Service Centre for the BIG MUFF

The Big Muff is a timeless classic in the fuzz-pedal world. It’s been heard on numerous recordings and been offered by countless boutique pedal manufacturers in one form or another over the years. There are a bewildering number of different versions of this pedal, which for convenience can be broadly grouped into four categories: vintage USA Big Muff, vintage USA (op-amp) Big Muff, Russian Big Muff, modern USA (NYC) Big Muff.

Many Big Muff users and collectors will tell you that pretty much every Big Muff sounds different, even comparing examples from the same version and/or year of manufacture. We tend to agree with this, based on our experiences servicing these pedals. Apart from normal component variations over time, different component values were often substituted, whether this was intentional or simply a case of running out of certain components, we do not know. We have also noticed different pots fitted to otherwise identical models, which would result in a different sweep altogether !

When considering the reasons for such wide variations in tone & performance with the Big Muff & other E-H pedals, one factor cannot be overlooked. At different times over the four decades of production of E-H pedals, the quality of assembly and in fact quality control in general was pretty poor ! The pedals often looked like they were wired up by someone in a hurry, with soldering that wasn’t going to hold up on the road. This applies to both USA & Russian manufacture.

To give credit where it’s due, however, E-H have come up with some of the most extraordinary pedals over the years. Our personal favourite has to be the Electric Mistress (flanger), for those classic early 80’s guitar sounds, a la The Police, The Pretenders, etc. Once again, there are several versions of the Electric Mistress, and restoring this pedal to full operation can sometimes create challenges for the service tech, depending on the problem.

Recently, a pair of barely functional Big Muff (IC/op-amp) pedals from the late 70’s arrived in our workshop for attention. The two pedals had quite different printed circuit boards, different pots, but almost exactly the same circuit (which we reverse-engineered as the schematics available on the internet often have errors). Even if working properly, these two apparently exactly the same pedals would have sounded very different to each other. You can see from the photo above that the older pedal of the two has been the subject of numerous attempts at rewiring & modification. We ended up correcting & rewiring much of this in order to get the performance on par with the newer of the two pedals.

Amazingly, the pots in both of these pedals work OK, just requiring a squirt of Faderlube to clean & lubricate. The main issues tend to be jacks & switches. The original jacks are cheapo – the best solution is to replace them with Switchcraft jacks. The EQ bypass slide switches are particularly prone to causing loss of signal and should automatically be replaced. Luckily there is an exact size replacement out there. In one of the pedals there was a blown IC and very cheapo IC sockets which just weren’t doing the job, so they were all replaced. Tidy up the wiring & rework any dodgy soldering and we have a pair of working Muff’s, still not quite the same as each other, but much closer than before.

Please contact us by email re any service enquiries for E-H pedals in general, and the Big Muff in particular. In most cases we will be able to assist. We can also supply custom linear power supplies for pedals that require different voltages from the usual 9V DC, ie 18V & 24V DC are sometimes specified by E-H (see previous blog re Rich Split & 18V PSU for example).

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