The 10ohm resistor matches the resistance/impedance of the speaker that has been removed. All you need to know is that without it the sound may be distorted. In some cases it will work fine without. It’s a case by case basis. If it’s distorted, add a 10ohm resistor and it will probably be fixed.
will this modification give me line-level output? I have a Casio SA-65 and I want to drive a fuzz with it, but signal taken directly from the speaker cable has wrong impedance and doesn’t distort much.
@Rolbista:
I’m not sure what you mean by “taken directly from the speaker cable”. You mean a cable connected directly to the two leads of the speaker while it is active…? Or from the board after the speaker has been removed? The 8 ohm resistor to ground can be helpful and sometimes a limiter resistor in series will help too. The output to the speaker must be hot enough to drive a speaker. That is a lot more signal than a guitar puts out so this will commonly cause problems with certain un-buffered pedals (which distortion pedals often are. Try taking the signal out BEFORE the transistor. This will give you the pre-amplified signal which might be the perfect level for your fuzz.
cheft said:
March 11th, 2010 at 10:10am #
Can you explain the purpose of the 10 ohm resistor and the consequences of not using one?
casper said:
March 11th, 2010 at 1:19pm #
The 10ohm resistor matches the resistance/impedance of the speaker that has been removed. All you need to know is that without it the sound may be distorted. In some cases it will work fine without. It’s a case by case basis. If it’s distorted, add a 10ohm resistor and it will probably be fixed.
chris said:
June 5th, 2010 at 6:50pm #
is the transistor connected to lead or ground
Ryan said:
February 24th, 2011 at 5:02pm #
If a 10ohm resistor is not to be had, would it be best to put one as close to 10 as possible, or non at all?
Ryan said:
March 8th, 2011 at 10:39pm #
Would this work the same way with putting in an XLR plug?
Rolbista said:
January 26th, 2012 at 5:46pm #
will this modification give me line-level output? I have a Casio SA-65 and I want to drive a fuzz with it, but signal taken directly from the speaker cable has wrong impedance and doesn’t distort much.
casper said:
February 16th, 2012 at 8:26pm #
@Rolbista:
I’m not sure what you mean by “taken directly from the speaker cable”. You mean a cable connected directly to the two leads of the speaker while it is active…? Or from the board after the speaker has been removed? The 8 ohm resistor to ground can be helpful and sometimes a limiter resistor in series will help too. The output to the speaker must be hot enough to drive a speaker. That is a lot more signal than a guitar puts out so this will commonly cause problems with certain un-buffered pedals (which distortion pedals often are. Try taking the signal out BEFORE the transistor. This will give you the pre-amplified signal which might be the perfect level for your fuzz.