Totski, please do not post in all caps, next time i am going to delete your post...posting in all caps is like shouting...it is rude.....
sorry sir, now i understand i didnt mean it. i thought it doesn't matter posting in caps.now i know, sorry again sir.
Use BD139/140 as drivers and without changes you have 35W/8R or 60W/4R (+/-30V rail)
Regards
disconnect the PSU from the transformer.
Power up the transformer alone through a bulb tester.
Power down.
Connect the PSU only to the transformer.
Power up via the bulb tester.
Power down.
discharge the capacitors with a resistor.
Attach one channel of the amplifier.
power up via the bulb tester.
power down
attach the next channel of amplifier.
power up via the bulb tester.
get the message !
Power up the transformer alone through a bulb tester.
Power down.
Connect the PSU only to the transformer.
Power up via the bulb tester.
Power down.
discharge the capacitors with a resistor.
Attach one channel of the amplifier.
power up via the bulb tester.
power down
attach the next channel of amplifier.
power up via the bulb tester.
get the message !
Hello every one..
sorry for the late update..
At last, the Toroid had arrived. and I had a chance to test it today....
traffo specs..
Secondary: 60-30-0-30-60 @20amp , 18-0-18 @1amp
I am using +/-60v for main board and will use +/-30v later for step driver.
connecting to the psu, I get 59v Ac and from psu 82v Dc.
for first power on, I have used 100watt bulb for soft start.
Now I am using protection circuit with relay
I have used led and 47k resistor instead of nsl32.
the protection circuit also works well.
powering on the amp was a great excitement..
Well, I had successfully powered on the 1st channel after double checking my work.
I did some measurements. across 15v zener diodes it's approx13.8v
I have used 4.7k 5W @R24;R25
I get DC offset of 55mv on output.
After a few minutes, assuming the amp is in condition, I connected the speaker to the amp. It was quiet..
using my pc (realtek hd audio) for audio input, I slowly turned on the volume.. And its great I got nice music from the speakers, till the full volume of my pc. I don't have a preamp at present for more volume and controls.
I tested the amp at 30%volume of my pc for two hours. the output was clear and flawless.
The heat sink was cold till half an hour and a little warm later.
I am happy with the first test..
I will build apex ml3 preamp tomorrow...and test the amp to it's full power..
I have used cheap quality 2*12"PA speaker for the test @ 4ohms load.
I have built the amp as stated on post#1
Thanks Mile sir, for such a nice sounding amp..
Thanks Andrew T. for quick guide..
sorry for the late update..
At last, the Toroid had arrived. and I had a chance to test it today....
traffo specs..
Secondary: 60-30-0-30-60 @20amp , 18-0-18 @1amp
I am using +/-60v for main board and will use +/-30v later for step driver.
connecting to the psu, I get 59v Ac and from psu 82v Dc.
for first power on, I have used 100watt bulb for soft start.
Now I am using protection circuit with relay
I have used led and 47k resistor instead of nsl32.
the protection circuit also works well.
powering on the amp was a great excitement..
Well, I had successfully powered on the 1st channel after double checking my work.
I did some measurements. across 15v zener diodes it's approx13.8v
I have used 4.7k 5W @R24;R25
I get DC offset of 55mv on output.
After a few minutes, assuming the amp is in condition, I connected the speaker to the amp. It was quiet..
using my pc (realtek hd audio) for audio input, I slowly turned on the volume.. And its great I got nice music from the speakers, till the full volume of my pc. I don't have a preamp at present for more volume and controls.
I tested the amp at 30%volume of my pc for two hours. the output was clear and flawless.
The heat sink was cold till half an hour and a little warm later.
I am happy with the first test..
I will build apex ml3 preamp tomorrow...and test the amp to it's full power..
I have used cheap quality 2*12"PA speaker for the test @ 4ohms load.
I have built the amp as stated on post#1
Thanks Mile sir, for such a nice sounding amp..
Thanks Andrew T. for quick guide..
