hum problem with new ts808 clone

[bancika]

I finally finished TS808 clone with keekey mods and tone is great, just there's hum present much more that it should be. Can you point me to some reasons that can lead to this. Sorry, it's my first pedal
Thanx

[burnt fingers]

I think Jack has some good stuff on elimitaing hum on his webzite.

http://www.muzique.com/lab/hum.htm

Scott

[GBlekas]

Jack's site is always a great place to start!  +!


check polarity of electrolytics.

Hum implies a grounding issue.

Regards,
George

www.PedalworX.com

[bancika]

nope, electros are orientated correctly and power supply is 8.9V regulated and filtrated with 100nF caps

[gaussmarkov]

nope, electros are orientated correctly and power supply is 8.9V regulated and filtrated with 100nF caps

100uF? 

[GBlekas]

could you post a pic of the schematic that you used for your project?

Regards,
George

www.PedalworX.com

[bancika]

it's filtrated only with two 100NF caps. that's first suppy I made. now I'm making one with 220uF and 100uF, but it's not done yet.
Template used is tonepad's, and here are some pics. The thing is they are taken before keeley mods with millenium II board that didn't work. Meanwhile I got 3PDT switches and made mods. I don't know if it worked/hummed before it.
Inside view
Board
Solder side
solder job isn't that clean, but hey it's my first pedal
Thanks!

[mojotron]

it's filtrated only with two 100NF caps. that's first suppy I made. ...

Try 100uF caps - that's likely the problem. 100pF are used for higher frequency stuff, 100uF would filter you hum.

[bancika]

I used same supply for marshall jackhammer I have and it was quiet like with battery, so it's probably something else 

[mojotron]

I used same supply for marshall jackhammer I have and it was quiet like with battery, so it's probably something else 

A lot of pedals have their own filter circuits (like the marshall jackhammer - note c20 and c7 are 100uF in the Jackhammer schematic drawn by Surajit) - your ts808 clone from tonepad does not have a full filter circuit it only has a 47uF on the 4.5 voltage. You can do 1 or 2 of the following:

1) Try what I suggested and replace your 100pF caps with 100uF caps in your supply - 100pF will not filter 60 cycle hum very well
2) In your TS808 - put a 100uF cap across the 2 10k resisters that divide the source voltage down to 1/2 the source - filtering the hum to ground - so it does the same thing as your marshall jackhammer.
3) Use another supply or a battery

[bancika]

I didn't make battery clip, so I'll try with new supply which is in the progress..thanks, I'll let you know what happened...