My class D amp

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#61
AUD600

Vostro said:
Hi Pravpa, do you mind posting the artworks for AUD600,
Im also going to make this Amp, but finding all the details isnt made easy.

Thanks
Click to expand...

Hello Vostro,
Here is the entire file of AUD600.

Regards,
Pravpa
 

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#62
Thanks Manoj ,

but why ? because I checked the value of filter with accurate LCR meter..it was about 70uH.
what should i do then ?
what you think about EER cores with 1~1.5mm air gap ?
and my last question...what is your recommendation for output filter @ 250KHz ?

Regards,
IRSound
 
#64
Thanks

i found 2 stacked CK270060 from CSC in my magnetic component box. i will give it a try.
also i have CS270125 and CS330125.

how about the capacitor ? 470nF should be enough ?
this capacitor can effect the mosfet temp or not ?

Thanks Manoj for helping me in this way

Regards
 
#69
IRSound said:
Thanks Manoj ,

but why ? because I checked the value of filter with accurate LCR meter..it was about 70uH.
what should i do then ?
what you think about EER cores with 1~1.5mm air gap ?
and my last question...what is your recommendation for output filter @ 250KHz ?

Regards,
IRSound
Click to expand...

with aud600 ir900 and ir4k5 with my experience is 20turns of etd 38 which is about 18uh and output fets are cool but with 70uh all the above amplifiers : the outputs heat even at low volume with an 8ohm load
 
#70
Hi Stewin ,

as I know , choosing the right value for inductor depends on your load.
for example if we want to connect 8 ohm loads to amp (C=470nF) , you will need a 120uH inductor. also for 4 ohm the value is about 30uH.
we can select middle of those value : 120+30/2 = 75uH ~ 70uH.
with 70uH , the best load should be around 6 Ohm. but i don't know what is the effect with other loads.

Regards,
IRSound
 
#76
IMO, it just needs to start rolling off ABOVE 20kHz and be down around -40dB at fSW. Obviously you don't want any (or minimal) peaking at or below 20kHz.

Playing around with that calculator you will see it's difficult to get a filter that works ok with both 4R and 8R loads. You either end up with excessive peaking or roll-off at the cut-off frequency.
 
#77
manojtm said:
Hi IR,
use T106-2 with 59 Turns 0.8mm wire

Regards
MANOJ
Click to expand...

Hi Manoj!

does this applies to AUD600?

You have mentioned T106-2 iron powder, I have them and I wanted them to be of use on AUD600, but before that....a few question here..🙂

Can I power this amp using a lowly -/+35vdc? Was there a needed adjustment on the circuit?
Can I also use an external 12vdc bias circuit? (not the one on your psu board)
Please guide.

Regards!
 
#78
Playing around with that calculator you will see it's difficult to get a filter that works ok with both 4R and 8R loads. You either end up with excessive peaking or roll-off at the cut-off frequency.
Click to expand...

Yes, you're right.
i found inductor should be around 38uH for C=470nF and R4~8Ohm. but with lower and higher impedance you will have a bad step response.

i have another question , is the DC resistance of inductor is important in Class-D LPF ? because with lower AL value cores (like micrometals -2 series) you will have higher number of turns and lower number of turns for higher AL value cores.

Regards
 
#79
.ups just did my research..I found 2 pdf version, the other with the trimmer for frequency adjust.

Filter : T106-2 0.8mm wire @59Turns(@47uH). Is this connected by joining the tracks for 470nf & 1uf ?

Thanks!
 

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