Hopefully a quick question.
Regarding the “distortion adjuster” (for want of a better term), P3, on the front end board of BA3.
Is the absolute value of this pot critical? I forgot to order some 100r trimmers (as per the schematic). I have a few 200r trimmers though. Would they work just as well?
Regarding the “distortion adjuster” (for want of a better term), P3, on the front end board of BA3.
Is the absolute value of this pot critical? I forgot to order some 100r trimmers (as per the schematic). I have a few 200r trimmers though. Would they work just as well?
Sure. Do you have an analyzer to set P3? It seem those who do not are setting their P3 (100r) at the halfway point or 50r. Just measure the 200r pots and set them to 50r before installing. Otherwise roughly 8 turns on 25 turn 200r pot.
P3 sets the balance between Q1 and Q2 The whole point is that it is null at the mid point.
Using a 200r set to 50/150 is going to give an extreme distortion.
Using a 200r set to 50/150 is going to give an extreme distortion.
I would assume to set the 200r to 100r/100r (midpoint) initially?
I have used Room EQ with external audio interface toset the distortion previously on another amp (F5). To be perfectly honest, I ended up just back at the mid point, it seemed to give the best balance z
I have used Room EQ with external audio interface toset the distortion previously on another amp (F5). To be perfectly honest, I ended up just back at the mid point, it seemed to give the best balance z
To me, it seems like the value is pretty arbitrary. I guess 100r means that it actually does something without going massively far from the centre point. You’d need to be right at one end or the other of a 20k before it did anything meaningful to the 10Rs.
My guess is the 200r will be fine. Or even not at all is probably fine also…
My guess is the 200r will be fine. Or even not at all is probably fine also…
On my BA3 pre two full turns on P3 (100r 25t)
Made a significant difference to the sound. I preferred one way and have left it there.
This was established with the audio analyzers on each side of my head, not with measuring instruments.
N.B. if it has not been mentioned, you need to re-bias both channels after altering P3.
Made a significant difference to the sound. I preferred one way and have left it there.
This was established with the audio analyzers on each side of my head, not with measuring instruments.
N.B. if it has not been mentioned, you need to re-bias both channels after altering P3.
