Thanks for your insight.,
measurements taken on left gives 3.8 for + and -
right gives 6.3 for + and 1. for -
least now i know.
regards
rol
PS what went wrong is that i had the - wire from the power of arduino going to the - of the amp and slipped and hit the + pole of the speaker and that's where the hum started on that side and the pop afterwards when opening and closing the amp.
measurements taken on left gives 3.8 for + and -
right gives 6.3 for + and 1. for -
least now i know.
regards
rol
PS what went wrong is that i had the - wire from the power of arduino going to the - of the amp and slipped and hit the + pole of the speaker and that's where the hum started on that side and the pop afterwards when opening and closing the amp.
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Hope you guys don't mind my many pics...
We have music! Rigged it up to the HP out of a CD player, powered with a large laptop brick and driving some 4ohm test speakers. Sounding really good and behaving itself nicely! So my diy reflow was a success. Now to case it up with good power and connect capable speakers.
Thanks gmarsh for the great board!
BK
We have music! Rigged it up to the HP out of a CD player, powered with a large laptop brick and driving some 4ohm test speakers. Sounding really good and behaving itself nicely! So my diy reflow was a success. Now to case it up with good power and connect capable speakers.
Thanks gmarsh for the great board!
BK
An externally hosted image should be here but it was not working when we last tested it.
The official BOM has blue Epcos B32529 film caps on the audio input, but the full kits I built use white Kemet MMK parts as they didn't have 200 of the Epcos ones in stock when I made the big order.
Both have the same dielectric, same construction, same rated voltage, same 5% tolerance, same stupidly low leakage currrent, same electrical characteristics overall really. I seriously have my doubts they'd make any difference in the sound of the amplifier.
Both have the same dielectric, same construction, same rated voltage, same 5% tolerance, same stupidly low leakage currrent, same electrical characteristics overall really. I seriously have my doubts they'd make any difference in the sound of the amplifier.
I love my JBC! Instant tip heat up, one-hand tip change, great ergos, built like a tank. A real joy to use.
BK
BK
An externally hosted image should be here but it was not working when we last tested it.
Now I understand the question from impuls60. I only know the blue Epcos. If I ever make a change there it'd probably be to transformers.
BK
There's no tracking # that's publically accessible.
The delivery standard is "4 up to 6 weeks" according to the Canada Post site, though that applies to both air and surface transport. If it's not there by the 6 week mark, I can launch a complaint.
Mine arrived today and I concur!
It worked first power up in my quick and dirty "test tray" chassis, but had a but of hum. After reading the posts here I disconnected it all, and ran a jumper to connect signal ground to -ve power and its now running extremely quiet (nothing with ears next to the speaker and music paused).
Using a 50W 20VDC "laptop" style SMPS brick, though a reasonable quality one.
Raspberry Pi with HifiBerry DAC
stepped attenuator volume control "passive" pre.
Econowave waveguide speakers (94dB sensitive)
Chip runs warm to the touch but not hot, this is with no thermal pad, just some space under the board for ventilation.
Thanks for the amazing effort here.
I read the same things you did and I really would like to kill the hum in mine, but for the life of me I have no idea exactly what to do. I do not want to risk damaging my Wiener, so I have not bothered trying to do this.
A close up shot of exactly what you did would be appreciated.
I'm also curious why this would not have been simply included as a PCB trace. I find it odd that the amp hums "by default". Not a slight on you, Gary. I am sure there is a good reason why you chose to do it this way.
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