Alternatively, you can install JS Paint as a PWA (Progressive Web App),
but this does not yet support offline use
(as it doesn't include a Service Worker).
It's more like a bookmark (for now), except it runs in a special window.
The user interface for installing PWAs differs by browser and operating system.
On most desktop browsers, the install prompt is in the URL bar.
On mobile, the install prompt is generally found in the menu of browser options.
See
Installing PWAs for visual guidance.
Jc-120 Schematic May 2026
Unfortunately, I couldn't find a publicly available, accurate JC-120 schematic diagram. However, I can provide some basic info on the amp's circuit:
+-----------+ | Input | +-----------+ | | v +-----------+ | Channel 1 | | (Clean) | +-----------+ | | v +-----------+ | Tone Stack | | (Bass, Mid, | | Treble) | +-----------+ | | v +-----------+ | Master Vol | +-----------+ | | v +-----------+ | Channel 2 | | (Crunch) | +-----------+ | | v +-----------+ | Gain Boost | | Switch | +-----------+ | | v +-----------+ | Reverb | | (optional) | +-----------+ | | v +-----------+ | Power Amp | | (EL34) | +-----------+ | | v +-----------+ | Output | +-----------+ jc-120 schematic
The JC-120 schematic is a complex layout that features a dual-channel preamp, a four-stage power amp, and a comprehensive EQ section. Here's a breakdown of the schematic: It's a 120-watt, two-channel amp that features a
The Marshall JC-120, also known as the JCM120 or JC120, is a guitar amplifier head that was introduced in the late 1980s. It's a 120-watt, two-channel amp that features a unique combination of EL34 power tubes and 12AX7/ECC83 preamp tubes. The JC-120 is renowned for its flexibility, allowing players to dial in a wide range of tonal colors, from pristine clean tones to rich, overdriven sounds. The tone stack is designed to provide a
The EQ section is a comprehensive tone stack, featuring Bass, Mid, and Treble controls. The tone stack is designed to provide a wide range of tonal options, from flat and neutral to extreme and sculpted.
Feel free to copy these to your site!
Some of them are rubbish, but a few of them I'm quite happy with.
Right click on the image and select "Save image as..." to download it,
then copy and paste the HTML code below it into your site,
and update the src attribute to point to where you're hosting the image.
Here are some buttons I collected
I don't know where most of these came from, and I've repurposed some of them.