300W @ 4 ohm amplifier module with linear PSU

Wharfedale EVO4.4 Speaker

Kevano

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I am preparing to build an active sealed sub to go with the Marantz NR1510 AVR . Have chosen the 200W 12inch Iwai driver and I'm sorted on the box building details; internal volume, bracing, material etc.

I need help with the electronics. Would anyone be willing to build a 300W @ 4ohms amplifier module with linear PSU for this.

Since crossover, tone controls and delay are taken care of by the AVR the plan is to have a plate amplifier with the amp module/PCB and PSU mounted on the plate using standoffs. Linear PSU is preferable. So a single board with the amplifier circuit and PSU circuit or two separate boards to connect to a toroidal transformer is what I'm thinking. I can source the toroidal transformer and will make the plate. The amp module and PSU is what I need help with. I am ok with either, a chip based class D amplifier or a class AB amplifier or even a class T. Basically any kind with good build quality and which matches the general sound quality of the MARANTZ AVR.

Please DM me if anyone is willing to help.

Best,
Kevin
Andheri, Mumbai
 
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Kevano

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Use IRS2092 board and Meanwell SMPS or some other reputed brand
Most of the IRS2092 boards seems to be of Chinese origin. The build quality doesn't look good and that makes me apprehensive of the components used. Also the IRS2092 needs +/- 65V and the max voltage with SMPS's I've come across that are available in India is +/-48V. So linear PSU will be needed. Also since a linear PSU is most robust compared to an SMPS I would prefer to have a well designed linear PSU.
 

Kevano

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Yes it is a 4 ohm speaker.

I am familiar with a few class D amplifier IC's like the IRS2092,TDA3255, TDA7294 etc and I understand that an amplifier board/module built with these ICs and good components would sound good but I haven't researched MOSFET based amplifiers. So I'm not familiar with the LJM L15.

If this is on par with the generally accepted sound quality of something like the TDA3255 it works for me.
 
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Kevano

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This is a 150W plate amp. My requirement is 300W.

After researching ready made products I found most of them are imported. So the freight, custom duty and vendor margin doesn't make it a value buy. Also I don't need the crossover, EQ, volume controls etc on the plate amp since these parameters can be set on the AVR.

So for my purpose if I get a well designed amplifier module, linear psu and soft start module built with quality components it should take care of my requirement and be good value for money.
 

diyaudio

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Most of the IRS2092 boards seems to be of Chinese origin. The build quality doesn't look good and that makes me apprehensive of the components used. Also the IRS2092 needs +/- 65V and the max voltage with SMPS's I've come across that are available in India is +/-48V. So linear PSU will be needed. Also since a linear PSU is most robust compared to an SMPS I would prefer to have a well designed linear PSU.
China is the defacto manufacturing hub. Most of the brands purchase from there like Dell, Lenovo etc. China sells in a broad range of quality from junk to high quality. Meanwell SMPS has a pot for voltage adjustment which will get you about 52 volts. Check the amp power at that voltage. Also remember, that between 150W and 300w there is only 3dB difference so dont go by absolute numbers. So it might be ok to power IRS2092 with 52 volts. Meanwell has all protection that you ever need built in, they are used in industries in much harsher conditions than home. The trafo is no match. Try shorting meanwell smps and trafo and see where fireworks happen, on a lighter note :)

Class D and switching supplies are suited for higher power and sub duty, its a mature technology and thats the future.
 

greenhorn

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This is a 150W plate amp. My requirement is 300W.

After researching ready made products I found most of them are imported. So the freight, custom duty and vendor margin doesn't make it a value buy. Also I don't need the crossover, EQ, volume controls etc on the plate amp since these parameters can be set on the AVR.

So for my purpose if I get a well designed amplifier module, linear psu and soft start module built with quality components it should take care of my requirement and be good value for money.

In my opinion, a 150W amp goes into a 200W amp sub than a 300W.
If you have a different opinion
It's your money
 

Kevano

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China is the defacto manufacturing hub. Most of the brands purchase from there like Dell, Lenovo etc. China sells in a broad range of quality from junk to high quality. Meanwell SMPS has a pot for voltage adjustment which will get you about 52 volts. Check the amp power at that voltage. Also remember, that between 150W and 300w there is only 3dB difference so dont go by absolute numbers. So it might be ok to power IRS2092 with 52 volts. Meanwell has all protection that you ever need built in, they are used in industries in much harsher conditions than home. The trafo is no match. Try shorting meanwell smps and trafo and see where fireworks happen, on a lighter note :)

Class D and switching supplies are suited for higher power and sub duty, its a mature technology and thats the future.

I agree.

Do you have any leads as to where can I source a high quality Class D amplifier module ? 300W thereabouts @ 4 ohms. I wouldn't mind Class T either. And I'm serious :)

EDIT: How well would the Meanwell SMPS perform mounted in the back of the subwoofer cabinet in a not a very well ventilated space ? For example what would the lifespan of a Meanwell LRS 350-50-48 in such conditions ?
 
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Kevano

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In my opinion, a 150W amp goes into a 200W amp sub than a 300W.
If you have a different opinion
It's your money
I don't need the volume, crossover, phase and eq options on commercially available plate amps since its taken care of in the AVR settings.

An amp module and PSU is what I need for my build. I would like to design the plate myself and have it fabricated at a metal works vendor near my place. This is what I'd like to do.
 
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adas

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Hi Kevano , apologizes been really busy past couple of days , please find attached datasheet as discussed for 300W amp module.

Regards
Aniket Das
 

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