The ongoing hum issue...

[clipman3]

So I built/designed a tube clean preamp with simple vol/tone/vol controls, and it works great. A little touchy on the tone (need to get linear pots...) but other than that the only issue is the ridiculous hum... It's definately power supply hum. It's constant, and doesnt fluxuate at all except for volume when i adjust the controls, plus it stopped when I attached a 9v planet waves adapter (i dont wanna go with that... so farty).
Should be a simple fix... But I can't seem to get it. I have a 470uF cap and a 100uF cap in parallel right now, and that didnt do anything. I think part of the problem might be that I'm using a 12v 1.5A adapter, but the load is ~300mA, which jumps the voltage up to about 17.5v... Im not really totally sure, I've never had any issues like this  I can upload the schematic if that helps
Thanks to anyone who can help

[chromesphere]

Hey Clipman, i uploaded a video on this topic recently.  Might be useful to you, might not...?  Anyway, check it out:

Hope it helps!  (theres a video on my filter as well if you want something more specific about that filter)

Paul

[clipman3]

Hey Clipman, i uploaded a video on this topic recently.  Might be useful to you, might not...?  Anyway, check it out:

Hope it helps!  (theres a video on my filter as well if you want something more specific about that filter)

Paul

I actually watched your videos! Great job with them, they really helped me to understand the noise a bit more, but the circuit didn't do anything :/
I dunno maybe its not the power source after all

[chromesphere]

Thanks for the compliment!
If the power caps don't work the noise is probably coming from somewhere else.  If your using an opamp (like the LM386  ) try placing the filter caps close to the IC as you can...like....RIGHT ON TOP OF IT.  I found that helped with my dead easy dirt.  Charge pumps make noise as well.  Some circuits are just noisy too unfortunately.
Paul

[clipman3]

Thanks for the compliment!
If the power caps don't work the noise is probably coming from somewhere else.  If your using an opamp (like the LM386  ) try placing the filter caps close to the IC as you can...like....RIGHT ON TOP OF IT.  I found that helped with my dead easy dirt.  Charge pumps make noise as well.  Some circuits are just noisy too unfortunately.
Paul

Its a super simple tube circuit. I'll try some shielded cable and a new adapter... And if that doesnt work Ill juts get a noise filter. Thanks for your help!