I’ve never been a fan of philips screw heads for that reason. With a flat head, it’s a lot harder to wear away the head, even if it takes a little bit longer to use the screwdriver

I can’t answer the bit about the main driver position (sorry but I don’t have a clue!) but I have the 5751 in the right slot and the original 12AY7 in the left.

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What difference does tube position make? I hear that it sounds different depending on which tube you replace – why is this? Cheers

This is true; tube sequence does have an effect. I don’t know exactly why, but I do know that a 5751 will interact with the raw guitar signal input in a very different way than a 12AY7 will. So I’m assuming that, because the first pre-amp tube in the chain interacts more directly with the raw guitar signal than the second tube, the first tube must have the biggest effect on tone. By the time the signal hits the second tube, it has already been “shaped”.

Think of it like you would making a cup of tea: putting the milk in before the hot water creates a different flavour than putting the milk in at the end (sorry for the corny metaphor but I can’t think of anything better at the moment )

First, you need to make sure you’re using pre-amp tubes. Second, you need to be using tubes that are plate voltage compatible (e.g. 12AX7, 5751, 12AT7, 12AY7, 12AV7 and 12AU7). These tubes can often be mixed and matched safely, but bear in mind that the circuitry of the pedal or pre-amp will have been designed with a specific tube type in mind. So customising in this way can often be a game of trial and error. Also bear in mind that tubes are a bit temperamental, so no 2 tubes will ever be exactly the same (even the same model by the same manufacturer made on the same production line at the same time). Finally, the English Muff’n will interact with your amp, so using it with a Marshall JMP-1 pre-amp and 9200 power amp will create a different sound than if you plugged it into a Fender Twin reverb!

But all the theory is all fine and well. The best guide is your own ears, and tone is a highly subjective thing, so I would recommend playing about with different combinations.

English Muff’n all the way (The Hot Tube sounds, to me, more like a distortion than an OD but with a simple tube swap you can achieve both with the Muff’n). The Muff’n is one of the best sounding pedals out there for what you are looking for. With the mid and low set to full and the treble set to 9 o clock, it rivals the vintage overdrive setting on my Marshall JMP1. This is one of the few pedals where it’s difficult to get a bad sound. My only criticism is that it can sound a bit too bright (but setting the EQ controls the way I said eliminates this).

I intended to buy a 12AX7 to replace one of the 12AY7s but clicked the wrong box on the site I was ordering from (then failed to notice my mistake in the confirmation e-mail). I had mistakenly ordered a 5751 EH GOLD. After the tube arrived and I discovered my glaring error, I tried the 5751 in the right hand slot while leaving the other 12AY7 in the left slot. I was so glad I made that mistake! It warmed up the sound beautifully (reducing the aforementioned treble problem) and added a nice bit of gain (but not too much as to change the overall character of the pedal).

The result is a rich, creamy overdrive reminiscent of Tony Iommi or Angus Young. I think my (accidentally) going for the lower gain tube has given me a nice versatility; turning the gain down a bit gives a nice Stevie Ray Vaughan tone and reducing it further can give a pretty convincing Johnny Marr or, with a nice analog delay, The Edge.

I can definitely recommend this setup going into the clean channel of an amp (therefore almost using it like a pre-amp). Using it on the overdrive channel generated far too much noise for my liking.