JP2C Noise

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Mariano
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JP2C Noise

Post by Mariano » Tue Oct 31, 2017 6:09 pm

Hi guys,

Just got a JP2C and I'm wondering if this noise is normal or is it a ground loop.

I took the amp out of the rack, it's just the guitar with volume in 0 connected to the amp, and the amp straight to the wall.

I've created a youtube video showcasing this:
https://www.youtube.com/watch?v=nJcsdDrjXLQ

Any ideas here would be appreciated

Thanks!

baron58
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Re: JP2C Noise

Post by baron58 » Tue Oct 31, 2017 8:59 pm

Mariano wrote:Hi guys,

Just got a JP2C and I'm wondering if this noise is normal or is it a ground loop.

I took the amp out of the rack, it's just the guitar with volume in 0 connected to the amp, and the amp straight to the wall.

I've created a youtube video showcasing this:
https://www.youtube.com/watch?v=nJcsdDrjXLQ

Any ideas here would be appreciated

Thanks!

Does the amp make that noise when the guitar cable is unplugged from the amp?

Also the level you tuned up the volume on the high gain, yea that is going to up the noise level as well.

Mariano
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Re: JP2C Noise

Post by Mariano » Tue Oct 31, 2017 10:52 pm

Baron, I just checked and makes the same noise even with the guitar unplugged

I don’t really play at that volume and only went there to hear the noise better. Just making sure that’s the normal behavior of the amp

baron58
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Re: JP2C Noise

Post by baron58 » Wed Nov 01, 2017 8:47 am

When you turn up the volume on any tube amp that raises the noise floor, at 12:00 on that volume you are already close to 100 watts of output power clean. So on the high gain channel with the control up like that I would say that noise is normal. And in the video you don't have the EQ engaged so you have max signal (no scooping of EQ).

Ground loops are pretty audible and noisy even at very low volumes in your case it sounds more like amp white noise which is normal.

Mariano
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Re: JP2C Noise

Post by Mariano » Thu Nov 02, 2017 3:36 pm

baron58 wrote:When you turn up the volume on any tube amp that raises the noise floor, at 12:00 on that volume you are already close to 100 watts of output power clean. So on the high gain channel with the control up like that I would say that noise is normal. And in the video you don't have the EQ engaged so you have max signal (no scooping of EQ).

Ground loops are pretty audible and noisy even at very low volumes in your case it sounds more like amp white noise which is normal.
Thanks!!!

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Markedman
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Re: JP2C Noise

Post by Markedman » Thu Nov 02, 2017 5:08 pm

Normal noise from amp. Do you actually play that loud ever? I did once outdoors.
JP2C, Mark llC++ DG, Mark IV-A/B.

Mariano
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Re: JP2C Noise

Post by Mariano » Thu Nov 02, 2017 6:37 pm

Markedman wrote:Normal noise from amp. Do you actually play that loud ever? I did once outdoors.
Never do but was thinking about getting an attenuator to open the amp more and set it around 10-11 o’clock, as that’s supposed to be the sweet spot

bandit2013
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Re: JP2C Noise

Post by bandit2013 » Sun Nov 05, 2017 10:21 am

The noise is common and normal especially with that level of gain setting. Higher gain channels like CH2 or CH3 will create noise due to the change in gain of the circuits used in the amp compared to that of the clean channel. The hum will get louder if you pulled the gain control (not sure if it was or not in the video). I do not have any amp that is noiseless.

I often run the JP at noon but I am using a 212 cabinet so the overall loudness it not at the same level as it would be with a 412 or two. With the guitar signal the hum or noise floor goes away.

You could add a noise gait in the loop (you will have to keep the loop active for this to work) to reduce amplifier noise when no signal is present (if you needed silence).

baron58
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Re: JP2C Noise

Post by baron58 » Tue Nov 07, 2017 9:33 am

Mariano wrote:
Markedman wrote:Normal noise from amp. Do you actually play that loud ever? I did once outdoors.
Never do but was thinking about getting an attenuator to open the amp more and set it around 10-11 o’clock, as that’s supposed to be the sweet spot
I have the Rivera Rock Crusher and the amp sounds great with it. Don't have to even use the EQ compensation on the rock crusher.

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