That was it Alex. It is now working. I'll try to get it hooked up to an amp in a little while so I can give it a listen. Square and sine wave look very good.
Blessings, Terry
Blessings, Terry
Hey guys what you think about this power supply board ? 🙂
you guys think will be ok ?
Regards
Juan
you guys think will be ok ?
Regards
Juan
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Well, this morning while I was waiting for answers I went ahead and etched the dobrivoje layout. I wanted to try it with different transistors and I had a pile of BC456C/556C transistors so I populated this one with those. I haven't tested yet but here are some pics.
Blessings, Terry
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Hi Dobrivoje,
Good catch. Thanks. If you can would you post a silkscreen only. A little late for ironing it on to the top of the board but it would be helpful if someone does another. The show everything shot is nice to see the layout but very busy.
I did test and as expected the left channel didn't work with the transistor inverted. I just came in to try to add part numbers so I could troubleshoot when I saw your post. I don't think this circut like my choice of transistors. It clips ugly and has too much gain. The one I did with the BC550/560 puts out 5vac with a 1.2vac input. This one starts clipping at half volume and has a lot of noise on the output. I think I still need to add some part numbers to the screenprint so I can at least verify that the currents are correct.
I'll get back to you after I've had a chance to do some more testing.
Blessings, Terry
Good catch. Thanks. If you can would you post a silkscreen only. A little late for ironing it on to the top of the board but it would be helpful if someone does another. The show everything shot is nice to see the layout but very busy.
I did test and as expected the left channel didn't work with the transistor inverted. I just came in to try to add part numbers so I could troubleshoot when I saw your post. I don't think this circut like my choice of transistors. It clips ugly and has too much gain. The one I did with the BC550/560 puts out 5vac with a 1.2vac input. This one starts clipping at half volume and has a lot of noise on the output. I think I still need to add some part numbers to the screenprint so I can at least verify that the currents are correct.
I'll get back to you after I've had a chance to do some more testing.
Blessings, Terry
OK I fixed the 2N5551. It plays beautifully. I can't see any difference between the one with the BC550C/BC560C and the one with the BC546C/556C. They both play sine and square waves perfectly. The only thing I'm not sure about is the output. With no load this puts out 12VAC. I hooked it up to an amp and it sounds very, very nice. Dead quiet with the volume off. I guess this is designed to use with an amp that has very low gain because 1/4 turn on the knob and it is about as loud as my amp is with the CD player direct. I'm not so sure that the gain might need to be lowered as it will easily overdrive any of my amps.
I highly recommend it. Either layout seems to work just fine. It is quiet and clean and an easy build.
Thanks Mile, Alex and Miodrag!!!!! Another great project.
Blessings, Terry
I highly recommend it. Either layout seems to work just fine. It is quiet and clean and an easy build.
Thanks Mile, Alex and Miodrag!!!!! Another great project.
Blessings, Terry
new born Apex 🙂 again great sound, and mainly easy to build... Thank you Mile...
Short movie...
https://youtu.be/xw5UrAqwwto
Short movie...
https://youtu.be/xw5UrAqwwto
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I have question about gain.. Is It R8 value, which affects total gain? When I will Increase value from 560R let's say to 1k2? Can someone explain me, how can I find feedback resistor? 🙂 Next question is about maximum PSU voltages, and bias for all apex amp. Is it possible to make some table, because I think its still repeated question.. Thank you...
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BTW: How this fan cooling works in this layout? Did you check the effect with the heatsinks with/without it?
I am asking because it's not directly at the heatsink just moving the air a bit from inside to outside I guess.
I am asking because it's not directly at the heatsink just moving the air a bit from inside to outside I guess.
An externally hosted image should be here but it was not working when we last tested it.
Working on 8 Channel 100W Ultimate Fidelity Amplifier AX-14
https://www.facebook.com/photo.php?...40202079353.1073741827.100005701206102&type=1
There is some hole under the heat sink and fan is blowing outside the chasis
To take out hot air inside the case and its realy help for cooling the amp
Nice work, yes R8 (560R) affect total gain, if you increase value to 1k2 it will reduce gain.
Regards