Vintage “British” Vacuum Tube Pre-Amp

Congratulations on your acquisition of the Electro-Harmonix English MUFF’n, our vintage “British” vacuum tube pre-amp. This uniquely powerful tool is designed to enhance your music and expand the range of your existing equipment. The English MUFF’n is used to create the sound of 1960s British guitar amp’s pre-amp and tone circuits. Please take a few minutes to familiarize yourself with the English MUFF’n controls and how they work.

The English MUFF’n consists of both a gain stage and a tone control section. The tone control section contains high (treble), midrange, and low (bass) tone controls, which form a traditional “tone stack,“ as used in vintage pre-amp sections of ‘60s British guitar amps. A “tone-stack” refers to how an amplifier is voiced for EQ and Gain in the pre-amp section.  All three EQ controls are interactive, letting the player dial in anything from hard-driving modern distortion to the sweet sustain of classic vintage models.

As in the classic British amplifiers, the sweetness and power of the tone is a combination of working the preamplifier gain against the Post gain. The more you turn up the preamplifier, the more saturation of the tubes there is. This results in anything from a sweet and subtle blues overdrive all the way to the classic British stack cranked to the max.

It is easy to set up the Muff’n to give you that sweet Brit sound with an emphasis of any part of the EQ curve. For example, dipping the midrange produces the classic scooped sound. As always, experiment to achieve your own unique sounds. For the first time, you really do have the classic British sound. It is totally dependent on the vacuum tubes. No modeling, no DSP, just the classic sound, which was totally created by vacuum tubes just like the originals. 

GAIN - This controls the intensity of the drive and will provide a stunning range of overdrive selections. Lower settings will give a simple volume boost, while advanced settings will yield screaming solo sounds.
HIGH - Determines the treble response, which tailors the attack and enhances the harmonic content of the pre-amp.

MID - Provides the key to an impressive range of distortion tones. When backed off, the sound is smooth and fat. Increasing the contour changes the character of the mid response and enhances the high and low frequencies.

LOW - Controls the bass frequencies, giving a range from thuddy and heavy to tight and punchy.

VOLUME - Determines the overall output level and amount of boost. Use this to set the level relative to the bypassed sound.

In addition to the input and output jacks at the front of the unit, there is also a STATUS LED. When this LED is lit the English MUFF’n is in the signal path. If the STATUS LED is off then it is in “true bypass” mode, and is completely out of the signal path.

You’ll come to rely on this amp-in-a-box…a bloody masterpiece!

WARNING Your unit comes equipped with a 12 Volt/1 Amp AC external power adapter. Use only the power adapter supplied, and make sure it is appropriate to your location (USA, Europe, Japan, Australia). Use of the wrong adapter can cause damage to the unit or to you, and will void the warranty.