Built and sounds great. It's like a germanium version of the Woolly Mammoth/Mastotron but with mid-range switch, instead of bass. I found it to be more useful. I used a pair of GT320V PNP and added a charge pump board.
For anyone attempting to build this - I thought it would be worth mentioning (as I have encountered this over multiple builds of this circuit) that sometimes - depending on transistor gain and passive part variances - the gate doesn't do anything with a 100k pot. If you up the gate pot to 250k, this is usually sufficient to make it clamp down at some point in the sweep of the potentiometer. If you look up the original schematic for this circuit, you will notice a "gain trim" pot connected to the 22k, 2.2k resistors and 47uF cap near the gate connections. I believe this was added by the designer in order to mitigate this. I have yet to try a build with one to verify, since I don't want to order any 250R trimmers, and swapping the 100k gate pot with a 250k one seems to work well enough whenever this issue arises.
Built and sounds great. It's like a germanium version of the Woolly Mammoth/Mastotron but with mid-range switch, instead of bass. I found it to be more useful. I used a pair of GT320V PNP and added a charge pump board.
ReplyDeleteFor anyone attempting to build this - I thought it would be worth mentioning (as I have encountered this over multiple builds of this circuit) that sometimes - depending on transistor gain and passive part variances - the gate doesn't do anything with a 100k pot. If you up the gate pot to 250k, this is usually sufficient to make it clamp down at some point in the sweep of the potentiometer. If you look up the original schematic for this circuit, you will notice a "gain trim" pot connected to the 22k, 2.2k resistors and 47uF cap near the gate connections. I believe this was added by the designer in order to mitigate this. I have yet to try a build with one to verify, since I don't want to order any 250R trimmers, and swapping the 100k gate pot with a 250k one seems to work well enough whenever this issue arises.
ReplyDelete