by antiquekid3 » Sat Feb 06, 2010 6:10 pm
I considered that scratch-and-dent purchase, but I was hoping to really DYI, not buy a premade board. I think I have decided to go down the point-to-point 6SN7 route. I got three fairly well matched GE NIB/NOS tubes today (along with my 5AR4...I got five matched EL34s two weeks ago).
I got most of my components today as well. A few other questions:
With the Blackburn Audio 6SN7 driver board, I found two schematics. One is in the manual, and the other is just an image...both located on the same part of the website. However...there are several components with different values. Both are "Rev. 1" dated 5/7/2008. Weird!! For example, the cathode to ground resistor for the EL34s are 15.6Ω in the manual and 10Ω in the image. There are a few others with different values, too. Quite perplexing...
Also, he has a 10Ω resistor going from the input ground to the circuit ground. What's that for?
With three significant figures, I assume the 15.6Ω resistor needs to be precision. However, can I get away with using a 15.0Ω instead? And what kind of wattage does it need to be?
The feedback capacitor is 390pF. Will 330pF work?
Can you tell I'm very cheap? I'm trying to use local parts that I can get for free or next-to-nothing...! :-) Maybe I'll end up proving (there's a chance!) that it doesn't take a lot of money to make a great sounding amp! Haha!
Kyle