Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Hoodnight on February 18, 2022, 09:34:11 pm

Title: Snap, crackle, & pop! Location based problems.
Post by: Hoodnight on February 18, 2022, 09:34:11 pm

Hey all. I pulled half of what's left of my hair out troubleshooting my deluxe reverb because of an intermittent crackling issue. Turns out it's actually being caused by (I assume?) the proximity of the amplifier to the mains power connection for the block of units I live in.

I made a quick video - first shot is the problem area, second shot is about 7' away but the same output socket etc.

Aside from the obvious solution (move the bloody thing) are there any steps I could take to remedy this?

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: shooter on February 19, 2022, 03:16:33 am

"crackle", or "frying bacon" are typical for a bad connection.  could be solder, wire, something is "breaking then making".


easy test, while playing, rock the amp back an inch or so and let it "drop back".  did it crackle?
another is the slap test, (better on head units)  just whack the side, back, front.  Did it crackle?

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: Latole on February 19, 2022, 09:23:24 am

Shooter is right

And you may need to replace all tubes's plate resistors, mostly 100k on preamps

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: Hoodnight on February 19, 2022, 09:12:33 pm

Yeah I've opened it up and checked all connections previously. No crackle when I knock it either. The crackle is 100% reproducible by moving the amp that specific side of the room, and always goes away when it's moved to the opposite side.

I can actually even hear the crackle through my headphones plugged in to my audio interface, which is on the same side of the room. It has to be electrical interference, but it's not your usual hum so I'm not sure how to deal with it.

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: PRR on February 19, 2022, 11:07:42 pm

Is that wall really back to back with your whole building's power connection? Everybody's clicks and clacks as they turn lights and ovens on or off?

I'd keep all my audio AWAY from that wall.

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: sluckey on February 20, 2022, 12:56:03 am

Quit pulling hair and just move the amp. Nothing wrong with it.

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: valvetones on February 20, 2022, 01:58:22 am

Get an isolation transformer?

Title: Re: Snap, crackle, & pop! Location based problems.
Post by: Hoodnight on February 20, 2022, 06:48:34 pm

Yeah the power line from the street is hooked right in to that corner. This apartment's pretty tiny, so there aren't many spots I can actually leave the thing without pissing off the girlfriend.

I guess I'll just have to shufflie it over when I'm playing.