Ok...now what???
Oct 22, 2002 at 3:45 AM Thread Starter Post #1 of 34

Czilla9000

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I did like you guys told me to to and read tangents guide on building an amp. I also read his guide to "op-amps".


My question is: Now what? What do I do next?


I still am a bit fuzzy on the difference between a meta42 and cha47, and a cmoy...could someone explain? Which should I build (I read tangents guide to cmoy, so if there is one for Meta 42 plz tell me, because I think I can do it).


Also let me get ths streight:

Op Amp: Stands for operational amp. If the sound analog amplifier section. Burr Brown, Nation Semi, and Analog Device build them.


Resistor: Resists a signal, to make sure there is not too much electricity going where you don't want it.

Capsistor: Stores electricity...bigger caps can give bigger bass hits.


Jumper: Basically just like a jumper on a computer motherboard right?



Ok...thanks!
 
Oct 22, 2002 at 4:00 AM Post #2 of 34
Okay I'm a relative new person here too, so maybe I can put this into new person type terms.

The CMOY is the basic amp that tangent has on his website. Original circuit was designed by Chu Moy over on headwize.
Uses the op-amp for both gain and current to drive the headphones. So a single op-amp does all the amplification work.

The CHA47, was a design I guess first implemented by Apheared. It uses parallel op-amps to increase the current handling ability for low impedance headphones like Grados. So this uses two op-amps to do the amplification and driving work.

The META42 is the manufactured PCB designed by morsel, eric343, tangent, and based on apheared's and ppl's buffered amp design. Originally in the ETA42 the buffers (for current) were outside the local feedback loop for the op-amp I believe. The subsequent circuit design uses a multiloop configuration where the buffers are both inside the local feedback loop and also in a global feedback loop for the op-amp. This is supposed to minimize errors (which are better described in the headwize library). So this multiloop buffered design uses the op-amp to provide gain while the buffers provide current, thus op-amp doesn't have to do all the work by itself.

This is just newb talk, so the experts will of course correct my mistakes, please!
Your understanding of basic electronic components seems to be right and about equal to mine. I think the only things I would change would be that a resistor doesn't really resist a signal, it resists electrical current. But since a signal is made up of current you could say it resists a signal.
Caps are kind of like batteries that can discharge really fast and charge really fast. So, when a current drain on a circuit exceeds the ability of the current source, caps can discharge quickly and provide a little extra current.

Again, I haven't studied any physics since freshman year in college so I'm using super basic terms. If anything is wrong please correct.

Sometimes newbs can be helpful to other newbs hopefully.
 
Oct 22, 2002 at 4:10 AM Post #3 of 34
Quote:

Originally posted by mlchang


Again, I haven't studied any physics since freshman year in college



Hehe...I am in 9th grade now and taking physics
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Oct 22, 2002 at 4:11 AM Post #4 of 34
"The META42 is the manufactured PCB designed by morsel, eric343, tangent, and based on apheared's and ppl's buffered amp design. Originally in the ETA42 the buffers (for current) were outside the local feedback loop for the op-amp I believe. The subsequent circuit design uses a multiloop configuration where the buffers are both inside the local feedback loop and also in a global feedback loop for the op-amp. This is supposed to minimize errors (which are better described in the headwize library). So this multiloop buffered design uses the op-amp to provide gain while the buffers provide current, thus op-amp doesn't have to do all the work by itself."


Feedback loop and buffer - what are thoughs?


But a CHA47 is a CMOY with 2 op amps instead of one? Is that all? If so...how do I do it?





Edit: Came up with another question...whats the difference between PCB and protoboard. I see the META uses PCB, while Cmoy uses protoboard.
 
Oct 22, 2002 at 4:48 AM Post #5 of 34
Protoboard
amp-critter-logo.jpg


PCB
pcb-v1.0--01-unpopulated.jpg


Correct? Im still a noob too.
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Oct 22, 2002 at 5:08 AM Post #8 of 34
woo-hoo!!

I'm going to be buying a souped up META42 from JMT soon but would also like to build my own CHA47 or CMOY. What kind of cost would i be looking at for the parts? ~$30?
 
Oct 22, 2002 at 5:30 AM Post #10 of 34
Oct 22, 2002 at 5:33 AM Post #11 of 34
Quote:

Originally posted by Andrew LB
Protoboard
amp-critter-logo.jpg


PCB
pcb-v1.0--01-unpopulated.jpg


Correct? Im still a noob too.
biggrin.gif



That doesn't answer my question.
 
Oct 22, 2002 at 5:41 AM Post #12 of 34
Czilla9000
Quote:

I see the META uses PCB, while Cmoy uses protoboard.


JMT has pcb's for the cmoy. PM JMT. Though I read he was debating about reordering pcb's for the cmoy.
Quote:

That doesn't answer my question.


What was question?
 
Oct 22, 2002 at 6:18 AM Post #13 of 34
Quote:

Originally posted by puppyslugg
Czilla9000

JMT has pcb's for the cmoy. PM JMT. Though I read he was debating about reordering pcb's for the cmoy.

What was question?



My question is: What differentiates PCB from protoboard. I assume PCB is easier to work with. What makes it easier?
 
Oct 22, 2002 at 6:29 AM Post #14 of 34
erm, i think perfboard is a better term than protoboard. perfboard is basically a board with holes in it (sometimes there are copper pads). you basically stick component leads into the holes and solder wires on the other side to connect the leads. pcb (printed circuit board) has copper traces on the other side that connect the components. so with a pcb all you do is stick the component leads into the holes and then solder it to the pad. with a pcb you don't have to connect the leads with wire since the traces already do that.

i've seen the word 'protoboard' to mean various things, such as perfboard, stuff like vectorboard, and i've seen it very commonly used for breadboard.

check out the headwize library. lots of good reading.
 
Oct 22, 2002 at 6:37 AM Post #15 of 34
Protoboard has no 'circuit' on the board. You need to mount parts and run wires from component to component. PCB's has the circuit on the board. All you need to do is mount the parts and solder. Obviouly, pcb's are much easier to work with.

edit: Skippy beat me to the punch. I need to learn how to type!
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