Problem: Triple Rec transformer hum

[Motorgear]

Would appreciate any help with this guys.

Recently my Triple Rec started a low hum right above and behind the On/Off Standby switches, where the transformer is located in the head’s chassis.

Now, I may be an idiot and have not noticed this “hum” before and I do know a little “noise” is normal. It’s just when I turned the amp on I really noticed it one day.

The amp works fine, no problems. Same old set-up, nothing new added (e.g., pedals, new guitar/pups).

What I am wondering, though, is this something problematic that I show worry about and could lead to a problem down the road?

 

[diamondschwin]

do you mean the power transformer or output transformer?

 

[Motorgear]

The one on the side of the rectifier tubes (not sure if it's the power or output transformer, I haven't a full schematic available).

Facing the head, that would be the side with the On/Off, Standby switches.

 

[Boogiebabies]

I had this happen on one of my DR's. Put the amp in diode mode and pull the rectifier tubes. Start the amp and see if the hum goes away. The only thing I could guess was the rectifier tubes were going bad and were drawing too much current, even though they were not being used. If the hum is gone, replace your rectifier tubes. Not only did mine hum, but it got hot too. It stopped with a fresh set of 5U4's.

 

[Pinetree]

If you play it with any kind of volume... you won't be able to hear the hum.

:shock:

 

[Motorgear]

Boogiebabies: Thanks for the suggestion. Tried it, unfortunately amp still hums.

Used a metal rod to see if I could locate the problem more directly (like a listening to a car’s timing) and the sound is most definitely coming from the transformer.

 

[Micah]

My Triple does the same thing--they all do that from
what Ive expirienced and its because of the fact that
all power supplies make a certain amount of noise,
and you are take ing your guitar, which for all intensive
purposes(through the strings and pickups) is a microphone.
You are hearing magnetic noise from your power supply
through your speakers. Flip your amp on with the guitar
disconnected and put you ear next to the side near the
power inlet/rectifier tubes and you will be able to hear
noise if the room is quiet--like a hum. Hope this answers
it for you--its normal!
:wink:

 

[allcountyfair]

my triple recto is brand new and i just turned it on with the guitar unplugged and i heard the same hum you are talking about. I guess it is normal.

 

[Motorgear]

Thanks for the info, guys. I appreciate it. It’s nice to know, now, that the amp isn’t going to blow.

As an aside, I am surprised I haven’t heard it clearly before. I suppose my wife’s right and I am going deaf… ;-) Thanks again.