[Greendragon]

ok i'm sure you guys are going to laugh at me for asking this, but i have been to http://tangentsoft.net/audio/cmoy-tutorial/

i was interested in it's design and hope to build one soon, but have never worked with circuit boards or anything and could use any help possible, or any other tutorials, already been to the headwize stuff learning about the CMOY style


it was the only site i could find with a step by step guide on how to do this, i've never worked with electronics before... i'm interested about the bottom of the circuit board i've never seen the bottom, i dont understnad if wires go to each thing or what i'm sooo confused lol can anyone help?

PS. i want a volume knob, in/out, on/off switch, LED light to show power's on i will also need help on how to put all that in

 

[JMT]

Welcome to Head-Fi Greendragon.

Maybe I missed it, but is there a specific question in your post? First, look at the schematic. That will tell you what needs to be connected to what. Then, practice your soldering skills. Use some old scrap wire and a cheap RS board. Then practice some more. Then, when you have specific questions post them here.

Good luck, and remember.....this is fun.

 

[Greendragon]

well there's lots of questions i have i've gone thru there and i think i have a parts list so far, i need to know what all to go out and buy...

2x 220 ìF 35V electrolytic capacitor, radial leads
2x 0.1 ìF 50-plus volt full-size film cap
3x 10 KÙ 1/4W metal film resistor
2x 4.7/4.75 KÙ 1/4W metal film resistor
2x 100 KÙ 1/4W metal film resistor
2x 1 KÙ 1/4W metal film resistor, gain 11
1x dual op-amp OPA2132P
1x Power indicator LED, red diffused, 1.8V, 1-5 mA, 3mm
2x Stereo mini jack (3.5mm)
1x Protoboard (Radio Shack # 276-0150)
1x DIP-8 IC sockets, gold contacts
1x power toggle switch
1x volume knob
1-2x 9v battery clip
1x volume control

from the list at http://tangentsoft.net/audio/cmoy-tutorial/intro.html (for the 276-0150 board) it doesnt' show how to put in the volume control knob in... i'm going to be making this from scratch and my first project, i dont have money so i can't afford to mess up

will i need to wire anything on the back of the board? it doesn't show the back of the board if any wires are soldered back there or what..... i'm going to try to put this in an altoids/penguin style case

i know i will need solder and wire, what do you recommend?

i don't have a volt meter or anything to test anything with so i'm goign to have to try to put it together and just hope it works :'(

am i missing anything?

 

[Dreamslacker]

Try getting a 0.22uF capacitor instead of the 0.1uF if the capacitor can fit. The best would be a polypropylene film & foil cap.

It'll be difficult to stick a dual pot in there unless you can get those slim types. Or if you can redesign the circuit for squeezing out more space (I hope you can)..

 

[Greendragon]

what do you mean 2 pots? i only have 1, the volume control does anyone have a more detailed faq. than the one at tangentsoft, i understand that that's pretty straight forward but i get lost when they do the testing and stuff lol

 

[Greendragon]

and is that all the stuff i'll need? i mean if i was going to go buy parts, that's everything i'd need? should i get a cheaper amp or go with that one or what?

when i build that one, there shouldn't be anything on the bottom of the circuit board when i'm done but solder right? no wires or anything like that? all the wires will be on the top?

 

[Dreamslacker]

Quote:

Originally posted by Greendragon what do you mean 2 pots? i only have 1, the volume control does anyone have a more detailed faq. than the one at tangentsoft, i understand that that's pretty straight forward but i get lost when they do the testing and stuff lol

A dual-pot is having 2 seperate potentiometers controlled by one knob. This allows you to control both right and left channels simultaenously. It is one module on it's own. Has 6 legs, 3 for each channel.

Quote:

Originally posted by Greendragon and is that all the stuff i'll need? i mean if i was going to go buy parts, that's everything i'd need? should i get a cheaper amp or go with that one or what? when i build that one, there shouldn't be anything on the bottom of the circuit board when i'm done but solder right? no wires or anything like that? all the wires will be on the top?

I suppose those are the parts you'd need. You could go with the OPA2134PA; It's cheaper than the 2132.

Wires can go above or below the board. It's up to you. I've wires both below & above my pcb on
my amp. Because having them all on top would make it too messy for me.

 

[Greendragon]

u talking about the volume control? then what should i usei see them all in penguin cans or altoid cans have volume knobs figured i could use one too

 

[JMT]

Here is a list of parts that you can order from Newark Electronics:
Resistors: All are metal film resistors

1. R1 - 4.7K ohm - MFR1/4W-1%-4K75
2. R2 - 100K ohm - MFR1/4W-1%-100K
3. R3 - 2K ohm (Gain 6) - MFR1/4W-1%-2K
4. R4 & R6 - 10K ohm - MFR1/4W-1%-10K

The following you can order from Digikey Electronics:

1. C+ & C- - 220µF/25v electrolytic capacitor - P10297-ND
2. C1 - 0.1µF/50v polypropylene capacitor - P3104-ND
3. Op-amp - OPA2134-ND or OPA2132-ND
4. Potentiometer - Panasonic 50K ohm - P2G1503-ND
5. 1/8" mini input/output jack - 84N1196
6. SPDT mini toggle switch - 61F1245
7. LED - Red panel mount - L10051-ND

As far as wire is concerned, I like to use Belden 22awg stranded wire from Handmade Electronics. Hope this helps.

 

[Greendragon]

on the orig. parts list from that site, shouldn't your
R1 be R2/R3*
R4&6 be R1*

i dont see why replace the 10K ohm 1/4W on the parts list with a 4.7 Kohm one

and where does R6 go? lol i'm soooo confused now LMAO

 

[JMT]

Sorry, I was thinking in terms of the Hansen PCB. Just use the part numbers provided for the parts relative to Tangent's schematic.

 

[Dreamslacker]

Quote:

Originally posted by JMT Sorry, I was thinking in terms of the Hansen PCB. Just use the part numbers provided for the parts relative to Tangent's schematic.

I was wondering:

It was stated (in the Meta tutorial) that using the 0.1uF cap with 100K ohm resistor would create significant phase distortion and attenuation up to 100Hz.

So wouldn't it be better to change the 0.1uF to something else like the 0.22uF cap like in the Meta.


Someone care to enlighten me?

 

[Greendragon]

well mine is going to be a cmoy, i figured it'd be the easiest, i dont know if i can afford all the parts though, if anyone has any extra parts on my parts list up there i'd like to know if i could get them sent to me...i'd like to build one but i don t even have a multimeter or those jumper cables or a soldering iron yet

any help would be appritiated

 

[tangent]

Quote:

It was stated (in the Meta tutorial) that using the 0.1uF cap with 100K ohm resistor would create significant phase distortion and attenuation up to 100Hz.

This is true. I didn't talk about anything like that in the Cmoy tutorial to keep it simple, by not deviating too far from Chu Moy's original design (excepting the tweaks section, of course). Given Greendragon's confusion, I hope you're not suggesting that I go and make that tutorial any more complicated?

 

[Greendragon]

woah the man himself heh, very nice tut. man it seemed to include just about everything i needed, except how to hook up the jacks and volume control, and i'd never seen the back of that particular board so without having finally seeing a pic of the back of one finished, and seeing the traces i was really confused cause you did'nt have any pics of the back or with any jacks wired in already