My original 'GuitFET'... is a pre-amp device with overdrive capability using all discrete single-ended class 'A' circuitry.

Like the GuitFET on the previous page, It uses a FET transistor on the high Z input, and utilizes bass / treble tone controls before a level controlled FET overdrive stage. It has a level control for the input to the tone/drive section as well, giving more control over characteristics. There is also a master volume output control of course.

Below are some pics of the insides, and as you can see, it is quite an affair and pretty  hard to work on. I have had to replace the input FET on two occasions recently due to sporadic voltage conditions in the house I live in. The FET is very sensitive to stray voltages and static, and requires care. I have just installed a terminal block to allow easy replacement of the input FET by just screwing a new one in should it fail - just like changing a valve. I see nothing wrong with this concept. Semiconductor devices are not the forever devices people believe. In my considerable experience of servicing, I have found that transistors are often subject to long term degradation.

Equipment utilising semiconductors has not generally been designed to realise this condition. Engineers and manufacturers build things as if they will never fail. They are built to go forever and thus become too hard to fix when failure occurs. This is fine in a world where no one cares but not so good for those who like a particular thing.

It's also bad news for the environment. (I'm getting on my high horse now...). In no way has the public, the industry or politicians come to terms with the pollution and waste that results from obsolete electronics, and consumer goods generally. Sure we have selective hard rubbish collections and so forth, but I suspect if you followed the truck, it would end up as landfill. The whole thing has been viewed as a one way system. With everything becoming disposable, precious materials are being squandered, and toxic chemicals finding their way into rubbish dumps. Sure, most manufacturers are removing lead from products, but this is just part of the problem. The real problem is rampant consumerism, especially in a country such as Australia which has almost totally vanquished it's manufacturing base in favor of big mining bucks and a phony privatised education system. The emergence of the global Asian manufacturing giants, particularly China, with anonymous factories spewing forth vast ranges of hi-tech products, has broken the link between the supply chain and the end user. Most people are acquiescent or even insouciant to failures or problems with products, mindful of the fact that the "next model will be better...and most likely cheaper." Most modern guitar amps are just as bad. They sport many features but are destined for a short life span, because they are made in the same fashion as consumer electronics.

I somehow feel that this slightly surreal state of affairs will prove to be finite, and ultimately destructive for Western countries such as Australia. It is not a good socio-economic state for a healthy society I think.

I had no plan for the board layout of this. I just ad-libbed.

You can see the broken corner of Vero board. This poor thing has been in and out so many times to make changes I had to patch the board with solder wick.

In the pictures at the bottom you can see where I have installed a PCB mount terminal board to facilitate changing the FET at the input. I thought "why not ..." that's what they did in the valve days.