Pyledriver Question

[irmcdermott]

I was looking over the schematic and layout for the Pyledriver and had a question. Doesn't the positive lead of C10 have to be connected to the power source as well? I just don't see that on the layout. Am I wrong, or just missing it (still a newb). Just confused. A friend of mine wants me to build him one of these so I was looking at your board. Thanks!

[madbean]

It is connected directly after the 1n4004. The diode serves as reverse polarity protection, except it is done in series with the power supply rather in parallel towards ground. C10 provides the DC filtering.

[irmcdermott]

thanks for the explanation! really appreciate. thanks for all you contribute!

[irmcdermott]

One more question. I was hoping to lay this one out just like the original with the 4 pots along the top. My first thought that I would have to use the Alpha 9mm's. However, I'm having a hard time finding one that is 20kA. Any ideas as to where I can get them or maybe another part that I can use instead? I'm not even sure if the 9mm's are what to use to lay it out like that. Thanks!

[madbean]

I think a 20kB will work just fine there, because all that pot is doing is changing the shape of the frequency curve (actually, I think it moves the peak freq). A linear will work just as well. Alternatively, you could use a 50kB and put a 50k resistor across lugs 3 and 1. That will bump the value down to 25k and change the taper to a more audio-like response.

[irmcdermott]

thank you so much for always answering my questions. you are a gentleman and a scholar!