Hi, I recently purchased a new SC20H - serial number starts with M-2022.

Fantastic amp except I seem to have the same noisy / popping fx loop problem that (now that I have done some research) seems to be quite common.

I have tried all the cable switching / buffered / non buffered / true bypass pedal combinations, different wattage, plugged in, not plugged in etc. regardless of combination - when you press the loop switch it pops and raises the noise floor so it sounds as if you have engaged a noisy overdrive.

Is this simply a design flaw or a faulty unit? I read that it was a problem when it was released but the newer ones were supposed to address this?

Cheers, 

Dylan

Recently I heard a loud pop when going from standby to the 40 watt channel.  Amp still seems to work ok but since then there is a kind of minor but noticeable high pitch sound when on that 40 watt channel.  Cant hear it when on 20 watt.   You can hear it with nothing plugged into the amp and also when my guitar is plugged in.   The only noise noticeable before was just the normal kind of hiss sound that seems to be normal.   Also it doesnt get worse or better by turning the volume up or down.  Its just kind of there from the moment you click it on to the 40 watt.   Can hear it on clean channels also.   I'm 90 percent sure it seemed to have started right after that loud kind of pop when going from standy to the 40 watt.    Any thoughts or ideas on how to solve this?    Thanks for any input!!

Hello Everyone, 

I bought the Marshall code 100 Head as a second hand after watching the positive reviews of it, and I really liked the sound and its features!

I plugged it to a 1 x 12 Cabinet and it works good except for my big disappointment with the hissing white noise that i was getting even when the master volume knob on the amp is turned all the way down. 

I tried every simple solution that i could come with, including turning off the computer in the room, I tried resetting the Amp to factory settings,  I even installed the new firmware from the marshall website.  but none solved this issue.
Does anyone know the solution for this problem? 

Thank you very much in advance

Hossam Othman

Hi!

I bought a Marshall CODE 100w in Feb/21. It wasn't even used 10 times.

Yesterday when I went to turn on the equipment, the amplifier started to make a noise. I thought it might be the cable, but it wasn't.
Even without the cable connected to the equipment, the noise continued.

I reinstalled firmware but it didn't work either.

I do not know what to do.

Could you please help?

Hi everybody

My CODE 25 was working like a charm. After the firmware update there is a horrible whistling high frequency noise coming out from it. It is really bad. 

Anybody can help me out with this? How to roll back the firmare?

(It's not the guitar/cable/ground because I have another amp and I did a test)

Thanks

Matteo 

Hi, so there's a high pitch whining sound coming from my amp both with and without the guitar plugged in, I believe it started around when I first tried the in-built bluetooth feature and think this is the reason for my troubles. The whine starts at 10% on the master volume knob and progressively gets louder as you crank it up

When I tick the 'share audio' button on  my phone, the whining stops, and is replaced by a very managable amount of noise. 

I've already done a factory reset to try and disable bluetooth but the whine is unchanged and bluetooth is still on. I've also tried disabling all bluetooth devices nearby, shutting off my pc, taking away my phones and switching wall sockets (although I haven't tried outside my room yet).

Is there any way to disable bluetooth on the CODE 50? Or maybe I can take it apart and remove the transmitter myself.

Here's a demonstration of me turning on the amp and moving the mic closer (Master volume at 100%)

I noticed my Marshall Code  25 makes a hissing noise when I play through any of the clean amp models. This hissing noise is clearly audible when I play a note on the low E string. It reminds me of an old cassette tape. This is especially apparent with the cab emulation switched off. On the higher strings there is no problem. Is this normal? The hiss doesn't go away with the noise gate turned on.  I have this problem with both firmware versions 1.44 and 1.45. 

OD1 and OD2 getting terrible noise and squealing when Effects loop is engaged. I tried the Boss NS-2 in the loop and it had little effect on it. Loop pedals are TC Electronic Nova Delay, TC Electronic Chorus/flanger, Boss Digital Reverb, Boss NS-2 Noise Suppressor.

Outside the loop is Tuner, Volume pedal, BBE sonic stomp, Rockett Blue note, Wah pedal

I assume its a ground issue interference but no idea how to stop it.

I've noticed that when switching channels, specifically from any other channel to the Clean channel in Green mode, I get an audible pop. Not like a firecracker going off, but definitely bothersome. If I set the Clean channel to Orange mode the pop does not happen. So, the pop only happens when switching to Clean/Green. This pop occurs when switching via the front panel buttons or my midi Voodoo Lab ground Control. 

I've had another JVM410H owner try to reproduce the issue, and they experienced the same pop when switching via the front panel buttons, but did not experience the pop when using the Marshall footswitch.

How can I correct this?

Dsl20 head, on 10w is fine but on 20w there is a thud sound after each note played, any ideas?

Hi there,

I had a Marshall dsl40cr brand new and out the box it "hissed" and "wooshed" quite bad, so much so I had to send it back.

I was sent a replacement that was alot better, but still a touch of noise.

This isn't electrical noise or interference - I know what that sounds like - this is something different.

It's only recently I've been too bothered, as it seems a lot of people have this issue.

My second issues is, when swapping between the 2 master volumes there is a popping noise - that's regardless of if 1 is higher than 2 or vice versa. It's like a static pop and happens via footswitch or on the panel.

I been reading the noise can be due to caps and resistors that need swapping and the popping is due to a faulty controller. Surely if these are known problems, this should be covered.

Any help is greatly appreciated!

Thanks!

Hi Marshall,

 I recently bougth the DSL20CR marshall amp and it makes this noise on ultra gain channel.

https://youtu.be/VbtZsJTpAMs

What can cause this noise, could it be defective? I've tried it in different places in case it could be a power supply interference but the noise is still present.

Thanks in advance.

Regards

After about 3 months of very light usage (home use, ~20 hours), my Code 50 developed a harsh noise problem: https://youtu.be/S2cTK8fsfTE. It's on every preset and can be heard via the speaker and when using headphones. I tried using different guitars/cables/power cords/rooms/outlets, reloading firmware, and resetting the presets to factory default; but the noise continues.  Anything else I can try before I return it for replacement/warranty work?

Hi. I just bought Marshall 1959 HW and it's constantly humming when it's on. I have Wizard Modern Classic Amp and ENGL Powerball 2 and they don't hum like that when ON. Is it normal? Also when I strum a chord very loud mechanical noise going out of the back. Check the video I shot to hear how both issues sound:

My 1974x amp is quiet when nothing is plugged into it, but as soon as I plug my intrument cable into the non-tremolo channel, I get this awful cyclic noise.  Does anyone know what to do?   I replaced the ECC83 tubes one by one (testing it between each tube replacement), but it didn't fix the problem.

Here's a video of my problem.

https://youtu.be/lN_lhUAu7jA

Dear,

I have a new Marshall DSL1CR and it make a popping noise when changing channels from the Ultra gain to Classic gain while playing.

If I mute the guitar, or changing channels from the Classic gain to Ultra gain or using the emulated out there is no pop.

There is same noise when switching off it.

Is it normal or somethings wrong with my combo?

Thanks & best regards.

Hello, admin, why you delete my posts? I bought an expensive amplifier that is noisy and I need a solution to my problem.

I can not send the amplifier back due to the rules of the customs of Russia. It turns out too expensive.
I ask technical support to help me solve the noise problem in the new amplifier. You are, after all, Marshall, not  Noname Firm.

I too am bugged by the constant high frequency whine coming from my Code 50's power section. It has nothing to do with the preamp or patch, but rather the level of the power amp output. It is rather high frequency and constant, and varies a bit when you move your head. But the problem does exist, and it sounds like some high frequencies are not being fitered well by the Code 50 & 100 power supplies or output section. A number of users have now complained about this problem. I have a solid background in electronics and am not a flake! I'm an LA studio musician and this noise is not good for professional recording. I'm hoping it is something that is easily fixable, because I love the sounds I'm getting from this amp.

Hello. 

I've just bought brand new DSL 5 CR. 

When I switch on the combo for the firts time everything is fine. 

Then when I swich off and switch on again I hear three quite loud bang noises. The third bang noise is when the CHANNEL SELECT diode make red or green. 

Is it normal or somethings wrong with my combo? 

Hey Marshall Forum!

About a year ago I bought my first ever Marshall amplifier; the Silver Jubilee 100W head (with 4x12 cab).
Since I use it mostly at home, I haven't cranked the volume all that much. But when I do, I notice a loud humming noise.

Today I turned the amp on, without having the guitar cable attached to it, cranked up the Master volume (with 0 gain!) and it hummed like crazy. 
What could be the source of the humming?? And more importantly, how can I get rid of this awful humming? 

The only cables that were attached were the footswitch, FX in/out and the power cable.