I reviewed the ElectroHarmonix English Muff’n awhile back, eschewing it’s great versatility and hot overdrive tone, how quiet it is with the dual 12AX7 tubes i put in. But after acquiring the AC30, it took on a much different role: It’s become a CLEAN boost pedal for the Normal channel!
In my quest to create a working SWITCHABLE channels for the AC30. The Normal Channel is BLENDABLE with the Top Boost Channel, but not switchable between them. A major flaw, in my opinion. The answer was to use the Radial BigShot ABY pedal, though i may make my own dedicated A/B switch (it’s simple)- the Y switch keeps getting in the way. This also posed another issue: when the overdriven Top Boost is set to an ideal volume level, the clean level of the Normal Channel sounds weak. To even it up, the Normal Channel starts to break up.
Enter the English Muff’n. I swapped the 2 12AX7 tubes with the lowest gain dual triode preamp tube, 12AU7. The overdrive became so weak that with the pedal plugged in to the dimed out Normal Channel, the Volume on the pedal maxed out JUST gives the AC30 a clean signal (the Gain knob set all the way down). The level though is still not the same as the overdriven Top Boost Channel. There is still a noticeable difference between the two.
That said, it was a start- using the English Muff’n this way provides the Normal Channel a much needed set of TONE CONTROLS to shape the sound of that channel. The 1 Volume knob and Brilliance switch is quite limited.
Another thing to know is that the English Muff’n is, in all actuality, a true tube PREAMP. Reading the schematics of the English Muff’n, it’s almost the same as what you’d find in a Marshall amp. That gave me an idea- i can circuit bend this thing! I can increase or decrease the gain not only thru tube rolling, but thru resistor and cap changes.
Fire up that iron!
Examining the schematics, i traced and planned out what components to modify, and struck while the iron is hot! After a day of resistor swapping, plugging in and testing the sound, i found a suitable sounding set of changes that boosted the volume level a bit, while getting the right blend of sweetness. I also found out how some changes make the tone sound brittle, or soft, or muffled, or spike-y. Handy in future amp mods.
The levels are a bit boosted now, though A/B’ing with the TB channel, it still hs a bit of a noticeable difference. Not Done Yet! I didn’t have a couple of cap values, it will have to wait for now.