Newly developed amp hum

[Eazy-ESP]

Fryette D120. OG - no loop. I have used this amp perched right next to me for years. Never had hum like this. I know transformers hum. But this is excessive.

I was moving stuff around and put the amp on its side and left it sitting like that for a couple of weeks. Only thing I could think of is something is loose from that. I checked tubes and they are all in tight.

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

No new additions to the pedalboard? Is it a mains hum or a loud high pitched sound? That would be a ground loop

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

The first thing i would do is plug straight into the amp, and see if still there. Then plug another guitar into the amp. Then use a different cable between guitar and amp. If these three things don't work, then you need to look at the power. Are you sharing the power with your audio interface?

 

[Eazy-ESP]

The first thing i would do is plug straight into the amp, and see if still there. Then plug another guitar into the amp. Then use a different cable between guitar and amp. If these three things don't work, then you need to look at the power. Are you sharing the power with your audio interface?

Thing is it’s the same power point, same room, etc as always. The sound is without guitar plugged in. Only thing I just thought of is it is a different lead to cabinet.

I’ve been loadbox to DAW for ages now and decided to have a weekend of amps into cab (made me realise how glorious it is and I have been missing it).

I played my Cornford no issues, Marshall 2203 no issues, then plugged in my main amp the D120 and the hum was way more than anything I remember. Actually, the first time I plugged in there was no sound. Something is definitely up. Going to investigate more after dinner.

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

There may be a way to set up an isolator transformer to get rid of this.

I had to use one on my pedalboard for four cable method

 

[2dor]

I had something similar happen recently and it was caused by the shielding in the cable going to the amp's input having been torn due to twisting.

 

[Eazy-ESP]

Weird. So I plugged back into the Rivera RockCrusher with same speaker cable. Noise gone. So I am only getting this hum plugged into my 4x12. I am not very knowledgeable on the technical aspects, wonder if it’s some kind of cabinet/transformer interaction thing.

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

Do you have an actual speaker cable (non shielded)?

 

[Eazy-ESP]

Do you have an actual speaker cable (non shielded)?

Yep. Heavy duty planet waves. I’m going to buy a new one next week. I had the worst luck with planet waves instrument cables, but this speaker cable has been ok. Now I don’t trust it.

 

[2dor]

Maybe spray a bit of contact cleaner in the 4x12 cab & give a little bit of a wiggle with another TS cable? Could just be dirty contacts.

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

Yep. Heavy duty planet waves. I’m going to buy a new one next week. I had the worst luck with planet waves instrument cables, but this speaker cable has been ok. Now I don’t trust it.

I used to use those also. I had them go bad all the time, so i started using mogami. But there are a lot of great cables out there

 

[glpg80]

I don’t think it’s the amp. I think your ground connector on the cab is fucked. Since it works with one load and not the other, If it were the cable, you could move it around to get it to start and stop to try to prove or disprove a bad cable ground.

 

[JTyson]

I’ve had hum induced by power tubes that were old and drifting out of spec and were not matched up tight but it sounds like you’ve already eliminated that..