Chip amp power supply- a beginners guide

R.I.P.
Joined 2004
The backplate of most chipamps is connected to one polarity of the power supply.

If a chipamp is mounted direct to the heatsink, then that heatsink is directly connected to the power supply !
 
Member
Joined 2013
Suppose I have a Amp of eg: tda2030
if, power supply for the single channel Tda2030 will be around 12v 3A.
if i increase no. of Channels, lets be 3 Channels. Then what will be the value for PSU.
I heard some where, that its the Current needed to increase ie, 3Ax3= 9A.
Which says PSU will be of 12v 9A. I dont know its right or wrong, but i think its wired.

Hope you Answer.
 
Member
Joined 2006
It is not weird.
If you connect 3 light bulbs parallel, then you still use them from 230V, but the current they need is 3 times.
Same with the amp.
 
Member
Joined 2016
I'm a newcomer myself. The knowledge that all are prepared to share is fantastic and I'm very greatly. However, the notion of what you've put together here for dummies is superb. It would be great to have similar platforms for other areas of builds. Thanks to all who contributed.
 
Banned
Joined 2016
lm3886psu

Finally find probably one godd schematic for regulated power supply that will fit my trafo 32-0-32v / 5A to use for LM 3886 amps.

The transistors will be MJ2955/2N3055.

Any suggestion?


hello, is this psu working ok for you ?
how many amps u can get out of that?
thanks a lot
 
Banned
Joined 2014
Finally find probably one godd schematic for regulated power supply that will fit my trafo 32-0-32v / 5A to use for LM 3886 amps.

The transistors will be MJ2955/2N3055.

Any suggestion?

i am curious about that schematic too, is it a good design ?
thanks
 
Member
Joined 2014
I have transformer with output 20V and 15V AC 60Wats. It is from stereo amplifier that uses tda2030a per channel. Do you think that this is suitable as power source for mono amplifier with LM3886 on 8ohm speaker? Also do anyone knows why transformer is 20 and 15 volts? Usually tranformer is 2x20 or 2x15. Probably there is a reason for this since this is from Japanese working amplifier.
 
R.I.P.
Joined 2004
Can you see if the wire diameter in each winding is the same?
A small diameter on one winding would indicate a lower current rating and intended for powering control circuits and auxiliaries.
 
Member
Joined 2014
I cannot check wire diameter because it is not accessible but I will check if both goes into IC. Will give update on this.
 
R.I.P.
Joined 2004
Are you able to measure the resistance of the two windings.
The low power winding may have a higher resistance. But both will be low and difficult to measure accurately.

Can you pass a known DC current through the two windings?
 
Member
Joined 2009
This is the board I purchased.

Yuan-Jing TA2022 2 x 180W Audio Power Amplifier Board


It says to use two windings 22-0-22 transformer but I will use one winding 20V transformer for each channel (dual transformers). Reason for being *20V is not to exceed the ideal 30V operating voltage. Each transformer will be 250VA. I was going to do 300VA each but read not to use 300VA unless I do soft start and use two on/off switches (one for each channel). 250VA for each channel should be plenty I think.

I may sound like I know what is what :) but this is all from reading and talking to people. I am definitely a beginner!

Am I on the right track?


* 20V x 1.414 - 0.7V (rectifier diode) + 10% (load)= 30V

22V gives me more than 30V which is not recommended when TA2022 is BTLed.

Don't know why they say to use a 22V transformer?
 
Member
Joined 2006
The Tripath datasheet says the following :-

Power Supplies
The TA2022 requires the split supply rails.

The TA2022 can operate over a wide range of power supply voltages from +/-12V to +/-36V.

As I understand it Tripath went under many years ago. Whether there are still any NOS chips around I don't know. The board you have bought may have cloned chips on it.

The Yuan-Jing board connections for the power supply could confuse some into thinking that they need 2 transformers. The board requires a centre tapped transformer (3 wires) and only the centre tap (one wire) will go to grd. If you look at the customer photo gallery on the link you sent you will see that the transformer used there has only 3 wires and only one grd pcb connector has been used.
 
Member
Joined 2009
I had no idea they were cloning Tripath. I know they are long gone but I have heard there are still NOS available.

No, I meant I want to use two transformers. I think dual transformer will make a difference. At least it does make a difference in my TP60 TA2022 amp or I think dual transformers are the reason for separation of the instruments like I have never heard before from any amp.
 
Last edited:
Member
Joined 2006
If you want to use two transformers then I think you would have to modify the board. There are two bridge rectifiers and (without having seen a schematic) I would suspect that they are linked and to use two transformers would mean that you would have to cut some tracks.

Are Tripath chips sill being manufactured?
 
Last edited:
Member
Joined 2009
You threw me off there!:)

Why would using one transformer with two secondary windings would be different than using two dual transformers each having one secondary winding?
 
Member
Joined 2006
I think you need to read some stuff about single power supplies and split rail supplies and then apply this to the board you have.
 
Member
Joined 2018
I finally finished selecting components at mouser for my dual mono 20W amplifier: Cornell Dubilier PP-capacitors, Nichicon KZ EL-capacitors & 2 toroidal's 50VA. I think I can finally start designing 2 powersupplies (same design) that fits my dual mono amplifierbuild perfectly.

1. My first question is which circuitdesign is most optimal for a dual mono lm3886tf amplifier and why;
2. My second question is how I can calculate all the components and capacitors and how many capacitors are most optimal for my my dual mono amplifier? After reading on your website that 10.000uF capacitors can flatten midbass and other stuff like that, I assumed this small sentence was important regarding soundquality. I want an efficient/optimal powersupply design, does anyone here have a link or information, that helps me to determine which powersupply-design is best for a standard mono lm3886 amplifier & how many capacitors and which sizes are most optimal?

For anyone reading and/or helping me get started on designing my psu's, thanks!
 
Member
Joined 2018
I can not edit my post so this is part 2 of my post so I can explain why I am confused:

circuitsbasics 20w*2 lm3886tf amplifier guide
: Stereo amplifier, 250VA toroidal i.c.w. 8200 uF*4 capacitors (they do not explain why they pick 8200uF)
neurochrome power86 : 3300uF * 2 (if i remember correctly).
neurochrome toroidal calculation : 100VA (instead of 250VA by circuitbasics)

The designmethod-difference and outcome is quite huge, I believe this could be under in the influence of using the crestfactor-method (or not). Hopefully I can even go lower capicitance then the power-86, because i will have only 1 channel per psu.

Normally I can find similar methods on the internet, but now i have carlosfm-psu on decdun-blog with 2x10.000 uF and I do not know why. I have a circuitbasics which has 4x8200uF and I can not seem to find why they use that capicitance. And neurochrome only has 2x3300uF (iirc) and I can not find out why without buying the psu.


Hopefully you guys and girls understand that I find this confusingand am looking for guidance.
 
Member
Joined 2018
Challenge solved, I found general information about how large the capacitance-reservoir should be on instructables. Now I understand why more reservoir should always be better (more capacitance means a smaller ripple). Still, diy audio is quite challenging if you are not electronically gifted or schooled, but I will get there.


My apologies for littering my incompetence in this topic.
 
Top