500W PA amplifier with Limiter

[Kay Pirinha]

In my opinion you should use this.

Regards

Is there any schematics for this protection (?) board?

Best regards!

 

[kandimba]

I would like to help you, but I don`t have it. I only have the electronic diagram, you have to do it, it`s easy.

Regards

please kandimba attach the pcb files of the apex led light display for the front pannel

 

[kandimba]

Is there any schematics for this protection (?) board?

Best regards!

I only have the pcb, but schematic are there.

Regards

 

[saminnografix]

B500P

In my opinion you should use this.

Regards

yes sir but 500P has a balance input while i use ml3 in my tone control,
usually line and mic inputs/outputs we use here are unbalance,
any changes to make?

thanks
regards

 

[apexaudio]

yes sir but 500P has a balance input while i use ml3 in my tone control,
usually line and mic inputs/outputs we use here are unbalance,
any changes to make?

thanks
regards

You can convert balanced input to unbalanced... just connect - input to gnd.

 

[saminnografix]

thanks sir
more power
regardz

 

[rohin]

hi everyone i need input signal pcb for b 500 with singal tone like pro amp please help me.

 

[kandimba]

please kandimba attach the pcb files of the apex led light display for the front pannel

Hi Stewin, dont be sad because I did something for you . I hope that wil be useful.

Regards

 

[kandimba]

Hi Stewin, dont be sad because I did something for you . I hope that wil be useful.

Regards

You should teste it, because is not tested.

Regards

 

[saminnografix]

ML1, MX1, PSU

hi sir APEX sir and others
im planning to have a little mixer using
ML3
MX1
and this PSU i have changed the zener into 15V is this posible?
these are the only components i able to purchase.
i suppose to do the A Class PSU but not all devices are available esp BF245/2sk246 even the 1uf MKT/MYLAR caps, only electrolytic are available so i tried this layout but need your advice..

currently i am using ML3 on my AMPs with 7815 & 7915 still excellent performance than my tone from esp and sam.

i am not an electronics guy just a hobbyst
please help me out
thank you..
regards...

 

[filthyone]

you still don't get the point.
I advocate protection.
I suggest the Triac shorting circuit be moved from output to supply rails.

I am not telling anyone to remove protection. That is completely against my philosophy.

I stumbled across this old post, which i find very interesting as an idea. Why blow the heck out of an output stage, when you can stop the failure in front of it in a safer way?

My question is, how would this be utilized? Two triacs, each across the + and - rail and ground, fired by the same diac? Or maybe one triac across the full rails? Any ideas?

 

[Kay Pirinha]

There's no need for a TRIAC as a cross bar at the rails. Use a (one for both rails!) beefy SCR instead and trigger it the usual way.

Best regards!

 

[stewin]

Hi Stewin, dont be sad because I did something for you . I hope that wil be useful.

Regards

thanks kandimba . here is my version also smd version and dip version

 

[c08bm]

What if we use one triac (or thyristor,mosfet whatever) from + to - rail, -rail go short, there's 50/50 chance that - fuse will blow. If bad luck strikes and + rail blow, there is still dc from - rail. Is it?

 

[filthyone]

What if we use one triac (or thyristor,mosfet whatever) from + to - rail, -rail go short, there's 50/50 chance that - fuse will blow. If bad luck strikes and + rail blow, there is still dc from - rail. Is it?

So i guess that each rail should be treated separetely, each fitted with its own triac to ground. Should be safer that way, as both triacs will be driven by the same diac and so in a case of a fault, both rail fuses will die at the same time.

 

[Kay Pirinha]

... as both triacs will be driven by the same diac ...

Does this really work?

As said before, I'd use SCRs that don't need to be triggered by a DIAC.

Best regards!

 

[filthyone]

An externally hosted image should be here but it was not working when we last tested it.

Does this really work?

I really hope so!
Maybe C1 should be a little bigger, like 2.2μF and of course R1 a little lower, like 150k.
I insist on triacs because they are a lot cheaper than a proper SCR!

 

[Kay Pirinha]

I thought you'd need one DIAC per device?

Best regards!

 

[filthyone]

I thought you'd need one DIAC per device?

Yea, that should be the proper way. Problem is that DIACs are very inacutate devices, as their breakdown voltage ranges from 28 to 36 volts! So i fear that two discrete DIACs might not fire simultaneously, should they ever hear the call of duty! But i might be wrong! Probably i am

 

[sajti]

What if we use one triac (or thyristor,mosfet whatever) from + to - rail, -rail go short, there's 50/50 chance that - fuse will blow. If bad luck strikes and + rail blow, there is still dc from - rail. Is it?

Just check out the Mackie M1400 schematic! The first version use thyristors as crowbar in the power supply. Thyristors are very rugged, and they are specified for fuse blowing.

Sajti