sweet! I'm going to have to build that.
My Texas Instrument 2N1306 is 521A and my 2N1304s are 437A
How do you tell the date? They can't be 1952 and 1947. But they are at least 60's vintage
i just noticed the same. i built it and the trim pot does little to nothing. im trying different Trannies. Si and Ge. i have some old soviet Ge. but doesnt stand up to my cloven hoof IMO.I just finished one myself and the best way I can describe it is ‘timid’. It lacks any real umph. I’m wondering if it’s the 2N1304’s? Also, the trimpot doesn’t seem to have any real affect on the sound.