Strange Hum on Sustainor

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dreamevil
Posts: 22
Joined: Mon Nov 16, 2015 7:11 pm

Strange Hum on Sustainor

Post by dreamevil » Sun Apr 30, 2017 1:11 pm

Hi.My sustainor has a strange hum problem that i couldn't figure out how to fix it. It makes it more when i use dist. (but it happens when its on clean too) When i first bought it, i replaced every elec caps and controlled every solders, cleaned the pcb etc.
I uploaded a video to show you how. After that strange noise came out i opened it again and found that when i touch that component(red circle on the photo) it happens.
Need your help!
Thanks.

VIDEO LINK
https://streamable.com/1luer
You do not have the required permissions to view the files attached to this post.

Fireful0
Posts: 183
Joined: Sat Feb 18, 2017 6:00 pm

Re: Strange Hum on Sustainor

Post by Fireful0 » Thu May 04, 2017 5:46 pm

Sounds like maybe the red component thing you circled is coming unsoldered?

dreamevil
Posts: 22
Joined: Mon Nov 16, 2015 7:11 pm

Re: Strange Hum on Sustainor

Post by dreamevil » Sun May 07, 2017 9:16 pm

Thanks for the hint. I checked it, and solder looked ok. I don't know how and if it was broken.

Fireful0
Posts: 183
Joined: Sat Feb 18, 2017 6:00 pm

Re: Strange Hum on Sustainor

Post by Fireful0 » Mon May 08, 2017 2:11 am

Hmmm...
I wish I knew. :(

GuitarBuilder
Posts: 196
Joined: Sat Aug 30, 2014 7:14 pm

Re: Strange Hum on Sustainor

Post by GuitarBuilder » Tue May 09, 2017 4:04 am

What is the component number? I might find it on the schematic for you.

dreamevil
Posts: 22
Joined: Mon Nov 16, 2015 7:11 pm

Re: Strange Hum on Sustainor

Post by dreamevil » Sun May 14, 2017 11:58 am

I just know the model 2N4338 but which one still don't. Q1,Q2 or Q7...

GuitarBuilder
Posts: 196
Joined: Sat Aug 30, 2014 7:14 pm

Re: Strange Hum on Sustainor

Post by GuitarBuilder » Mon May 15, 2017 1:59 pm

Looks like Q1. Are you sure it's a 2N4338, not 2N4339?

GuitarBuilder
Posts: 196
Joined: Sat Aug 30, 2014 7:14 pm

Re: Strange Hum on Sustainor

Post by GuitarBuilder » Mon May 15, 2017 2:00 pm

Also, did the hum exist before you replaced the caps?

dreamevil
Posts: 22
Joined: Mon Nov 16, 2015 7:11 pm

Re: Strange Hum on Sustainor

Post by dreamevil » Wed May 17, 2017 4:44 pm

There has been always a noise in my sustainor but this is different. When i touched that 2N4338 directly(when its pcb open) or even hit from upside of the sustainor box, hum occures.

dreamevil
Posts: 22
Joined: Mon Nov 16, 2015 7:11 pm

Re: Strange Hum on Sustainor

Post by dreamevil » Thu May 18, 2017 4:01 pm

Thank you so much. I'll try these steps as soon as possible. But on the other hand, i'm trying to find a 2N4338 Jfet replacement anyway.