Tell me If I understand this all correctly

Started by RandomRedLetters, August 04, 2005, 09:17:32 PM

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RandomRedLetters

Well Ive worked with electronics before, but not really for audio applications where I need to wire whole circuits. So let me tell you what I think I understand and you can fix any misunderstandings I have.

http://img.photobucket.com/albums/v213/nothingone/CrazyAce.jpg

This is a combo of an electra distortion with a EH boost circuit. I know the 330ohm and 1M in paralelle is redundant, so Im going to remove the 1M resistor in future models. I have a switch to choose between different sets of diodes for a different distortion flavor. At the end of each diode stage is a 10k resistor so once the signal comes out one stage it doesn't just enter back into the second stage (which happened before I added the resistors to each branch)

Now in the interest of not reducing gain, I talked it over with one of the RF engineers at my work (I work in an electronics lab and we test for Boeing, Ratheon, etc) and he said remove the 10k resistors and either use a higher rated diode (like 10v) on each stage before its forked back together so the signal doesnt back track, or I can remove the .1uf cap after the fork and add a polarized .1uf cap on each branch so it doesnt back track. Anyone have any thoughts on this? It seems logically either way would work.

As far as I understand it heres how I break down the use of parts

Resistors: Control voltage or gain

Transistors: Amplify signal

Op-Amo: Amplify signal, also optimized for negative and positive feedback applications (like tremolo)

Capacitor: Controls frequency of signal, and really just a voltage buffer for circuit stages

Diode: Allows current to flow in only one direction

Does this all sound about right? I hope in the few days Ive looked up stuff, I might actually be learning it.

petemoore

2m/470...you'll need a big R there I think, the 470 isn't doing much of anything seriesed with the mammoth 2m, 470k and up to a 'large' [2m is pretty large] R might work there.
 The second transistor needs power supply?
 between the second Q's B and the 10k, I see a paralleled 330ohm and 1meg, the one meg brings the 330ohm, ever so slightly under 330ohm, I think if there's PS to this transistor you'll also need a 'large' resistor from base to V+.
 Whenever R's are seriesed or paralleled, and have a 10x [ and larger]ratio between their values, one of them is redundant or doesn't change the overall R value enough to even marginally change bias.
 Other than that it looks like it'll probably work !!!
Convention creates following, following creates convention.

RandomRedLetters

Quote from: petemoore2m/470...you'll need a big R there I think, the 470 isn't doing much of anything seriesed with the mammoth 2m, 470k and up to a 'large' [2m is pretty large] R might work there.
 The second transistor needs power supply?
 between the second Q's B and the 10k, I see a paralleled 330ohm and 1meg, the one meg brings the 330ohm, ever so slightly under 330ohm, I think if there's PS to this transistor you'll also need a 'large' resistor from base to V+.
 Whenever R's are seriesed or paralleled, and have a 10x [ and larger]ratio between their values, one of them is redundant or doesn't change the overall R value enough to even marginally change bias.
 Other than that it looks like it'll probably work !!!

Yeah, I tried applying +9v to the second transistor, and it just shorted the circuit. (I ended up cutting the wire to disconnect the new +9v, but that shorted out a LED and burnt it out, a guess another trip to radioshack is in order for a new LED)

I agree, after brushing up on ohms laws, I decided to remove some of the redundant resistors.

Its actually a good sounding circuit. The si diodes sound fuzzy, while the LEDs have more of a tube crunch.