MIXTEL/ Index

  Small Valve Power Amplifier  

This is very much a "work in progress" item. The amplifier in the above picture is one of a pair that I am currently working on when I find the time.

The original intention was to build to a design discovered in a very old copy of Practical Wireless, but I just couldn't get around to it. However, I discovered that Maplin were producing kits for which they sold PCBs seperately - and the voltage amp/phase splitter circuit happened to be almost identical to the earlier PW offering! So these will probably end up with slight PCB mods to fit the earlier circuit on.

The output stage is a pair of 6L6 valves in push-pull (Maplin used EL34s I think). These are fed into output transformers of very dubious quality. I suspect that they were intended as guitar amp transformers but they were all I could afford at the time. The matching looks about right anyway! I am expecting an output of about 12-15W per channel off these, which should be plenty for my purposes.

No sound quality report yet of course. It is mostly fresh air under the chassis at the moment! I just had to put a picture up for the bloke that did the steel chassis work for me (thanks Dave!). Hopefully putting this onn the web will also galvanise me into some sort of action to actually finish the things!