Wednesday 1 January 2014

Happy New Year - germanium Fuzz Face

Happy New Year folks. What cool things do I have to tell you today? Well it's not the new year - in my book nothing changes overnight which always makes the whole new year thing seem pointless and an anti-climax. But I have some cool projects on the go. I bought a great book all about guitar pedals listing the best 101 pedals ever. I couldn't put it down! I decided I had to have a go at making one or two and have picked the Arbiter Fuzz Face as my first one. It's a very simple circuit and a classic pedal from the 60s and 70s. This is one that Jimi Hendrix made famous. You can buy a modern version of it made by Jim Dunlop. But if you want to be cool, you have to have the germanium transistor version of it rather than the modern silicon ones. Experts claim they have a more warmer, less brittle sound. There are many so-called "boutique" pedal makers out there but they tend to be expensive.

The hard part is sourcing the two AC128 germanium transistors because they don't make them any more. Again experts say you need ones with a high gain (called the hfe). So you might find some on Ebay but they might not have the 70-120 hfe the so-called experts insist you need. Well I found some AC128s among my bits and pieces but when tested, had a low gain of about 35-40. But I figured there was  no harm in bread-boarding the circuit with them just to see how they sounded. Bloody amazing! I managed to get some equivalent transistors with higher gains and swapped mine out. I checked the output of the pedal on my oscilloscope and my ears and I can tell you - I couldn't see or hear any difference. So the moral is - don't just listen to what the experts say. Have a go anyway, you might just be surprised. When I get it finished I'll post something on Youtube for you to check out.

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