View Full Version : Smps for D25 amp

06-15-2017, 02:19 PM
good morning.
Do you know D25 digital amplifier?
I want to create a multichannel with D25 amplifier.
It originates from IRAUDAMP7 IRS2092.
It offers 200-250watt rms in 8 ohms, with +/- 60v to +/- 80 volts.
I have created a 4 channel preamplifier, with parallel possibility, or bridge.
I have a large transformer, taken from bheringer ep4000 and modified for 50 volt output,
after rectifier bridge and capacitor it becomes +/- 70volt.
70v was ok for operation, with 80 volt temperature d25 being very high. +/- 70volt is right.
Now i want to build home, for 4ch amplifier, and insert amplifiers, preamplifier and transformer a 1u rack,
but transformer is very big and heavy,
i would like to build smps for 4 pcs d25 but i think i be very powerful and dangerous.
I would like to build 2 smps for 4ch d25 amp, 1smps for 2 channels.
I did research and testing, found that for maximum rms power d25 i need about 4 amps.
Here are some calculations
Vin = 70V
Veff = 64V
Prms = 250W
250w / 64V = 3.9A
In peak power about 8A
You have idea to get smps output +/- 70v about 8Amper continuous and peak 16Amper
with aux output +/- 15v 1 Amp
and turbo fan output 12v 1.5A

06-15-2017, 08:12 PM
Do you intend to add feedback to your SMPS for voltage regulation? So you want an smps 1200 watts continuous and 2000w peak quite a hefty one though. I am not sure but comparing an iron core trafo with an smps I guess the smps does not need to be as powerful as the iron trafo because the capacitor bank will be recharged quicker due to the higher frequency of operation. Well using that power you are saying in your living room will surly crack the glass and move the furniture. LOL

Check this one see if it suits you. There are full schematics available and also pdf containing all details


06-15-2017, 09:43 PM
I do not know smps, that's why ask for it to you. Smps 1000watt effective, to drive two D25 doo with 8ohm load and powered by +/- 70volt, is it right ????? Math calculation be right? This is a project for large room, open garden. I connect 4 200watt rms speakers for each amplifier channel

06-16-2017, 07:19 AM
Hello Pietro, Did you ever build a SMPS? If not do not try to build a high capacity smps as these are not so easy to do like normal iron core transformer. You will be in for a lot of surprises. If you intend to build smps you better start with a small one first until you learn. You need to have an oscilloscope as you will not see what is going on.

1) You will never run your amplifier at full blast its not good as you will be prone for distortion and also PA will not like it.

2) Usually for music the load is more or less 30-60% depending what type of music do you play.

3) Capacitor bank will handle the music peak and power supply is there to fill again the capacitors so the load is not always constant. SMPS can fill capacitor bank more quickly than iron core transformer as pulses are a lot quicker (example 60Khz) compared to 50Hz with iron transformer.

The power supply I built can go for 900watts continuous and 1200watts peak. and need fan cooling for heat sink and transformer.

There is also another tread for 1000 watts smps by Ludo 3232 based on MicrosiM design it may be easier for you to build. it uses a normal heat sink not like mine with a CPU heat sink. There are all the details in the tread.

Regards, Silvio

06-16-2017, 07:37 AM
I have never built large smps, usually use small smps with top261, used, built for small active speakers under 300watts. For this project I should use 4smps with top261, but in this case top261 work limit

06-16-2017, 08:56 AM
Do you have an oscilloscope? it is very important !

This is a very different story and you have to wind a larger transformer. Also the transformer winding is very important and should be made in a way that it have to be safe otherwise it may kill you if you do not take necessary precaution. I suggest that you read the blog post on diysmps.com Transformer winding practices for smps Smps is no joke and care has to be taken at all times especially if they are off line (powered by the grid) you should also read in the forum post Switchching supply informations You can also search on you tube to see how transformers for smps are made.

link https://www.youtube.com/watch?v=_K3ixhcTYFg

regards, Silvio

06-17-2017, 10:59 AM
Ok, now study