500W PA amplifier with Limiter

[apexaudio]

Originally Posted by nazirdigi

urgent
for two pairs of output how many dc voltage required?
and what are the changes.

Use +/-55V rail and 1K5/2W instead 2k2/2W for R24 and R25.

[nazirdigi]

for my opinion clipping means regulates the input signal from the amp am i correct?
if wrong pls explain.

[nazirdigi]

Originally Posted by apexaudio

Use +/-55V rail and 1K5/2W instead 2k2/2W for R24 and R25.

is it 50v dc ok for two outputs. any changes.

[nazirdigi]

Originally Posted by apexaudio

Use +/-55V rail and 1K5/2W instead 2k2/2W for R24 and R25.

is this correct?

[apexaudio]

Originally Posted by nazirdigi

is this correct?

Yes, just 22k from overcurrent detect connect to used 0.33R/5W, +/-50V no changes for single pair.

[nazirdigi]

Originally Posted by apexaudio

Yes, just 22k from overcurrent detect connect to used 0.33R/5W, +/-50V no changes for single pair.

for two pair 50v dc is it ok? any changes.

[yohnsee]

Originally Posted by apexaudio

Measure voltage across Z1, Z2, R20, R21. Try to use mached 2N5401/5551 and MJE340/350.

Hello! I checked the voltages, the L and R indicates wich panel I am talking about. The R is the one with the high DC offset, the L was good so far.

L Z1: 14,2V
L Z2: 14,4V
L R20: 446mV
L R21: 440mV

R Z1: 14,7V
R Z2: 14,3V
R R20: 444mV
R R21: 438mV

I used matched transistors (from the same series, and they were chosen from 15's batch with multimeter's HFE) and i used the closest possible values.

When i connect signal gnd to power gnd every reading is just fine (7-8mV offset on both panels) the 300mV offset only occours when the input pins left floating or the signal gnd is not connected to power gnd.
If it is a solution, to connect them together, then it will stay in this state.

[apexaudio]

Originally Posted by yohnsee

Hello! I checked the voltages, the L and R indicates wich panel I am talking about. The R is the one with the high DC offset, the L was good so far.

L Z1: 14,2V
L Z2: 14,4V
L R20: 446mV
L R21: 440mV

R Z1: 14,7V
R Z2: 14,3V
R R20: 444mV
R R21: 438mV

I used matched transistors (from the same series, and they were chosen from 15's batch with multimeter's HFE) and i used the closest possible values.

When i connect signal gnd to power gnd every reading is just fine (7-8mV offset on both panels) the 300mV offset only occours when the input pins left floating or the signal gnd is not connected to power gnd.
If it is a solution, to connect them together, then it will stay in this state.

Voltages are OK. Use this GND wireing if there is not hum and noise.

[daveinsingapore]

Originally Posted by apexaudio

I cosidering to add signal led, fan control, VI limiter, triple darlington...

Hi Miles....you mentioned that you were going to add these three things, are you redesigning the B500 pcb....I have added the indicator leds to my personal version of the pcb, but would like to see what your design comes out like...it is getting a bit too much for me to modify now, but I do like the XLR input stage you added a few days ago, it makes a lot of sense and actually saved me another board that had a preamp on it...less is better..still waiting to see how you will redesign the B500 to become a BX500.....

[yohnsee]

Originally Posted by apexaudio

Voltages are OK. Use this GND wireing if there is not hum and noise.

Thank you, i was just worried, but if you say it is ok, than i will make it this way.
Soon i will post pictures of the complete amp.