All Tube FX Loop

All tube FX-Loop add-on module that can be fitted to virtually any guitar tube amplifier. It has a super flat response for a very transparent output. The module has an all tube signal chain that will add warmth to you pedals going through it. Reverbs and delays sound smoother going through a tube circuit. It has a custom low pass filter to block the harsh high frequencies while keeping clarity. Excellent low end response, so you don't lose any of the thickness of your tone.

Very simple 6 wire install (plus shield grounds where applicable). The module has a built-in voltage regulator to eliminate the need to calculate a voltage dropping resistor, taking all the math and guesswork out of it.

It’s based on 6N17B sub-miniature military grade dual triode. This is a series FX loop, it will pad the send level -20dB or more (adjustable) and can boost the Return input level up to 30dB. Both are adjustable.

Hand made and built with high quality components direct from Mouser Electronics. Neutrik jacks and WIMA film capacitors are used for long life and high reliability.

The 4.2E module has 2 spacing options. It can be configured for 1" or 1.5" jack spacing and will ship with only one jack installed. The second jack and trim pot is included for you to solder at your desired spacing. I can also install both or none of the jacks if you wish.

PCB dimensions are 3"W x 2"D.

          
Loop features adjustable Send and Return levels that can be adjusted externally through the jack  once installed.

Installing this module will require you to work with high voltage. Previous experience with tubes and/or tube amplifiers is mandatory.  It’s recommended to have the module installed by an amp technician. Please use shielded cable for input and output.

Some components may also vary due to availability but will be of same quality and specifications. The 1/4" jacks will always be Neutrik. All modules are hand assembled in the US.

The ground points next to the IN/OUT are for the shielded cable ground and it should only be grounded on this end. Latest version is on the pictured marked "shipped items". Older version pictures are for reference of the jack spacing options only.

Please feel free to contact me if you have any questions or need assistance at

Note: All orders only ship M-F. No shipping during holidays or weekends. Orders placed after X-mas will ship after New Year.