depends on the goal.
You can get 12W nominal into 8 ohms with 12V using an off the shelf TA2024 amp...
12V 2X15W New TA2024 HiFi Digital Audio Amp Amplifier Board Module | eBay
Which costs so little you can try another manufacturer's if it doesn't work. I have 3 flavors, they all work...
12V 2X15W New TA2024 HiFi Digital Audio Amp Amplifier Board Module | eBay
Which costs so little you can try another manufacturer's if it doesn't work. I have 3 flavors, they all work...
You can run a chipamp (or a discrete amp) from a single polarity supply and it can work very well.
It must be AC coupled at the input and at the NFB leg and at the output.
This is VERY IMPORTANT. An exception is the lm386 which is DESIGNED to run from single polarity without needing AC coupling at the output.
The 12Vdc supply will limit the maximum power that is deliverable. Efficient speaker will be required to achieve reasonable volume.
It must be AC coupled at the input and at the NFB leg and at the output.
This is VERY IMPORTANT. An exception is the lm386 which is DESIGNED to run from single polarity without needing AC coupling at the output.
The 12Vdc supply will limit the maximum power that is deliverable. Efficient speaker will be required to achieve reasonable volume.
Do you actually want to solder parts to a PCB or just assemble a module into an amplifier? If you are happy with a module I recommend this (click the link)
http://www.diyaudio.com/forums/vendors-bazaar/265881-some-more-really-small-amps.html
http://www.diyaudio.com/forums/vendors-bazaar/265881-some-more-really-small-amps.html
As richie00boy mentioned, clarify your goals a bit ....
Start at the output end, what speakers, Ohms and efficiency are most important. Efficiency is dB at 1 meter and 1 watt ( typically ) There are whole forums on this topic here at diyAudio.
Knowing what your speakers do, how loud do you need to go, what distortion can you live with, and what box does it have to fit in. That more or less defines that amp.
Finally look at your source .... does it need a DAC??
I've been playing with these, fun cheap and quite loud even with not very efficient full range drivers in PVC pipe ...
Lunch Money Amp
Don't get paralyzed, with a 12V amp, even if you mess the whole thing up, its just a few pints ...
Start at the output end, what speakers, Ohms and efficiency are most important. Efficiency is dB at 1 meter and 1 watt ( typically ) There are whole forums on this topic here at diyAudio.
Knowing what your speakers do, how loud do you need to go, what distortion can you live with, and what box does it have to fit in. That more or less defines that amp.
Finally look at your source .... does it need a DAC??
I've been playing with these, fun cheap and quite loud even with not very efficient full range drivers in PVC pipe ...
Lunch Money Amp
Don't get paralyzed, with a 12V amp, even if you mess the whole thing up, its just a few pints ...
i assume you need to put amplifier inside pc?if wrong assupmtion sorry but whatever,
you need this:
150W DC DC Boost Converter 10 32V to 12 35V 6A Step Up Voltage Charger Power | eBay
then something like this:
TPA3116 2 1 2 50W 100W Class D Amp Amplifier Completed Board DC 18V 24V | eBay
it works fine on 8 ohms gives around 15-20 watts at 24v ,subwoofer output is trough lpf but stereo output is direct so you can plug sub if you want but dont have to if you dont want
note: in some cases there can be noise from pc components presented on output but only on volume pots on middle position, not sure why.
you can use audio headers from motherboard to plug audio direct,or usb headers to plug soundcard ,all fits inside case,and you can vary boost converter output voltage according to speakers connected and chips datasheet for best possible outcome.
you need this:
150W DC DC Boost Converter 10 32V to 12 35V 6A Step Up Voltage Charger Power | eBay
then something like this:
TPA3116 2 1 2 50W 100W Class D Amp Amplifier Completed Board DC 18V 24V | eBay
it works fine on 8 ohms gives around 15-20 watts at 24v ,subwoofer output is trough lpf but stereo output is direct so you can plug sub if you want but dont have to if you dont want
note: in some cases there can be noise from pc components presented on output but only on volume pots on middle position, not sure why.
you can use audio headers from motherboard to plug audio direct,or usb headers to plug soundcard ,all fits inside case,and you can vary boost converter output voltage according to speakers connected and chips datasheet for best possible outcome.
Attachments
Sorry I took a while to reply!
sreten: I've started to gather that! I've had a browse through eBay and I've looked at reviews of some cheaper amplifiers and seen what chip sets they use (The preferred seems to be TA2020/TA2024)
Arty: I've been looking into the power supply issue, I was aware of it happening, but it had slipped my mind! thanks for reminding me! I belive i have found a power supply that wont and if not i have a regulation circuit we covered last term that should cover me
Thanks for the Amp Recommendation too! I've looked into it and it looks like a good amp but i think i'm leaning more towards a TA2020 as there seems more support for the chip as it's used in so many cheap applications!
counter culture: Thanks for this recommendation! I purchased a TA2020 to listen to the sound quality to see if i would be happy with it, and its very satisfying considering I paid £15 for it!
abraxaltio: Thanks for this recommendation too! A chip that looks good and more capabilities than the others such as a Clipping & Diag pin that would be very helpful. However it would be difficult to get to me.
AndrewT: Are you talking about an chip such as an LM3875? I thought the minimum of most Class D was just under 18V (For the decent chip amps)
richie00boy: sadly i need to make design and solder the amplifier myself, but i commend you design capabilities that looks like an awesome amp!
djonesii: my source of power is an 12V from a PC PSU, I'm not interested in a DAC, I did consider it, however the cost of making one will put the cost up too much (It has to be affordable):/ I'm going to design for a 4 Ohm speaker due to how little power I have
Thats a good looking amp!
tonitonitoni: Sadly its not for inside my computer its part of a bigger system that includes LEDs, and the system draws to much current i need to use a PC power supply
So after all your replies:
On Amazon I purchased this
I was actually amazed by the sound for the cost which will be more than enough for what I need! (I have it hooked up to some 20 year old speakers, a 2A power supply and i'm happy, so if its done properly i'll be happier)
Whilst I appreciate all the suggestions i think i have settled on the TA2020, as i know what it sounds like, its easily obtainable and theres a lot of help out there for it. If I attached a decent tone control and supplied it with a little more current, I think it could work very well!!
Just need good tone control circuit now with my OPA2134s(Free samples...)!
Will
sreten: I've started to gather that! I've had a browse through eBay and I've looked at reviews of some cheaper amplifiers and seen what chip sets they use (The preferred seems to be TA2020/TA2024)
Arty: I've been looking into the power supply issue, I was aware of it happening, but it had slipped my mind! thanks for reminding me! I belive i have found a power supply that wont and if not i have a regulation circuit we covered last term that should cover me
Thanks for the Amp Recommendation too! I've looked into it and it looks like a good amp but i think i'm leaning more towards a TA2020 as there seems more support for the chip as it's used in so many cheap applications!
counter culture: Thanks for this recommendation! I purchased a TA2020 to listen to the sound quality to see if i would be happy with it, and its very satisfying considering I paid £15 for it!
abraxaltio: Thanks for this recommendation too! A chip that looks good and more capabilities than the others such as a Clipping & Diag pin that would be very helpful. However it would be difficult to get to me.
AndrewT: Are you talking about an chip such as an LM3875? I thought the minimum of most Class D was just under 18V (For the decent chip amps)
richie00boy: sadly i need to make design and solder the amplifier myself, but i commend you design capabilities that looks like an awesome amp!
djonesii: my source of power is an 12V from a PC PSU, I'm not interested in a DAC, I did consider it, however the cost of making one will put the cost up too much (It has to be affordable):/ I'm going to design for a 4 Ohm speaker due to how little power I have
Thats a good looking amp!
tonitonitoni: Sadly its not for inside my computer
its part of a bigger system that includes LEDs, and the system draws to much current i need to use a PC power supply So after all your replies:
On Amazon I purchased this
I was actually amazed by the sound for the cost which will be more than enough for what I need! (I have it hooked up to some 20 year old speakers, a 2A power supply and i'm happy, so if its done properly i'll be happier)
Whilst I appreciate all the suggestions i think i have settled on the TA2020, as i know what it sounds like, its easily obtainable and theres a lot of help out there for it. If I attached a decent tone control and supplied it with a little more current, I think it could work very well!!
Just need good tone control circuit now with my OPA2134s(Free samples...)!
Will
the 2020a is not a bad chip at all.
sounds verry decent, despite class-d.
if you use it with a computer you can just download the equaliser apo.
Equalizer APO download | SourceForge.net
it is a system wide eq, so every sound comming from the pc will have this eq applied.
i like it.
the settings are text based flat file, it is far more usefull than an opamp based eq.
you can do quite funky stuff with it
you should use a regulated psu set to bit under 15 volts or so. it should be able to handle approx 5A current.
the transformator should be something like 80-100 VA, if you plan to use 4 ohm rated speakers. witch you should.
sounds verry decent, despite class-d.
if you use it with a computer you can just download the equaliser apo.
Equalizer APO download | SourceForge.net
it is a system wide eq, so every sound comming from the pc will have this eq applied.
i like it.
the settings are text based flat file, it is far more usefull than an opamp based eq.
you can do quite funky stuff with it
you should use a regulated psu set to bit under 15 volts or so. it should be able to handle approx 5A current.
the transformator should be something like 80-100 VA, if you plan to use 4 ohm rated speakers. witch you should.
I have come down to two choices:
STA540
TA2020
(12v on a PC PSU. Laptop input/Phone. 4ohm loads)
STA540- I don't know how this will sound at the 12V mark or how good it is anyway. But its got a simple set up. Theres not many builds that use it apart from the odd kit. They are fairy easy to find
TA2020- I know it sounds good, but it has a fair few components to set it up. I know there's a massive thread on here that covers everything. However the supply of chips is a problem.
I'm using an LM1036 as a tone control. (I don't think I'll be needing a pre-amp?)
I'm leaning towards the STA540 as its simpler and a more versatile, but i don't know how it will sound.
Will
(EDIT: I know i said i settled, but it turns out i'm indecisive... )
STA540
TA2020
(12v on a PC PSU. Laptop input/Phone. 4ohm loads)
STA540- I don't know how this will sound at the 12V mark or how good it is anyway. But its got a simple set up. Theres not many builds that use it apart from the odd kit. They are fairy easy to find
TA2020- I know it sounds good, but it has a fair few components to set it up. I know there's a massive thread on here that covers everything. However the supply of chips is a problem.
I'm using an LM1036 as a tone control. (I don't think I'll be needing a pre-amp?)
I'm leaning towards the STA540 as its simpler and a more versatile, but i don't know how it will sound.
Will
(EDIT: I know i said i settled, but it turns out i'm indecisive... )
Last edited:
STA540 what i would recommend more.
the dual bridge config.
and You do not need a pre-amplifier.
lm1036 i had a few attempts with it, but its just far too noisy.
i would not recommend that chip, nor any other eq ic.
to avoid turn on plops the datasheet solution of sta540 may.. not be the best, but it could still work. if not then 2 resistors, a cap and a transistor can do wounders (slow voltage rise, gives enough time in mute mode till the thing catches up).
the dual bridge config.
and You do not need a pre-amplifier.
lm1036 i had a few attempts with it, but its just far too noisy.
i would not recommend that chip, nor any other eq ic.
to avoid turn on plops the datasheet solution of sta540 may.. not be the best, but it could still work. if not then 2 resistors, a cap and a transistor can do wounders (slow voltage rise, gives enough time in mute mode till the thing catches up).
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.