CODE-100 Fizz noise and crackle noise


My new CODE-100 2x12 has a prominent digital fizz noise it also crackles, very unpleasant specially when you use tremolo, chorus, delays.

Very noticeable on the decay of the notes, decay of notes crackles.

When you play the low E string unfretted it makes a buzzing noise, this is difficult to forgive in any amp.

Are you guys at Marshall aware of this? should I return the amp?

Thank you.

edited 04 Oct 2017 at 03:08 AM

Jorge Liguori (5)

asked 04 Oct 2017 at 02:31 AM

Jorge Liguori (5)
Same issue! - joe Pomponio 12 Feb 2018 at 08:07 PM
Ya, Looks like I won't be recommending Marshall Code-50. I should have went with Fender. What was I thinking? - joe Pomponio 12 Feb 2018 at 08:10 PM
Ok I have a theory. Try changing the pre amp to Acoustic or Natural. It seems to clean up the Buzz. So I think it is a Modeling / software issue. I'll ask Marshall if they can fix it with a software update. - joe Pomponio 12 Feb 2018 at 09:39 PM
I have the same problem with the Marshall code 100 combo
- Adrian Sarbu 17 Nov 2018 at 01:42 PM
I tried all the possible guitar cables, I wired the amplifier even other 220 v plugs - Adrian Sarbu 17 Nov 2018 at 01:46 PM
Answers: 13


Hello Jorge,

The CODE should not be making any fizz or crackle noise. Have you tried using a different cable? Failing that i would return to your dealer for an exchange or refund.

Team Marshall

answered 06 Oct 2017 at 07:40 AM

Hello, I just purchased the same amp and I have the same issue. I went back to the store and tried the other Code 100 they still have in stock. Sure enough, that one is making the same noise. I think It was built that way. Inexpensive parts is my guess to blame. I love the way it sounds, but The more I research this amp about this issue, the more I believe it's just they way it is. I'm surprised this issue wasn't caught during a quality control check. - Joe Teresi 22 Oct 2017 at 10:57 PM
I can't believe Marshall can't put out a bulletin that says put capacitor here? I will probably need to figure it out myself. - joe Pomponio 12 Feb 2018 at 08:14 PM


I'm finding this same issue, digital artifacts distortion under high gain - enough to where it hurts. I can hear strange clicks and fret noise.

I am going to try using a Tube Screamer into a clean amp setting, and see if this solves it. I will respond when I know more.

answered 24 Mar 2018 at 07:22 PM

bluedot studios (1)


Hi Everyone, The Code 100's hum/buzz/noise is the result of this cheep transformer.  The noise is NOT coming from the speakers of the unit.  It is electrical noise coming from the components inside of the amp.  A noise gate WILL NOT FIX the issue! 

I just played a show yesterday with this amp and I was embarrassed when people who don't have a clue about guitar or playing music come up to me to tell me that my amp is making a funny noise. 

I am thinking of selling my amp and trying another.  I was thinking of trying the new Marshall MG102GFX 100-Watt 2x12 Combo. 

answered 26 Mar 2018 at 10:11 PM

Joe Teresi (13)
Because of my last comment, I was contacted by someone from Marshall, Thanks for contacting me. In response to your comments, I have already gone back to the store where I purchased it and we also tested their other unit they have in stock. The other unit was doing the same exact thing. They also contacted the Marshall sales rep and we all concluded that there is no way to eliminate the noise because it's in the design of the amp itself. My question is, how could something like this pass through quality control? - Joe Teresi 27 Mar 2018 at 01:48 PM


Hello Joe,

Regarding your CODE100 we are sorry to hear that you are experiencing a problem with your new amplifier, the amplfier is designed and constructed in our factory with good quality and reliable components. We are always striving for the best quality and reliabilty on all our units so your feedback will be passed on and we can only regret you feel so strongly that you wish to sell your unit. 

We would recomend that you take it back to your dealer so an engineer can service the amplfifer for you and find the source of the noise you are experiencing.

Kind Regards

Marshall Support

answered 27 Mar 2018 at 08:19 AM

Hello from the Serbia. In past few days i had a chance to put my hands on a Marshall CODE 100 combo amp. I bought it as a broken and i tryed to repair it. That is what i do as a part time job as a elecryc engeneer and a musician.. :D The noise comes from the AC component in a DC supply rails. From the IC4 for the bluetooth module specially. What do i do ? I tried to replace all the capacytors and the IC itself. Didnt halp at all ! Next, tried to separate the wires witch goes to the main imput jack,and the processor too and put the ferite core on those wires separatelly. Helps, but still a noise ! .. Next, diconect the power cable for the bluetooth module.. Problem allmost goes away and i am able to hear what i playing.. I suspect thet the problem goes from the two of the1117 IC for the 3.3V and i'm thinking to just put the desing a new circuit to power up a processor and a bluetooth module. For all of you who have a noise problem. you can contact me and i will try to tell you what you should try to do to put down the unwanted noise. That is not a transforator buzz or the ground problem on your guitar ! It is just a DC rail noise. To marshall designers i will recomend you to clean up the desing for that part of the circuit. WE ALL HAWE THE SAME PROBLEM HERE ! You cannot deny it. Next, separate the signal flow cables from the power. That will halp with owerall puckup noise. Hope that you will hear me and try to understand. Amp-s comes noisey from the factorry and that is just sad..
I will send a osciloscope pictures if i need it to.
Now my amp works without a bluetoooth conectivithy. I will sell it and newer buy a new one again !
- Mirko Milosavljević 10 Aug 2021 at 07:08 AM
How can I contact you Mirko? - GERARDO GARZA 17 Oct 2021 at 01:43 AM


I created a youtube video to share.  Please watch and listen with headphones to really hear and understand what I'm talking about here.  Lets all compare notes.  Comment here if you are experiencing the same high pitched noise/buzz issue...

Copy and paste this youtube video address into your browser.  If you still can't find it, do a search on youtube for...

Marshall Code 100 Combo Amp Hum Buzz


edited 27 Mar 2018 at 02:14 PM

Joe Teresi (13)

answered 27 Mar 2018 at 02:12 PM

Joe Teresi (13)
I have exactly the same noise on my CODE 100. It is extremely annoying. - Darin Janke 24 Aug 2018 at 11:54 AM
I have the same problem with the Marshall code 100 combo, i tried all the possible cables, I wired the amplifier even with other 220 V sockets, but the same noise pulls it out, and after 20 minutes of operation the noise increases in intensity - Adrian Sarbu 17 Nov 2018 at 01:53 PM
Hi Adrian,

I would recommend trying a factory reset, if this does not help, I would recommend the amp being looked at by a engineer.

Marshall Support
- Lee Tomlin 19 Nov 2018 at 08:52 AM
Marshall should have these looked at by an engineer and pay for replacement. I have too many issues with this amp that Marshall support either denies knowing about or says that they are working on the issue(s). The previous issue I had to figure out myself. End result I'm going to Fender!! - Jon (Joe) Amaral 24 Jan 2019 at 05:18 PM


Here is another Youtube video I created.  Please listen with headphones to get the full effect...

Just copy the link and paste it into your browser.

PLease add your comments here if you are having the same issue with your Code 100 Amp.  We can compair notes...


answered 27 Mar 2018 at 06:43 PM

Joe Teresi (13)
This is the same noise my Code 50 is making. - Jon (Joe) Amaral 24 Jan 2019 at 05:13 PM
My code 50 after completing a factory reset sound ok for about 10 min. Then started the noise thing. Also volume knobs did not work. Then after powering of and restarting the volume knobs worked, however noise was back. I'm calling Sweetwater (where I purchased) as I don't think we will get any response from Marshall - Jon (Joe) Amaral 29 Jan 2019 at 04:11 PM
Hi Jon,

If you are still having issues it will need to be looked at by an engineer, your dealer where you purchased it from will be able to arrange this for you.

Marshall Support
- Lee Tomlin 29 Jan 2019 at 04:21 PM


Hey Carlos... ok so, I have the same issue, the good folks at Marshall have been working with me to try to resolve this one.  There's bad and some good news here.  I have tested it to the ends of the galaxy, and conclude this is an inherrant feature of the CODE amp.

For me, I cannot get rid of the whine noise completely, it's there, at ZERO volume, and doesn't increase with volume until you add some reverb in the loop.  It seems adding modulation to the loop starts to amplify the annoying signal, which is then boosted by the volume control.

BUT i did discover that if you add a noise suppressor (we use NS2s) at the first point in the loop, it acts a noise gate, and is enough to strangle the inherrant whine going through the loop and then amped.  This does NOT stop the whine at zero levels, but it does do a lot to cut it down, and, prevents the whine from corrupting modulation going through the loop itself, which was my biggest beef.  To cut the whine out completely, we add a weakly set noise supressor (another NS2) on the mic, and this allows us to mic it up without issue.

The CODE is a fabulous piece of kit, coupling up your pedalboard with the inbuilt modelling gives you a hell of a lot of sounds to play with.  Shame the whining puts a dampener on the otherwise excellent amp.

I have ran this past the good folks at Marshall directly, and extensively tested.  Folks aren't going mad I promise.  I have asked Marshall as an ER (enhancement request) to examine the circuit and eliminate this rogue interferrence.  It shouldn't be up to the players to compensate with NS2s, but, compensating with these does allow the amp to function.

Not sure if it helps, but would be inetrested to hear if this does indeed help.

answered 03 Jul 2019 at 03:58 PM

Steve French (1)
Hi Steve. Thanks for you answer... dunno if yours do the same... the fizz and the humm I can handle but not the pops... it's impossible to play something clean in this amp... IMPOSSIBLE... is like the amp is possessed by a gremlin... I have some audio files I can share with you if you want... I dont believe any compressor shall fix this issue... the sad part is that Marshall are aware of all this issues... and nothing happens... is like they gave up on this product and if you have one well bad luck... - Carlos Dagua 05 Jul 2019 at 03:56 AM
Hi Carlos,

Have you installed the latest firmware to help with any issue.

Marshall Support
- Lee Tomlin 05 Jul 2019 at 08:03 AM
Hello. Yes I installed the latest firmware and made a factory reset ... everything was smooth... the bluetooth works fine... the app works fine... can't say the same about the amp :( - Carlos Dagua 05 Jul 2019 at 08:10 AM
Hi Carlos,

I would recommend getting the amp look at by a engineer, if you contact your dealer they will be able to arrange this for you.

Marshall Support
- Lee Tomlin 05 Jul 2019 at 08:26 AM


Simple fix. Lower volume to 4.2 or less, master no higher than 10 o'clock. more crackle.

answered 22 Feb 2019 at 04:17 AM

Rowe Cavelli
I have the CODE 50. I had the same problem but in my case I found that turning up the gate on each of the noisy presets worked well to remove the problem. - Tony Wetherall 12 Jul 2022 at 02:04 PM


I'm having the same issue aswell on the Code 100... even when the the volume is on 0 it makes pops/crackles annoyng sounds, tried several powercords several wall plugs, diferent houses wall plugs... you name it... I'm very disappointed... probably will be my last Marshall

answered 02 Jul 2019 at 11:12 AM

Carlos Dagua


hey so the buzzing and crackling sound goes (almost) away when you pair the 100head with your mobile device.
the problem is with the bluebooth hardware/software.

edited 05 Jul 2019 at 01:09 AM

Arthur Donenfeld

answered 05 Jul 2019 at 01:08 AM

Arthur Donenfeld


Hi Carlos, cheers for the reply back.  OK sounds like yours is slightly different to mine.  My one does not make pops or crackles, and is not affected by connecting bluetooth.  I specifically use an android tablet for the app controls, it works really well.

Do what I did, contact marshall support.  They are super helpful and will try to help.  Marshall sent me a CODE straight off the latest production batch, and left it with me for quite some time to test it before giving the thumbs up.  

Just for reference, my amp did not pop or crackle, it just had a droning whine, which was exasperated by adding modulation into the loop.  I needed the loop as the code has some great drives which you ideally need before modulation, hence it bugged the hell out of me.  Someone linked the exact noise up in the thread.

Anyway I'm waffling...  before giving up on the Marshall, give customer service a call or email, I know they'll be  happy to assist.  The folks I dealt with were excellent.

Cheers, and best of luck, keep everyone posted.

answered 05 Jul 2019 at 08:19 PM

Steve French (1)
Hey guys.

I have also this exact problem. And it makes me absolutley crazy. I bought it at Thomann, and they said. "This amp sounds like this, there is nothing we can do."
I was searching the internet, and there are so many people with this problem. Why don't they solve this problem?

I will contact customer service tomorrow, Probably they can help me.

Good night!
- Kai Stiner 30 Jul 2019 at 11:44 PM


I have the same problem! Its clear to me that there is no fix for this known today. Any posibilitie that Marshall fix this by firmware?

answered 13 Sep 2020 at 01:34 AM

Sebastian Pedemonte


POSSIBLE SOLUTION: Disconnect Bluetooth PCB module from the system.

CASE: Randomly my Amp software started crashing and freezing making bad noises coming from the rev and delay digital modules, if I disable this options the amp stopped the weird noises but also effects, so this is not the best option. For this I looked with an osciloscope all signals and power lines, and Power line shows a lot of noise, also when bluetooth worked the noise increased a lot, yesterday I disconnected the bluetooth module power cable and now seems to be working withouth noises and crashes.

If I get something new I share  here.

answered 11 Jul 2022 at 06:55 PM

Loading - please wait...