[ls206]

Hi! I accidentally posted this is a different section - it's more suited to this one

Pasted:
I've been scanning the forums recently for an easy project to start me off in the world of diy audio.

I've found this easy to follow guide for the cmoy - but I'm having trouble finding the right components and would like to be sure I'm getting the right stuff!

Could I ask a massive favour - if someone could check the parts I've found are correct, and to help me find the ones I'm unsure of or can't find?

C1 - 220uF 25v edited with different capacitor.
C2 - Does this look like the ticket?
RLED - Need a hand here, I'm not quite sure what I'm looking for.
R1 - 4.7Kohm 1/4W
R2 - 100Kohm/1Mohm (??) 1/4W
R3 - 1Kohm 1/4W resistor with gain 11, again, don't know what to look for with regards to "gain"
R4 - 10Kohm 1/4W
OPA - Op-Amp I actually have an Lm4562NA would this work? (and be better?)
D1 - am I being a bit dim? is this any old LED?
IN - 3.5mm jack socket
OUT - 1/4" jack socket
Board - Is this ok?

Still needed - Switch and volume control, oh and battery connector.
switches, lotta choice
Volume controls, need a little help here
battery connector

Is that all I will need? (except enclosure)
I hope this post isn't too long or tedious.
Thank you for reading and for any help you give, it is much appreciated!

Louis.

1st Reply:
Quote:

Originally Posted by JamesL /img/forum/go_quote.gif Welcome to headfi! I'm sure theres someone better qualified to answer, but everything looks fine to me. RLED is used to limit the current to the LED so it doesn't have to be anything fancy. here Gain is a attribute of the amplifier. With a higher gain, you will achieve a higher volume by only turning the knob a little. Since resistors are so cheap, you could get 2 different values to see which one works best for your headphones. I'm no expert, but the lm4562 has the same pin assignments and workable voltage ratings, so I think it would work, but I wouldn't trust myself on that. The protoboard you picked looks like a stripboard, meaning the copper traces follow from end to end. I'm sure you could re-arrange the components to work with the board, but if it were me, I'd just get a 'island' type breadboard, and make solder bridges. Also, theres a DIY section here, which may be a more fitting environment for this topic.

 

[ls206]

I read in another thread that 470uF capacitors are generally used instead of 220uF ones.
so would this capacitor be a better option for C1?

 

[fzman]

the panasonic fm caps are very good -- but they are backordered 3 months! canyou get them from the usa? try digikey.com, who stocks them. the rubycon zl cap listed as an alternative would be good also. as an output coupler, look for a nichicon bp (nonpolar cap) as well. hope that helps.

 

[odigg]

Hi,

Yes, use 470uf capacitors instead of the stock ones. You can also upgrade the input caps from .1uf to .22uf or .47uf. I upgraded mine to .47uf and they are not giving me any problems.

As for the LED any LED will work. The idea is just to get one that doesn't suck up my power (don't get a BLUE ultra bright LED). Depending on the LED you get you'll have to pick the RLED.

Your R2 is wrong. 1M ohm - 1000k ohms. You need 100K.
R3 - just use the recommended one. There is a formula somewhere on tangent's site for changing the gain with resistors.

I would also suggest you get an 8 pin IC (opamp) socket. It's a lot easier if you want to change opamps. You also don't have to worry about overheat it when you solder.

As for the board, it's hard to tell what it looks like from the picture. Can you find anything that is similar to the recommended one? You should be able to use any board as long as you are willing to figure out the connections.

For the switch the Sub-Min Toggle B and Ultra Miniature looks good. As for the volume, I think you might need the dual miniature.

Apart from that you look like you have everything.

 

[ls206]

cheers!
d'oh! didn't look at the availability!
yea, I thought 1M looked wrong, thanks.

Are there any rules for upgrading components? e.g. keeping the same voltage ratings or wotnot.

I'm in the UK and digikey unfortunately charge a small fortune for delivery

Just a thought, could I attach another battery in series?

 

[Iniamyen]

Quote:

Originally Posted by ls206 /img/forum/go_quote.gif cheers! d'oh! didn't look at the availability! yea, I thought 1M looked wrong, thanks. Are there any rules for upgrading components? e.g. keeping the same voltage ratings or wotnot. I'm in the UK and digikey unfortunately charge a small fortune for delivery Just a thought, could I attach another battery in series?

For the power caps you probably want to buy 25V ones assuming you are running from one or two 9V batteries. (Tangent gives some explanation of this on the website.) Going to a higher voltage rating won't benefit you.

I think most of the opamps you might use have max voltage ratings way above 18V so you shouldn't have any problems putting batteries in series to power the amp.

 

[odigg]

Quote:

Originally Posted by ls206 /img/forum/go_quote.gif cheers! d'oh! didn't look at the availability! yea, I thought 1M looked wrong, thanks. Are there any rules for upgrading components? e.g. keeping the same voltage ratings or wotnot. I'm in the UK and digikey unfortunately charge a small fortune for delivery Just a thought, could I attach another battery in series?

While sticking to 25V is best with two batteries, going to a higher voltage with the caps isn't a big deal. If the only capacitors you can find are 50V don't worry about it too much. Just don't go too high (200v!). I think my input caps are 63V and they are working fine.

You can use two batteries in series (or even 3) but it depends on the Opamp. If you go higher than 2 you'll have to think about the resistor for the LED. With the OPA2132PA or even the 2227 you can use 2 batteries without issue.

 

[breakfastchef]

Tangent clearly mentions Mouser, Digikey and Radio Shack for components. I used Digikey and Radio Shack for my builds.

 

[ls206]

Hi, can any one help me with my POT??

on which do I connect: right, left and ground?

thanks

 

[Pars]

Regarding the pot... do you have a meter? If so, ohm it out. Typically, the way it is sitting, there are two rows of 3 pins each. The left most pin in each row would be the ground. The middle pins would go to the amp, L and R channel. The right pins go to the input jacks (L and R). It doesn't matter which row is L and which is R channel... just make sure you don't mix channels within a row.

 

[ls206]

Great thanks

 

[duckiedeity]

on the topic of this thread, I am also building my first cMoy amp and I'm using Tangent's tutorial. I've gone through his "required parts" list and added the first option of each part (except a green LED instead of a red) to a digikey order. unfortunately, they won't let me get just 2 stereo mini jacks (3.5mm) - they say I have to make a minimum order of like 10,000 of those or something stupid like that. so i'm going to get those stereo jacks and the protoboard from Radio Shack. but here is the rest of the list of what I am going to purchase from digikey. can someone tell me what I still need to buy from Tangent's "optional parts" list?

note: I want the power switch built into the volume control, so i think i want the Alps RK097 pot. also, i keep reading that DIP sockets are easier to deal with, but i am a newb so what are we referring to when we say they are easier to deal with? easier than what?

does someone just want to fill out an order list for me? lol. i find this so confusing because some of tangent's "optional" parts clearly are necessary, like a volume control, etc. it would be awesome if someone would fill out a "bill of materials" at digikey, and then list the remaining parts i need to go buy at radio shack (so far those would be the stereo jacks and the protoboard).

 

[odigg]

If you contact digikey live chat and give them the part number for the recommended input/output jacks, they'll give you a list of ones that will work for you. Pick a suitable one. Look at the BOM below to see the part I used. I think it was CP1-3513-ND

You can get the ALPS pot from Tangent's website.

As for the DIP socket. That is basically a socket that you solder to the protoboard. You can then put the opamp in that by just pressing it into that socket. The reason that makes life easier is A). You don't have to worry about burning out the opamp if you solder it directly to the board. B). You can easily remove the opamp to troubleshoot). C) It's easy to switch opamps if you want to try others like the OPA2227 (much better than the recommend one)

My digikey BOM
1 2 2 0 0 P5552-ND 0.42000 $0.84
2 2 2 0 0 P3104 0.86000 $1.72
3 1 1 0 0 OPA2132PA-ND 5.40000 $5.40
4 1 1 0 0 160-1708 0.09000 $0.09
5 1 1 0 0 226-1041 5.24000 $5.24
6 2 2 0 0 2238K 0.86000 $1.72
7 1 1 0 0 AE10034-ND 1.44000 $1.44
8 2 2 0 0 CP1-3513-ND 0.59000 $1.18
9 2 2 0 0 P5554-ND 0.56000 $1.12
10 2 2 0 0 495-1112-ND 0.45000 $0.90
11 1 1 0 0 OPA2227PA 3.96000 $3.96

I purchased the resistors as a assorted pack from Radio Shack. I also purchased the protoboard and dc jack from Radio Shack.

The mint tin I got from the local grocery store

 

[duckiedeity]

Quote:

Originally Posted by odigg /img/forum/go_quote.gif If you contact digikey live chat and give them the part number for the recommended input/output jacks, they'll give you a list of ones that will work for you. Pick a suitable one. Look at the BOM below to see the part I used. I think it was CP1-3513-ND You can get the ALPS pot from Tangent's website. As for the DIP socket. That is basically a socket that you solder to the protoboard. You can then put the opamp in that by just pressing it into that socket. The reason that makes life easier is A). You don't have to worry about burning out the opamp if you solder it directly to the board. B). You can easily remove the opamp to troubleshoot). C) It's easy to switch opamps if you want to try others like the OPA2227 (much better than the recommend one) My digikey BOM 1 2 2 0 0 P5552-ND 0.42000 $0.84 2 2 2 0 0 P3104 0.86000 $1.72 3 1 1 0 0 OPA2132PA-ND 5.40000 $5.40 4 1 1 0 0 160-1708 0.09000 $0.09 5 1 1 0 0 226-1041 5.24000 $5.24 6 2 2 0 0 2238K 0.86000 $1.72 7 1 1 0 0 AE10034-ND 1.44000 $1.44 8 2 2 0 0 CP1-3513-ND 0.59000 $1.18 9 2 2 0 0 P5554-ND 0.56000 $1.12 10 2 2 0 0 495-1112-ND 0.45000 $0.90 11 1 1 0 0 OPA2227PA 3.96000 $3.96 I purchased the resistors as a assorted pack from Radio Shack. I also purchased the protoboard and dc jack from Radio Shack. The mint tin I got from the local grocery store

Thanks, that's incredibly helpful. I will model my digi-key order off of that list there. Would it be difficult to just skip the recommended opamp and defaultly use the OPA2227PA?

also, I am also from Bloomington, IN!

 

[FallenAngel]

1) Use 4.75K for R4 instead of 10K, 11x gain is too high.
2) Use 470uF power capacitors P12388-ND
3) Use 0.22uF input capacitors BC1858-ND
4) Definitely use a socket (and try rolling some opamps). I personally don't think OPA2227 sounds better than OPA2132/OPA2134, but that's just my opinion, everybody has theirs.