900W H-class PA Amp with Limiter

[iiee3602]

hi sir apex,
h900 is not suitable for sub. it is okey if i add 10uf in base of driver transistor for deep bass sound?

 

[apexaudio]

thanks for the reply sir,
is this correct for triple darlington?
what is the emmiter resistor bias voltage?

It's correct, set 5-10mV on the emmiter resistors.

 

[apexaudio]

hi sir apex,
h900 is not suitable for sub. it is okey if i add 10uf in base of driver transistor for deep bass sound?

Don't do that.

 

[wattaniya]

hi apex sir , thanks for the reply.
now i include the 10k pot.

if u don't mind, pls check the hole pcb layout and tell me is it correct or anything wrong.

 

[lance06]

hi apex
can i use BYW29-500 for h900?thanks.

 

[Djnits]

On IRF540 is only 55Vdc.

hello sir apex...can i use IRF630 insted of IRF540 thanks

Regads

 

[apexaudio]

hello sir apex...can i use IRF630 insted of IRF540 thanks

Regads

No, use IRF2807 instead IRF540.

 

[buttercup1108]

Use 1k pot (or without pot) with MJE340 for Q5 (Vbe multiplayer bias transistor). 10k pot use with darlington for Q5 (like BD681...) i dont know which post is thats schematics.
Regards

schematic of b500 tef use for reference to h900 tef add limiter as per sir miles this schematic is correct according to sir miles

regards

 

[iiee3602]

Thanks sir apex. What possible way to go to sub?

 

[vedmitraa]

Hello Sir Miles ,
Can we have A full circuit and P.C.B. of Triple Emitter follower
Regards
VedMitraSharma

 

[wattaniya]

hi apex sir,
for the PA , with 4pairs, what is the maximum voltage for 2ohm load? (75vdc-35vdc-0 or 80vdc-40vdc-0), which one u suggest? i need a accurate value for this.

how much power it can deliver into 8ohm,4ohm,2ohm?
what are the transformer VA rating, need for stereo?
I'm expecting Ur reply sir.

 

[44250]

hi sir apex,
h900 is not suitable for sub. it is okey if i add 10uf in base of driver transistor for deep bass sound?

Why h900 isn't suitable for sub? For what it is suitable for?

 

[wattaniya]

hi apex sir,
pls check post 2071.
there are three questions, pls reply to those questions.

 

[apexaudio]

hi apex sir,
for the PA , with 4pairs, what is the maximum voltage for 2ohm load? (75vdc-35vdc-0 or 80vdc-40vdc-0), which one u suggest? i need a accurate value for this.

how much power it can deliver into 8ohm,4ohm,2ohm?
what are the transformer VA rating, need for stereo?
I'm expecting Ur reply sir.

Use 75-35-0-35-75vdc for 900W at 2ohm load.

 

[wattaniya]

Use 75-35-0-35-75vdc for 900W at 2ohm load.

thanks for the reply sir.
what are the transformer VA rating, for stereo?

75-35-0-35-75vdc with this voltage how much power for 4ohm?

 

[apexaudio]

thanks for the reply sir.
what are the transformer VA rating, for stereo?

75-35-0-35-75vdc with this voltage how much power for 4ohm?

2000VA 4x25vac (20A)

 

[wattaniya]

thanks sir.

 

[IRSound]

Hi apex
thanks for H900 design..
can you prepare some table like the ones I attached ? that is for quasi nmos350 + (power rating of transformer and obviously lines current).

also i have another question from H900 performances , how is H900 DC-Offset ? for example in nmos350 we can adjust some variable resistor to minimize DC-Offset.

Regards

 

[apexaudio]

Hi apex
thanks for H900 design..
can you prepare some table like the ones I attached ? that is for quasi nmos350 + (power rating of transformer and obviously lines current).

also i have another question from H900 performances , how is H900 DC-Offset ? for example in nmos350 we can adjust some variable resistor to minimize DC-Offset.

Regards

B500 and H900 use OP amp for DC servo, no need to adjust DC offset.
Regards

 

[iiee3602]

Why h900 isn't suitable for sub? For what it is suitable for?

Not good for sub compare to clone k10.