Our new Jose Master Volume Kit was created by request, and is based on the master volume created by amp tech Jose Arredondo in the 70s. Now you can easily add this unique master volume to your 60s/70s/80s Marshall, Marshall clone, or any amp that has a cathode follower before the tone stack (EQ controls).
Jose Arredondo was an amp tech from the southern California area, and gained a lot of recognition as the first guy to work on Eddie Van Halen’s Marshall Superlead. He also did work for many other southern California guitarists. The “Jose Master Volume” mod is the addition of a clipping circuit just after the cathode follower, and the placement of a master volume pot before the tone stack (EQ circuit and controls). It’s also a great way to “tame” a 50 or 100 watt non-master amp, as the clipping circuit adds a characteristic distortion tone, as well as reducing the signal level sent to the tone stack.
We’ve customized the kit to allow for four different configurations. It can be installed as the sole master volume, as a true bypass (switchable) master volume, or either with an existing pre or post phase inverter master volume. No extra chassis drilling is required, as long as you have an extra speaker jack or other un-used jack/hole in the chassis.
All necessary installation hardware (terminal strip, mounting screw and nut, etc.), wiring, and components are included, as well as printed instructions and a wiring layout.
Beginning in 2018, instructions for modification kits are now online for your convenience. This allows us keep our prices competitive, and helps all of us reduce paper waste. Links to PDF files will be included in the order status email when the order ships, and always available in your order history. Please add grangeramp.com to your email whitelist to ensure you receive our emails. Due to time constraints, calls regarding “missing” instructions will not be returned.
DISCLAIMER: User assumes all risks. Performing these modifications will most likely void the warranty on your amplifier. Working on amps can be deadly if you do not take proper precautions. Read and follow the diagram or instructions very carefully. Basic soldering skills and basic user-supplied tools are required. If you are at all unsure of your ability to perform these modifications STOP and take your amp to a professional to be modified. You can also send your amp to us for modification. Contact us for pricing.
DIFFICULTY LEVEL: INTERMEDIATE [Follow safety guidelines for working with electricity. Basic soldering skills and knowledge of working with AC/DC circuits. Identify all terminals of electronic components using data sheets. Read resistor color codes and capacitor values. Measure and connect high and low voltage AC and DC. Understand basic working of vacuum tubes. Use all functions of a multimeter. Understand Ohms law and apply to basic circuits. Work with basic hand and power tools.]