is it possible to use the EL90/6AQ5 tethrode for building and audio amplifier and if so, does anyone have some kind of a schematic or an idea for building it ?
Yes it will work as an audio amplifier, about 2 watts of audio out. It needs 6.3V for the filaments and about 250V for the plate. It will also require a output step down transformer to match the output impedance to the impedance of a speaker.
Yes it will work as an audio amplifier, about 2 watts of audio out. It needs 6.3V for the filaments and about 250V for the plate. It will also require a output step down transformer to match the output impedance to the impedance of a speaker.
I would use 4 of them. 2 in parallel and 2 in parallel with the two groups in pushpull in class B configuration and you could get about 10 watts out of them.
I would use 4 of them. 2 in parallel and 2 in parallel with the two groups in pushpull in class B configuration and you could get about 10 watts out of them.
There are many hundreds of valve amplifiers circuits on the net, none are likely to use those specific fairly obscure valves though. Biggest problem is aquiring suitable output transformers.
I agree with Nigel. There must be many power tetrode amplifier circuits on the web. As far as the output transformer is concerned you my do a search for Hammond transformers. As I recall they are located in Canada and still produce audio output transformers.
I agree with Nigel. There must be many power tetrode amplifier circuits on the web. As far as the output transformer is concerned you my do a search for Hammond transformers. As I recall they are located in Canada and still produce audio output transformers.
Thanks guys for the replies. First off all I'll try to get my hands on a couple of more of the 6AQ5 tubes. I've found couple of schematics on the net, so when I have 4 tubes I'll try to design a circuit and then I'll ask for your help again