My class D amp

[Tekko]

I did something like this on my latest UcD prototype and despite beeing a bit of a mess on a piece of prototyping board, it so far has the lowest noise floor yet.

http://i.imgur.com/pW980Gx.jpg
http://i.imgur.com/0B48NDu.jpg

 

[paskal9]

1/ Join all the audio ground together.
2/ Join all the power supply grounds together.

Take track from the audio ground to the edge connector where ground comes in.
This now the star ground point.
Take a track from the power supply ground to the same point.

Words explain it better than a picture.

I have used this technique on 4 audio systems now and never had a hum problem.

also it might a good idea to isolate the audio ground (signal ground) to power ground with a small value resistor.

hum (usually) won't be a problem if you work with 2-3 channels but the possibility of humming shoots up with >4 channel in a single case. in my experience at least.

 

[stewin]

also it might a good idea to isolate the audio ground (signal ground) to power ground with a small value resistor.

hum (usually) won't be a problem if you work with 2-3 channels but the possibility of humming shoots up with >4 channel in a single case. in my experience at least.

😕😕i very much agree with you on that point .many amps i have assembled, when i use more than two channels class d i have serious noise issues . untill i change my layout or i remove preamp circuit if i am using one.😕

 

[exflaco]

Two or more chennels Stewin 25khz ferq diference betwen channels ,or exact the same freq oscilattor (external sincro)

 

[stewin]

two channels three or four of identical class d. ucd or non ucd also same challenge with discreet class d

 

[manojtm]

Hi Manoj,
Please give me more details.
You said it is 1000 watts - now is it stereo or mono ? Sorry I didn't read the whole thread.
You have said the voltage is 45V - is that AC or DC. Now you said you reduced it from 75 to 45. I am rewinding a Microwave transformer, so I can do either, just need a ampere rating.
Let me look through the thread for all other information. And I saw you said it sounds great. Compare the type of sound to something I might know - I have lots of vintage pioneer, marantz, yamaha etc etc. I also have listened to a bunch of newer receivers. Yamaha DSP3090 etc etc.
So You could say its like a pioneer sx 880 but has more power. That would be fine.

And how much shipped to USA.

Thanks.
Srinath.

Hi Srinath,

(a) completed working AUD600 Power AMP Board(IR MOSFET with COILCRAFT Filter),AUD600 Power Board,Signal&Clip indicator board,Volume control with limiter and Balanced input jack.(without transformer)(supply rail DC Min. +/-35V max. +/-47V) Price $180 shipping charge extra.

(b) completed working AUD600 Power AMP Board(FDA MOSFET with COILCRAFT Filter),AUD600 Power Board,Signal&Clip indicator board,Volume control with limiter and Balanced input jack.(without transformer)(supply rail DC min +/- 45V max. +/-70V) Price $185 shipping charge extra.

Spec
(a) Power FTC RMS 8R @275W
Power FTC RMS 4R @550W
Power FTC RMS 2R @1000W

(b) Power FTC RMS 8R @600W
Power FTC RMS 4R @1200W
Power FTC RMS 2R @2450W


Regards
MANOJ

 

[ravpreet420]

Today test all version of AUD600
crystal clear sound ,powerful.
all version of AUD600 working.
no issue with 74hc04,
version 3.0 & ver 1.1 working ...

thanx manoj sir
regard

 

[manojtm]

Hi,

Thank you ravpreet

Regards
MANOJ

 

[stewin]

hi all . i modified the smps to use with the aud 900 . i made it to fit 3u space so as to easy mounting. i brought the ic closer to the output fets.

 

[hunter audio]

Hi ,

Great work , could you please drop a mail to dasgupta.s@outlook.com

 

[stewin]

1/ Join all the audio ground together.
2/ Join all the power supply grounds together.

Take track from the audio ground to the edge connector where ground comes in.
This now the star ground point.
Take a track from the power supply ground to the same point.

Words explain it better than a picture.

I have used this technique on 4 audio systems now and never had a hum problem.

thanks nigel i did exactly the above and the amp was silent and i was using smps and class d

 

[stewin]

That will not work, it will blow up in your face because the gate driver is a mile away from the switching fets, even if its only a 20kHz smps, the IR2110 needs to be as close to the fets as physically possible.

hi all . i modified the smps to use with the aud 900 . i made it to fit 3u space so as to easy mounting. i brought the ic closer to the output fets.


>>>>>>>>>>>for more power use igbt as outputs and increase the switching frequency by changing sg3525 rt resistor r14 from 10k to about 4.7k <<<<<<<<

 

[exflaco]

Good job Stewin a boss diyers space share pictures your design and oscilogram please

 

[stewin]

for making the former coiling. instruction you can use the below lay out

 

[Tekko]

Never before have i seen smps transformers with primary and secondary interleaved like that.

 

[stewin]

what way do you suggest ? i used the method for long and works .but please post a more efficient way . i am much interested

also good news diysmps

 

[Tekko]

I just meant i have never seen pri and sec interleaved in any of the smps transformers i've unwound so far.

I suppose there are advantages like lower leakage inductance and such.

 

[stewin]

I just meant i have never seen pri and sec interleaved in any of the smps transformers i've unwound so far.

I suppose there are advantages like lower leakage inductance and such.

also there is another efficient way of coiling which is bi-filiar winding. but the tricky part is to use high quality wires because the primary and secondary are twisted together .

 

[manojtm]

Hi stewin,

Good job. Thank you

Never before have i seen smps transformers with primary and secondary interleaved like that.

I think this the best way for high current application

Regards
MANOJ

 

[manojtm]

Hi Ravpreet420,

This is my @2Year old design using lm311 like AUD1000C. clarity was good,low noise one and good power.

I like AUD600. It is simple and best.

Regards
MANOJ