Well, I may be wrong but if I look at your first picture where the print with the tubes is mounted close to that (mains?)
transformer, I can imagine there is hum.
Yes, it is. After rewiring the ground loop, it is still not work.
So, I decide to tear down the tube part, re-layout again.
Hi Peleus
Compare your heater wiring to all these google images then try again....heater wiring tube amp - Google Search
Please keep that input wire miles away from that mains txformer.
Compare your heater wiring to all these google images then try again....heater wiring tube amp - Google Search
Please keep that input wire miles away from that mains txformer.
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Yes, it is. After rewiring the ground loop, it is still not work.
So, I decide to tear down the tube part, re-layout again.
I do not quite understand what you mean but if you move that printed board away from the transformer what is the result then?
I know that this idea will take some re-wiring of that board but I had a more or less same problem with one of my headphone amplifier designs.
Moving the amplifier part away from the supply circuit did solve that.
The site pl802 gave is a real valuable idea to look at!
Hi guys,
Guess what? I've solved the humming problem! hu....Finally.
I asked the transformer supplier, and he said the transformer unlikely the source of problem. He suggested me try to ground the heater line.
I reminded the suggestion form kissabout2002, but not realized the idea clearly.
After doing some research on the google, I choose this solution, but mod little due to I don't have the pot now.
This is my solution as the below picture showed.
Great, No more hum in the low resistance on-ear headphone.
And More, NO rebuild and major modification again. Thanks God!
And, Thanks you all guys and your suggestions.
Sincerely,
Peleus, Taipei, Taiwan
Guess what? I've solved the humming problem! hu....Finally.
I asked the transformer supplier, and he said the transformer unlikely the source of problem. He suggested me try to ground the heater line.
I reminded the suggestion form kissabout2002, but not realized the idea clearly.
After doing some research on the google, I choose this solution, but mod little due to I don't have the pot now.
An externally hosted image should be here but it was not working when we last tested it.
This is my solution as the below picture showed.
Great, No more hum in the low resistance on-ear headphone.
And More, NO rebuild and major modification again. Thanks God!
And, Thanks you all guys and your suggestions.
Sincerely,
Peleus, Taipei, Taiwan
Attachments
New year, new build,in progress, tone correction preamplifier with 12AX7EH schematic ADAGIO from Dr.Bora Jagodics (R.I.P.) . Second build this year .....
Regards,
Alex
Regards,
Alex
Attachments
I love it, congrats, I like the modern-retro style, looks gorgeous, my motto is "The listening experience start with our eyes", very nice well done
Thanks a bunch! True, I like making things look good and you're spot on with my design goal. I wanted it to look old but new. And of course, using a lot of recycled materials as usual. All the metal parts came from the scrapyard.
Yeah, the sewing machine is not ruined either. I have all the parts in storage so I can put it back together if need be. We have these things all over Finland. Probably the first thing any beginner antique collector gets over here.
Many thanks. I may not be able to contribute much to the electrical design of things, but perhaps the glowy pictures make up for it.
