Hello Apex,
Yeah I did use red LED, the green one is only for testing.
Test procedures made with red LED/LDR assembly:
1. Resistance when LED is off roughly it's @ 800K - 1M.
2. Resistance when LED is on it's @ 300 Ohms.
I have seen lots of post for the step driver circuit and some have corrections. I wonder what's the correct circuit to use and the proper wiring for the said circuit. Can you post the right ones please?
Thank you once again!
Regards,
Blueice23
When using b500 without step driver what will be psu voltage and power output ? using 4 pairs of o/p devices.
Hi apex,
can i use mjl21193-mjl21194 in place of 2sc5200-2sa1943.
which circuit to use for soft start.
Also i will be using 3 pairs per side. what should be the output.
This is the pcb i will be using for regulated psu 75-0-75, is it fine.
thank You
can i use mjl21193-mjl21194 in place of 2sc5200-2sa1943.
which circuit to use for soft start.
Also i will be using 3 pairs per side. what should be the output.
This is the pcb i will be using for regulated psu 75-0-75, is it fine.
thank You
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![APEXaudio%20B500%20PCBMON[2].JPG](/community/data/attachments/190/190101-f2475b1fe37daec3359168e1e6ebea9a.jpg?hash=8kdbH-N9rs)
I suggest minimum 30mA for 15V zeners. Resistor value R is HV-15/0,03. For +/-80V rail R is about 2k2/2W, if you want 50mA use 5W resistor or two 2W resistors in parallel.
apex,
if 2k2 for 80v,
what v for this 4k7?below80v?
if 2k2 for 80v,
what v for this 4k7?below80v?
Attachments
![APEXaudio%20B500%20PCBMON[2].JPG](/community/data/attachments/191/191462-f2475b1fe37daec3359168e1e6ebea9a.jpg?hash=8kdbH-N9rs)
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Hi, Apex.
I have some minor problems with your B500 amp:
1. When I connect +/-63V, there is about 50mV on output.
2. 400mV on input.
3. Resistor 22ohm is little darken, but no change in resistance.
I had used 2 pairs of output transistors 2SC5200/2SA1943, and MJE15030/15031, 4K7/2W resistors.
ZD12V and TL072 are only changes. And I didn't have 33pF capacitor, so I put 47pF. 😱
Can you help me to locate source of the problem? Please sir.
Regards 🙂
I have some minor problems with your B500 amp:
1. When I connect +/-63V, there is about 50mV on output.
2. 400mV on input.
3. Resistor 22ohm is little darken, but no change in resistance.
I had used 2 pairs of output transistors 2SC5200/2SA1943, and MJE15030/15031, 4K7/2W resistors.
ZD12V and TL072 are only changes. And I didn't have 33pF capacitor, so I put 47pF. 😱
Can you help me to locate source of the problem? Please sir.
Regards 🙂
B500 in the finish line
Hy Apex! Thank you again for this great amplifier, I made tests during the weekend, it worked with 2 15"+1" 300W 2-way speakers, and it ran for 7 hours at the speakers' top volume. The amplifier was only about 30°C, the caps and the transformer performed also very well. The supply voltage was 2x76VDC before use, and after 4 hours of continous use it only dropped 1,5V, and it was smooth, not dropped even at the hardest beat. Now I disassembled it, because the casing will be painted, and then I make pictures of it, and share on this forum.
Thanks, bye!
Hy Apex! Thank you again for this great amplifier, I made tests during the weekend, it worked with 2 15"+1" 300W 2-way speakers, and it ran for 7 hours at the speakers' top volume. The amplifier was only about 30°C, the caps and the transformer performed also very well. The supply voltage was 2x76VDC before use, and after 4 hours of continous use it only dropped 1,5V, and it was smooth, not dropped even at the hardest beat. Now I disassembled it, because the casing will be painted, and then I make pictures of it, and share on this forum.
Thanks, bye!
did u check the amp at the full volume for 7hours in indoor or outdoor with speaker.
Hy! The amp wasn't at full volume (I guess) because the speakers couldn't handle that output. It was indoor, and was really warm (120 people danced on a 200m2 dancefloor)
Bye
how much ampere transformer do u use and the core size, bobbin size.
for stereo one transformer or two?
HELLO APEX SIR
THERE ARE SO MANY NANOFARADS IN B500 SO WHAT IS THE VOLTAGE OF NF? BECAUSE HERE IN SHOPS 50V,60V,100V,250V SO WHICH ONE IS CORRECT?
CAN I USE IN4007 DIODE NSTEAD OF IN4004?
THERE ARE SO MANY NANOFARADS IN B500 SO WHAT IS THE VOLTAGE OF NF? BECAUSE HERE IN SHOPS 50V,60V,100V,250V SO WHICH ONE IS CORRECT?
CAN I USE IN4007 DIODE NSTEAD OF IN4004?
Hello Nazirdigi
I use 1N4007, and amplifiers work fine. You can use it.
1N4004 = 400V 1A
1N4007 = 1000V 1A
Regards
I use 1N4007, and amplifiers work fine. You can use it.
1N4004 = 400V 1A
1N4007 = 1000V 1A
Regards
B500 PA
Dear Apex,
I have a power supply here 20 amperes but the secondary is 70V-0-70V AC.. can i used this power transformer with the B500 power amp?
Dear Apex,
I have a power supply here 20 amperes but the secondary is 70V-0-70V AC.. can i used this power transformer with the B500 power amp?
It was a room with 10 meters x 20 meters (200 square meters) - and full of people 🙂
Well, I bought the transformer. I use 1 transformer, but as I am limited with the space I can use (because of the casing) it is a 1500VA, has 2x55VAC+2x18VAC secondaries. I don't know the exact inner parameters (core, bobbin)
I hope I could help.
Bye
If it is a toroid, you can easily wind down a few turns...and get about 2x55V, as I tested the amp, it was the best for it.
Bye