900W H-class PA Amp with Limiter

[deo]

Not tested.

 

[masood251]

Plz.share me in pdf form.

 

[deo]

Drawin is not on the scale.Size is 303x91mm.In post #3761 its gerber file.
It can be opened with Altium.

 

[vedmitraa]

TD CLASS 1800 MY WORK now corrected

there were some small faults in earlier posted designs, now corrected

 

[deo]

Pcb has arrived.Test soon.

 

[eliasib]

Both PCBS ready😉😉

Hi Andrewlebon; good work... I will be following your advances with that amplifier. I am also building a class H for my brother and I would like to have several choices. Thank you.

 

[vedmitraa]

TD CLASS 1800 MY WORK NOW WITH 6 PAIRS OUTPUT

TD CLASS WITH 6 PAIRS OUTPUT ,70% WORK DONE ,WILL COMPLETE SOON.

 

[khalsa]

very nice work ....excellent

 

[naf]

nice work...

 

[saminnografix]

hi for 140VDC rails of H900 can this auto range VU work? any advice for changes?
Apex Auto Amp VU ~ Rahmat Priono

thank you
sam

 

[NMOS]

TD CLASS WITH 6 PAIRS OUTPUT ,70% WORK DONE ,WILL COMPLETE SOON.

Class TD have 2 Rails 18V and 140V

+/- 18 V - Do you how much max. current is required fpr 18V?

Could be 1A ok ?

 

[deo]

It does not work properly.The oscillation frequency is too low (about 50 kHz) and I tried to raise it up but not successfully.I've changed different values ​​to coils from 5uh to 200-300uh without success.Has anyone done it to show us the conclusions he came to?

 

[apexaudio]

It does not work properly.The oscillation frequency is too low (about 50 kHz) and I tried to raise it up but not successfully.I've changed different values ​​to coils from 5uh to 200-300uh without success.Has anyone done it to show us the conclusions he came to?

It does work properly. TD1800 is subwoofer amplifier.

 

[andrewlebon]

TD1800

Hello Apex audio
greetings i think inductor value 100uh as i have made HD
class sucessfully will come to result on sunday when i test
it
warm regards
Andrew

 

[NMOS]

TD1800 is subwoofer amplifier.

HI Apex

Does it means, I cant use TD1800 for Fullrange / amp cant work Fullrange 20 - 20 khz ?

 

[apexaudio]

HI Apex

Does it means, I cant use TD1800 for Fullrange / amp cant work Fullrange 20 - 20 khz ?

You can use it for fullrange but THD will be high on 20kHz. It is PA not hi-fi amplifier THD is as class D amps about 1%.

 

[sajti]

You can reduce the distortion, if you run Q1-Q4 stage (VAS) directly from +/-140V, istead of the switched voltage. Heatsink for Q3, and Q4 will be necessary, and may change Q1, Q2 to higher voltage transistors.


Sajti

 

[apexaudio]

You can reduce the distortion, if you run Q1-Q4 stage (VAS) directly from +/-140V, istead of the switched voltage. Heatsink for Q3, and Q4 will be necessary, and may change Q1, Q2 to higher voltage transistors.


Sajti

THD on TD1800 is very low up to 25W. If you want over 1000W class TD is compromise.

 

[sajti]

THD on TD1800 is very low up to 25W. If you want over 1000W class TD is compromise.

Yes, sure. But You can improve more with my modification, and it costs nothing practically.

Sajti

 

[NMOS]

You can reduce the distortion, if you run Q1-Q4 stage (VAS) directly from +/-140V, istead of the switched voltage. Heatsink for Q3, and Q4 will be necessary, and may change Q1, Q2 to higher voltage transistors.


Sajti

I think

Q1 and Q2 change with MPSA 92 / MPSA 42 300V TO92 small signal Transistor should work