Questions regarding building the CMoy

[tropicalrips 0]

"chao ta" op-amp

from my pic, the (+) is on the left (-) on the right

the power goes to pin 4 (-) & pin 8 (+) on the op-amp

[augustineRS 0]

tropicalrips,

is it possible to have pic of the underside of the cmoy u showed me?

thanks

[tropicalrips 0]

sure

Edited November 23, 2003 by tropicalrips

[augustineRS 0]

thanks.

will get my parts tmr.

if i need help will drop msg here.

thanks again

[augustineRS 0]

sorry, possible to show the pic with the components mpunted from the other side?

i'm totally lost as to how the jumpers/wiring goes.

 

thanks

[kenshinz 0]

Tropicalrips, what are those pointy little things by the side and bottom of your cmoy ? For connection to the 3.5mm jacks ? Where did you get them from ?

[Firefox 0]

sure

You need a hotter soldering iron.

[tropicalrips 0]

Tropicalrips, what are those pointy little things by the side and bottom of your cmoy ? For connection to the 3.5mm jacks ? Where did you get them from ?

they are there to improve the sound mar

isolators made with hot glue-gun

the ones on top are pins used on PC, u can connect them to IDE cable, they can also be cut to different length, can get them in SLS or SLT

its a re-worked board, i hav changed the resistors on this board about 3 times, so the solder looks funny

 

firefox, i'm using a weller 921ZX up to 450 degrees, don't think its not hot enough

Edited November 24, 2003 by tropicalrips

[jasonhanjk 0]

Sounds like too hot.

[tropicalrips 0]

Sounds like too hot.

i normally use at 300-350 degrees

 

orderd OPA2134pa & LM6172in today to try out

any comments?

 

the LM6172 is suppose to be a high speed op-amp, but not as stable, so can use it to test how good the board is rite?

 

can the cmoy work with 3 AA batts? found a new case that will fit the micro cmoy & hold 3 AA batts

[jtfoo 0]

Sounds like too hot.

the LM6172 is suppose to be a high speed op-amp, but not as stable, so can use it to test how good the board is rite?

 

Read up Tangent's article on dealing with cranky opamps. I've swapped my CD player opamp to the LM6172 and I used 0.1uf polypropylene caps to bypass the power to the opamps. Very stable. YMMV.

[tropicalrips 0]

I've swapped my CD player opamp to the LM6172 and I used 0.1uf polypropylene caps to bypass the power to the opamps. Very stable. YMMV.

the 0.1uf polypropylene caps will replace the rail-spilter? or the power caps (i'm using 25v 470uf) or its added on to these 2 components?

on tangents site this cap is optional & the C3 2.2uF cap as well, only when "all else fails"

 

in his "notes on OP Amps page" his test amp for this op-amp only the R3 & R4 was change (R3=120k , R4=470k) the rest of the amp is the same as the original Cmoy

 

should i try this test amp layout first or go for the design below?

[jasonhanjk 0]

Hey hey. You're are upgrading you amp every now and then. Going at this rate, you will be bringing another PPA to the January meet.

[jtfoo 0]

The 0.1uF is actually C2+ and C2- on your attached picture from Tangent's site. It will NOT replace the power supply cap. This 0.1uF should be placed as close as possible to the opamps, if you read Tangent's article properly. In fact best is directly solder on the leg of the opamps.

 

Here's a pic of on the underneath of my CDplayer with the bypass caps. Right under the legs of the opamps.

[tropicalrips 0]

Hey hey. You're are upgrading you amp every now and then. Going at this rate, you will be bringing another PPA to the January meet.

i'm still trying to build my super-charged Cmoy

for me the PPA is too big as a portable amp, i want somthing thats the same size or smaller then my mp3 player.

maybe pimeta in the near future

 

one more thing guys, the AD823 is "rail-to-rail" what does that mean? it will work without the rail-spilter?

 

i'm looking at the super-mini now since i hav the AD823 op-amp