In reference to the pedal I recently built:
https://www.madbeanpedals.com/forum/index.php?topic=35008.0
Consider this schematic:
(https://i.ibb.co/6RRQ0Kf/cfschematic.jpg)
NOTE: Q2 is missed labeled. It is really a 2N2222.
This is my problem. I get a noticeable drop in vol when I turn on the effect, and hardly any response at all, either vol or fuzz, unless the guitar is cranked up. But when it is cranked, it sounds great.
Now I've only been doing this stuff a couple years, and so far I've only been "painting by numbers", and am slowly learning what effect each part makes on the sound.
If I had to guess, I would say maybe adjust the value/taper of the 500KA vol pot, but I wouldn't bet money on it.
Any ideas will be helpful, and as always, TIA
Increase R3 for more volume. Try 470R, or 680R.
Then check the voltage at the collector of Q2. You'll want something around 4.5v. Adjust R5 as needed.
Those steps should fix any volume issues provided there isn't something else going on to cause the problem.
TIP: add a 1k resistor in series between IN and C1. That can help prevent oscillation when the guitar knob is rolled all the way down.
MB, you have given me a lot to go on. Thank You.
Increase R3 for more volume. Try 470R, or 680R.
Please explain why, in this case, when you increase the R, will that decrease I, or increase E?
Then check the voltage at the collector of Q2. You'll want something around 4.5v. Adjust R5 as needed.
This is one of the few things I Do know.
TIP: add a 1k resistor in series between IN and C1. That can help prevent oscillation when the guitar knob is rolled all the way down.]
How does it do it? Do I need to learn more about RC circuits? (we already know the answer is yes ::))
And should I do that all the time, or just for Fuzz?
In conclusion, in your vast experience , should I try to modify the board I have now, or re-work the whole thing on a breadboard, and make another PCB?
Thank You for your time knowledge.
Increase R3 for more volume. Try 470R, or 680R.
It just came to me. this portion of the circuit is series, and I is constant in series, so E has to increase, more E = more Vol, I guess. DUH, sorry
I suggest reading RG Keen's Technology of the Fuzz Face to get started:
http://www.geofex.com/Article_Folders/fuzzface/fftech.htm (http://www.geofex.com/Article_Folders/fuzzface/fftech.htm)
To answer your question, the two load resistors on the collector (as he states) form a fixed voltage divider. When you increase the resistance connected to the 9v source, you are effectively bleeding off less signal to the output hence the volume output gain. It doesn't matter if it's positive or negative ground. The result is the same.
For the 1k resistor at the input, this post is a very good explanation:
https://www.diystompboxes.com/smfforum/index.php?topic=108402.msg988235#msg988235 (https://www.diystompboxes.com/smfforum/index.php?topic=108402.msg988235#msg988235)
Thank You MB