900W H-class PA Amp with Limiter

[crazymechanic]

Hi , could someone please help I finished one channel of h900 and iot went great but on the other one i have no bias voltage on both the PNP and NPN side of the output transistors.It shows aproximetly 0v I guess it should be something like 0.52 volts on the bases on the output trannies.

If someone of you could point me in the right direction.
Thanks

[AndrewT]

what voltage is across the driver?
what voltage is across the Vbe multiplier?

[crazymechanic]

Hi again, well yesterday I got my readings wrong.The first channel do have 0.52v bias on output transistor bases, both sides.
The other channel shows like 0.2 volts on PNP and 0.18 v or something like that on the NPN side of the output transistors.Is this ok? should it be good or should I check something for being wrong?
Also do this amplifier has the signal ground and PSU ground tied together or are they seperate?
because all standart amplifiers have the signal and psu grounds together, I assume this should do the same but I cannot see it anywhere in the schematics shown.

Thank you for helping,
regards, Gīrts.

[AndrewT]

Originally Posted by AndrewT

what voltage is across the driver?
what voltage is across the Vbe multiplier?

Originally Posted by crazymechanic

............... or should I check something for being wrong?..................

[crazymechanic]

on the first channel the voltage across multiplier is 1.8 v on the second which is the faulty one the voltage there is like 0.9v over the mje 340.
what do you mean by the driver? I guess a transistor but which one?

Also , a stupid question but do I wire the signal ground to the powersupply ground in this amp or not, I'm a bit confused as usually signal gnd is wired to psu gnd.

[nazirdigi]

hi apex sir,
can u tell me, what is the bias voltage across emitter resistor for h900 tef with 8pair,
if i put bias preset , what is the value preset should i use?

[iiee3602]

Hello sir apex,
Can i use SR1060c instead of MUR1620c. thanks!

[teslar]

Originally Posted by andrewlebon

to be tested with mjls hope it turns out good

Hi andrewlebon.
Please show EEEengine project.
Regards.

[jhongodpeavey]

Originally Posted by apexaudio

I suggest you to add DC protect with triac after fuse.

SIR can you give me please the dc protect with triac please..

[jhongodpeavey]

Originally Posted by Tube Pro

Hi wg_ski,

thanks for the great insights.
by the way, will Nelson's B1 FET buffer match this h900 amp?
how about impedance matching?

but toroid has great efficiency less powerloss than ei am i right sir..