#1
Alright, I just noticed my amp makes way more hum when I have the FX loop plugged in.

I measured 10 dB more hum. That seems like a lot ain't it? Soon as I unplug both cables, the hum goes away to its "normal" level.. which is about 35 - 40dB when Vol is at 2. I tried each pedal in the loop individually but it's always the same level and having 1 or 3 pedal in the loop dosen't change the hum level. It's no power issue since my pedals in front of the amp are using the same power source (ISO-5). Anyway I switched these cables just to make sure, but it dosent do anything.

Then I tried different cables, but same story. What is weird is that, when the tremolo is on for instance, I can hear the trem in the hum even if I don't play any guitar. Literally the hum is "tremolo-ing"...

Should I bring the amp to a tech (again ) or I am missing something?

Amplifier: Fender Blues deluxe reissue
Last edited by Taz9 at Oct 25, 2014,
#2
Does the hum present itself if you patch the fx send to the fx return and then you insert the loop?
Name's Luca.

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Clue: amplifiers amplify so don't turn it on if you need quiet.
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#3
What do you mean "then insert the loop" ?

I can try to patch from preamp out to preamp in and see what it does, but I'm not sure I get the second half of your sentence.
#4
Im having the same problem with my Peavey valveking 212, but instead I use multieffects processor. I also tried switching the cables and putting the pedal straight into input but it still hums. Guess its the multieffect.. any thoughts?
#5
Yes, run a patch cable from send to return. Apart from testing the pedals and cables it may not be just the noise that is being amplified. You need to know if you are at unity before your measurement of noise is of any value whatsoever.
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#6
Quote by Taz9
What do you mean "then insert the loop"?
Insert it in the circuit, engage it, turn it on.

Also what cath said.
Name's Luca.

Quote by OliOsbourne
I don't know anything about this topic, but I just clicked on this thread because of your username :O
Quote by Cajundaddy
Clue: amplifiers amplify so don't turn it on if you need quiet.
Quote by chrismendiola
I guess spambots are now capable of reading minds.
#7
When I patch from send to return, the static noise gets louder. It's more of a static sound than a hum in the end.

When I measured the static, the sound-meter was against the grill cloth right in front of the speaker. It recorded 30 dB without the patch and about 55 dB with it. But this most not be very accurate since I'm doing it with a cellphone, but still, it gives me an idea.

Insert it in the circuit, engage it, turn it on.


The loop on this amp is always ON. There's no switch.


Also this time, I tried with pedals from different power source. One had a batterie and the other was plugged with an adapter directly in to the wall. Same thing. You can hear the tremolo into the static, and the looper going "click" eveytime the loop start over.
Last edited by Taz9 at Oct 27, 2014,
#8
You may be using less than ideal cables.

Do you have any really high quality cable you can try the amp with?
Also is the hum there when there's nothing connected to the amp's input?
Name's Luca.

Quote by OliOsbourne
I don't know anything about this topic, but I just clicked on this thread because of your username :O
Quote by Cajundaddy
Clue: amplifiers amplify so don't turn it on if you need quiet.
Quote by chrismendiola
I guess spambots are now capable of reading minds.
#9
The cable from guitar to amp input is a Lava Cable when this is happening. I'll try to patch the FX loop with this cable.

Also, there's no static when nothing's plugged in. I'll do it again just to make sure of it.


Edit: Alright I'm done! Time for a tech!
Last edited by Taz9 at Oct 27, 2014,