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um... I want to build a dr boogie!!!!!!

Started by mop-head, November 15, 2006, 11:17:49 AM

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mop-head

 :-[ I have been looking round your site for a few days now. I am a beginner at this diy stuff, so this seemed a great place to start. Problem is, the great sounding Dr Boogie i planned to make, well, i cant find the schematic! Am i missing something, but people are saying that it's great, but i can't build it to find out for myself!!!

joecool85

Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com


joecool85

Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

XinTX

So, for a complete electronics doofus (such as myself), is this a pre-amp or just an FX stomp box?  Or both?


teemuk

That's semantics: Define preamp anyway... Let's quote wikipedia: "A preamplifier (preamp) is an electronic amplifier which precedes another amplifier to prepare an electronic signal for further amplification or processing". This is actually both an excellent but amazingly vague description. So, FX box is essentially a preamp as well as FX box. Even boost pedals that do plain voltage amplifying are FX pedals - and preamps. "Buffers" do not create any kind of audible effect so they do not fall to category of FX pedals but they are still preamplifiers - and can be pedals. Confusing, huh?

In some cases you have "passive" preamps and effects that do not use active electronics. They do "amplify" but in a sense that they often have what is considered as a "negative gain". Some passive circuits can have positive gain if they exploit resonance (i.e. LC circuit). Basically the only thing they can't do is to introduce power gain. All of this can be housed inside a box and declared as "effect" as well.

And what would happen in a scenario where you would move the outboard FX pedal effect inside the amp. Will it become a preamp then - and if it will why wasn't it already? All of this is pretty confusing if you think of it too much so I suggest you don't worry too much about semantics issues. ;)

What your question likely should be is does the concerned pedal introduce any voltage gain and if it does then how much? What is the nominal output signal amplitude you get with the concerned pedal? Do you need more voltage gain (another preamp) to match this to the input sensitivity x of your power amplifier? These kind of questions make more sense.

XinTX

#6
So, again citing my lack of electronics knowledge, does this provide a voltage gain?  If you ran the output of this into a power amp, would that drive a speaker and would this provide an effective control to condition the signal going into the power amp?  Or would it need another amplification stage before it would provide a useful input to a power amp? 

It does appear to have some amplification potential via the JFETs in the circuit.  I just don't know if it will provide sufficient signal boost to feed a power amp.