Marshall Code 25 Review


In this Marshall Code 25 review we’ll take a look at Marshall’s 25 watt digital amp. Not too many companies produce a 25 watt amp, usually opting for a 50 watt amp as a next step up from a practice amp. Why then would anybody go for a 25 watt amp? We’ll take a look at the features, delve in to the pros and cons and finally summarize the Code 25. Right, let’s get started.

Background to Marshall

Marshall made it’s debut in the amplification market with the JTM45 in 1962. Designed and manufactured by Jim Marshall, the company’s founder, and his team. The JTM45 produced 30 watts of vintage style blues and rock through two channels. The 1962 combo was first launched in 1965. Two 12 inch speakers delivered 30 watts of power. The 1962 was used by Eric Clapton among other big name guitarists. The amps evolved and in 1965 a 100 watt valve amplifier, the 1959 Plexi was born and was soon snapped up by Pete Townsend who had been pushing Marshall to make amplifiers.

Marshall released many models over the subsequent decades including the Valvestate series, which featured a mix of valve and solid state technology to bridge the gap between the practice amps and the high end combos. In 2016 the Code series was launched. These digital amps come in 25 watt, 50 watt and 100 watt flavors.

Overview of the Code 25

The code 25 sits in a strange class. Technically it’s a practice amp but with 25 watts of output it’s a very loud practice amp. Coupled with how feature laden it is, it’s an interesting proposition. As you’d expect from a practice amp it’s pretty compact, weighing only 6.1kg.


The closed cabinet construction houses a 10 inch speaker, which delivers 25 watts of output. The styling is simple but classic Marshall. It’s not a bad looking amp with it’s black mesh front and gold color plated control panel. There’s a slightly retro 80’s and 90’s feel to the switches and knobs.

The Code 25 features 24 in-built effects, 5 of which can be used simultaneously. There’s a master volume knob, channel volume knob and gain controls. Additionally there’s a decent amount of control over the EQ with bass, treble and mid controls. It’s important to be able to control the mid on an amp. That’s where the guitar sits tonally when playing with a band a lot of the time.

As well as effects there are also built in pre-amps and cabinet types, allowing you to experience the signature tones of some of the most revered amps of the past. A handy addition is the in-built guitar tuner, handy if you’ve misplaced your clip on tuner! There’s a headphone jack to allow for “silent” practice and an AUX in jack to plug in your phone. That’s really a back-up solution to the Bluetooth functionality, which allows you to connect you phone or a tablet to control the Code 25 remotely.

One connected you can use the free Marshall Gateway app to adjust effects, cabinet types, parameters and positions of presets. The Gateway app allows you to apply your settings to another Code amp, without physically altering the settings. Pretty good if you borrow a friend’s Code for the afternoon.

You can also connect the Code 25 to a PC or Mac using the USB port. This will allow you to record to your DAW. You can also use the My Marshall website to arrange presets, upload and download your custom presets to the community. There are also Marshall featured presets available, which have been curated by Marshall. Using the My Marshall website you can live preview the featured presets via your Code. If you like what you hear you can store it to your amp at the push of a button.

The Code 25 supports a footswitch via a 1/4 inch jack. A footswitch isn’t included but principally it’ll support a four switch unit. The PEDL-91009 is the 4 switch unit, which is programmable, giving you more flexibility. The PEDL-91009 is sold separately and you can expect to pay around $55. Here’s a short overview video of the Code 25.

How Does the Code 25 Work?

Plug your guitar’s lead into the 1/4 inch jack input and flick the power switch and you’re up and running. The display will show you the preset currently in use. Use the preset knob under the display to select one of the 99 presets pre-programmed into the Code 25. Above the EQ control knobs are the pre-amp and effects.

Press the pre-amp button to toggle on and off. You then use the preset knob to select your pre-amp type. You can edit the parameters of the pre-amp by holding down the pre-amp button for a few seconds. This will allow you to edit settings such as tone, ratio and compression for the compressor and drive and tone for the distortion. 

Hit the Pre-FX button to access auto-wah and pitch-shifter. Hold the button to edit parameters such as sensitivity for auto-wah and range of pitch-shift. Hit the Amp button to access a myriad of different amp types, which are broadly split into Clean, Crunch, Overdrive, Natural and Gate type amps. Each section models a classic amp known for their superior tones. For example the JTM45 for clean and the Plexi for overdrive. 

Modulation effects include Chorus, Flanger, Phaser and Tremelo. The parameters can be edited by holding the button for a few seconds. You can also select from 3 delay effects, including reverse for a different spin on delay. There’s also a tap feature, so you can set the tempo of the delay effect. Reverb settings range from room to stadium, all customizeable by holding the reverb switch for a few seconds. The Power switch lets you access various types of power amp. From the Vintage Marshall 30 watt to the 100 watt cabinet. Each setting will provide a different output experience. 

Finally you can select your cabinet type with the cab switch. Select your Marshall style cabinet and the amp will faithfully reproduce it’s tone. From a 4 x 12 inch classic to a 1 x 12 G12M speaker. Play around with combinations of power amps and cabinets to further craft your perfect tone. 

When editing any of the effects, pre-amps, cab settings or power amp settings the amp will show a green LED on the switch when you enter editing mode. When you find the preset you want to edit, press the preset knob to begin editing. Cycle through the editable parameters by pressing the present knob. Twist the preset knob to alter the parameter. To store your changes press the exit/store button until the display begins to flash. Here you can turn the preset button to select a new location to store the changes, or just press and hold the exit/store button again until “stored” appears on the display. That’s all there is to editing presets!

You can further fine tune your tone using the EQ, which includes bass, middle and treble knobs. I always say this, but it’s great to see the mid control. It’s missing in so many amps these days, especially at the 50 watt power range, so it’s great to see that Marshall has included it on the Code 25. 

Connect the Code 25 to your PC or Mac using the USB port. From here you can record directly to your DAW and preview and download presets to your Code 25 directly from the My Marshall website. If that’s not enough you can use the Bluetooth connection to connect your phone or tablet to the Code 25. From here you can re-arrange and edit your presets via the Marshall Gateway App. The app will also allow you to use someone else’s Code amp using your settings. That way they can’t be upset with you for messing with their settings!

You can use the Bluetooth connection or the Aux in jack to connect up your phone to jam along to your favorites tunes. The Bluetooth connection can be a little bit temperamental, but with some perseverance it’s bearable. 

Marshall Code 25 Pros

The Code 25 is a great introduction to modelling amps, and whilst the 25 watts won’t keep up with a band on stage, it’ll certainly make enough noise in a small room and more than enough for your practice sessions. Here are some of the best bits:

  • Great range of in-built effects, amp-styles and cabinet styles
  • Very powerful output for a practice amp
  • The most feature laden amp you can buy for $200

Marshall Code 25 Cons

The Code does suffer from some drawbacks. Dependent on your point of view some of these might be show stoppers. Here are some of the problems:

  • The Bluetooth connection can be a bit patchy
  • Presets need altering when you get started – not really a plug and play type amp
  • Can be a bit fiddly at first until you get your head around it
  • Footswitch is sold separately

Final Thoughts

25 watts is a strange power output. I get that you might want to laden it with features, but why not just do that with a 10 or 15 watt amp? Having said that there’s a lot of headroom to create custom tones with this little amp. Starting with the EQ controls, which includes mid control. The in-built effects are reasonably dynamic. Playing with 5 effects simultaneously should satisfy most guitarists. 

The Code 25 has great software support, with the ability to preview and download presets directly from the My Marshall website. The Gateway app is also a nice touch. The fact that you can load your settings to someone else’s amp without messing with their set up is useful. Connectivity to PC and Mac via USB and the ability to record directly with you DAW is good, perfect if you don’t want to lug a heavy amp to a recording session.

Taking the above into account the Bluetooth connectivity can be a little patchy, which lets it down a little. The presets are ok when you first plug in, but it’s likely you’ll need to play around with them a bit to get them sounding half decent. That’s another thing, it can be a bit fiddly at first until you get used to how it works. However the amount of features you’re getting for the price is pretty amazing. As long as you’re not expecting to take this amp gigging it’ll server you well. 

If you did want a little more ooomph then the Code 50 is $100 more. If I was going for 50 watts I’d probably go for the Boss Katana 50, which is $70 more than the Code 25. You can read more about the Katana in my Boss Katana 50 Review.

I hope you’ve found this post useful. If you have any questions or comments feel free to leave them below. Alternatively you can get in touch using my contact page. Please share this post with anyone who you think might find it useful. As always, happy strumming!

Shop Amazon Check ZZSounds (US)





Note: As an Amazon Associate I earn from qualifying purchases. When you click a link on this page it may go to Amazon or another supplier with whom I have an affiliate relationship. This won’t increase the price you pay. I don’t recommend any product that I haven’t used myself or thoroughly researched.

Marshall Code 25






Overall Quality



  • Powerful Output
  • Feature Heavy
  • Great Versatility


  • Bluetooth Connection Can Be A Bit Patchy
  • Presets Need Configuring
  • Can Be Confusing To Use At First