Bukeroo - Humbucker simulator build report

[slajeune]

Hi All,

I finally had the time to test my design of the buckeroo.  I am pleased to report that it works fine!  I was able to get some nice humbeckerish sounds out of it.  I definately recommand using a trimpot for the 1k resistor to control the amount of gain.

Joep, can you help me out on this one, I had to make the R3 resistance close to 300 ohm to get a nice boost.  From my understanding, the gain is equal to r4/r3 and 2 / .3 = 6.7 for the gain.  But, I can hear only a slight gain, nothing in the order of 6.7 though.  I do suspect that this has something to do with output impedance.  Am I on the right path?

BTW, here is the link for the buckeroo:

http://www.geocities.com/slajeunesse/buckeroo.html

Thanks,
Stephane.

[Ansil]

basically you have built a modified lpb1  which don't get me wrong it is a cool circuit.  but if yo uchage the r4 to 10k  and the r2 to 82k-100k  you will be in the lpb1 range.  and you can bring up the 300 ohms up to around 700 ohms or so to get around the same gain.  at least thats what i got out of the volume meter on the computer.

[smoguzbenjamin]

Dude don't take it too hard on him Ansil, he's learning, and if he designed this with the LPB1 in mind, and added a few lowpass filters etc I think he's done a good job. It's one of the best ways to learn!

[slajeune]

Hi Ansil,

acutally, the circuit isn't based on the LPB1 but a classic potential divider transistor circuit.  I just saw the circuit for the LPB2 and, you are right, they are fairly similar.

Thanks smoguzbenjamin for the kind words.  Actually, I wanted to do something similar to the Seymour Duncan SFX-10 but, without controlling the boost.  Basically, I wanted around 6db boost with a switch to affect the resonnance of a single coil so that the output sounds similar to a humbucker.

I am learning A LOT from this.  I still don't fully grasp all of the transistor theory....

Thanks,
Stephane.

[smoguzbenjamin]

Trannies aren't that difficult. Just do lots of reading and experimenting and try not hitting yourself when you fry a component

[Joep]

Hi Stephane,

I found some interesting article that might help you:
http://www.mitedu.freeserve.co.uk/Design/bjtbias.htm

The voltage gain is indeed about R4/R3.

Bye,

Joep

[Ansil]

Dude don't take it too hard on him Ansil, he's learning, and if he designed this with the LPB1 in mind, and added a few lowpass filters etc I think he's done a good job. It's one of the best ways to learn!

actually i am not cricitcizing i am only saying that if he increase the resitros to that level it will give more of what is desired.

nor am i stating it is based off of it but it is actually close in resistance so why not go all the way as it will eliminate the problems aquired

[Ansil]

Hi Ansil,

acutally, the circuit isn't based on the LPB1 but a classic potential divider transistor circuit.  I just saw the circuit for the LPB2 and, you are right, they are fairly similar.

Thanks smoguzbenjamin for the kind words.  Actually, I wanted to do something similar to the Seymour Duncan SFX-10 but, without controlling the boost.  Basically, I wanted around 6db boost with a switch to affect the resonnance of a single coil so that the output sounds similar to a humbucker.

I am learning A LOT from this.  I still don't fully grasp all of the transistor theory....

Thanks,
Stephane.

try using the inductor formula to increase the resonance that way too.

[smoguzbenjamin]

true. Misinterpretation on my part.