Getting parts for cmoy

[Pagail118]

Hi,

I'm planning to build a cmoy ( well I will get the part for 2 cmoy) and I'm really confuse because english is not my first language and sometimes I just don't understand specified words mean.

I have gotten most of the part and I think I'm good. Here it is :

1 2 OPA2132PA-ND IC DUAL FET HI SP OP-AMP 8-DIP OPA
2 4 P5552-ND CAP 220UF 35V ELECT NHG RADIAL C1
3 4 P3104 .1 UFD POLYPROPYLENE CAP C2
4 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM RLED
5 5 4.75KXBK-ND RES 4.75K OHM 1/4W 1% METAL FILM R1
6 5 100KXBK-ND RES 100K OHM 1/4W 1% METAL FILM R2
7 5 1.00KXBK-ND RES 1.00K OHM 1/4W 1% METAL FILM R3 - 11
8 5 2.00KXBK-ND RES 2.00K OHM 1/4W 1% METAL FILM R3 - 6
9 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM R4
10 1 CP-1414-ND CONN RCA JACK METAL WHT PNL MNT RCA
11 1 CP-1413-ND CONN RCA JACK METAL RED PNL MNT RCA
12 3 CP-3535NG-ND CONN AUDIO JACK 3.5MM STEREO Mini jack
13 1 AE1084-ND CONN USB RTANG FMALE TYPE A SMD USB
14 2 AE7313-ND IC SOCKET .300 8 DIP GOLD DIP-8 IC sockets
15 1 226-2033-ND KNOB CLR GLOSS.50"DIA .250"SHAFT knob
16 1 226-1033-ND KNOB BLK GLOSS.50"DIA .250"SHAFT Knob
17 2 P2U4103-ND POT 10K OHM 12MM HORZ MET BUSHIN Pot
18 5 47.5XBK-ND RES 47.5 OHM 1/4W 1% METAL FILM R5
19 5 2238K-ND STRAP BATTERY 9V I-STYLE 4"LEAD

It's missing the Power switches and I think that's all. I would really like to have a power switch integrated into the volume knob, but I don't know if there is any on Dig-key. If it's not possible, which switches do you suggest me ?

And about the part, is everything ok ? I want it to be able to drive my MS1 that I just commanded.

 

[Seaside]

Your parts list looks all right tho, I may suggest something if you don't mind.

You will probabaly find weak bass with 220uF. I feel like 330uF is ok, but in little weak side. so, try 470uF or even 1000uF. This will help get you little more bass. Only downside of this is, it can drain your battery little faster.

Gain is just too high. If i remember correctly, that is 11 in your case. (1+R4/R3) Set gain about 2 to 3 if you have low impediance phones. You may set it up to 5 when you got high impediance phones, but I do not recommend it. The more gain, the more noise. I think R5 reduces the output level of this amp, which means you may not need it at all when you set your gain low.

Also, you may try 0.47 ~ 1uF film capacitor instead of 0.1uF, if you have enough space with your enclosure.

Regarding RLED, anywhere from 1K to 10K will.. sort of...work. This RLED value determines how bright your LED would be. If this value is small, the LED gets brighter, and that will drain your battery fast, Vice Versa. 10K will work but it looks little too high. You may not notice your LED is on, unless you use high intensity type LED. So, my suggestion here is to use... let's say... 1.5K to 2.2K for standard LED, 4.7K or little higher for high intensity LED.

Hope this helps.

 

[Pagail118]

Thanks alot Seaside ! That really help me !

I will see tomorrow to get the part in place with your suggestions and I will repost it. I still have some time until I get them shipped so I will take my time to get I great first DIY project.

By the way, 32 ohms is considered low ? I imagine compared to 300 ohms + headphones...

 

[Pagail118]

Ok, so I have made changes and now I have some little questions. What is C2 doing, what will it change if I replaced it with 0.47 ~ 1uF instead of .1 ? If it really change alot of thing, where can I find it on digi-key ?

I also have difficulties to find the led, can anyone recommend me one that won't drain to much the battery, I actually want it to be an amp, not a disco light !

And for the pot, and power switch together, anyone know if there is any on digikey ? If not, which power switch should I get ?

If I want to put a DC power jack, which one do you suggest ? there is no one in the part list that is available at digikey.

Last question, Should I remove C5 ?

Here is my list for now.

1 2 OPA2132PA-ND IC DUAL FET HI SP OP-AMP 8-DIP OPA 0 6.53000 $13.06
2 4 P3104 .1 UFD POLYPROPYLENE CAP C2 0 1.04000 $4.16
3 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM RLED 0 0.11800 $0.59
4 5 4.75KXBK-ND RES 4.75K OHM 1/4W 1% METAL FILM R1 0 0.11800 $0.59
5 5 100KXBK-ND RES 100K OHM 1/4W 1% METAL FILM R2 0 0.11800 $0.59
6 5 2.00KXBK-ND RES 2.00K OHM 1/4W 1% METAL FILM R3 - 6 0 0.11800 $0.59
7 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM R4 0 0.11800 $0.59
8 1 CP-1414-ND CONN RCA JACK METAL WHT PNL MNT RCA White 0 0.86000 $0.86
9 1 CP-1413-ND CONN RCA JACK METAL RED PNL MNT RCA Red 0 0.86000 $0.86
10 3 CP-3535NG-ND CONN AUDIO JACK 3.5MM STEREO Mini audio jack 0 1.22000 $3.66
11 2 AE7313-ND IC SOCKET .300 8 DIP GOLD DIP-8 IC sockets 0 1.12000 $2.24
12 1 226-2033-ND KNOB CLR GLOSS.50"DIA .250"SHAFT knob 0 5.45000 $5.45
13 1 226-1033-ND KNOB BLK GLOSS.50"DIA .250"SHAFT Knob Black 0 5.45000 $5.45
14 2 P2U4103-ND POT 10K OHM 12MM HORZ MET BUSHIN Pot 0 3.22000 $6.44
15 5 47.5XBK-ND RES 47.5 OHM 1/4W 1% METAL FILM R5 0 0.11800 $0.59
16 5 2238K-ND STRAP BATTERY 9V I-STYLE 4"LEAD 0 0.74000 $3.70
17 4 P5554-ND CAP 470UF 35V ELECT NHG RADIAL 470 UF C1 0 0.68000 $2.72
18 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM R3 - 2 0 0.11800 $0.59
19 5 4.75KXBK RES 4.75K OHM 1/4W 1% METAL FILM R3 - 3 0 0.11800 $0.59
20 5 2.10KXBK-ND RES 2.10K OHM 1/4W 1% METAL FILM RLED 2.1K 0 0.11800 $0.59
21 5 4.75KXBK-ND RES 4.75K OHM 1/4W 1% METAL FILM RLED 4.75 0 0.11800 $0.59

 

[pddjsteve]

I think the purpose of C2 is to block DC Offset from your source, so that it doesn't get amplified and damage the headphones. I had a .47uF instead of .1 in mine, and I liked it. I think it is supposed to provide a better bass response. I used part #PF2474-ND, which is a panasonic ecw-f series. I'm not sure how that rates as I just kinda picked one, somebody else probably can give a better suggestion.

I like to use the Alps RK097 pot, it has a power switch in addition to volume control. I got mine from Tangent. If you don't want to go that route, I think trying to find the smallest switch is the route to go.

For the 470uF capacitor, you might want to consider part #P12388-ND,it is the same value (470uF) but in the FM series. They're $.50 apeice.

I don't think the LED is going to be that big of a current draw. On my cmoy, I had a really bright blue one and I still had around 40 hours of battery life on an alkaline 9v.

For the DC jack, just look for something isolated, and with the right size for your adapter's plug.

 

[Pagail118]

Ok thanks for the reply

I have change the .1 uf for the .47 part you gave me.

For the pot, I would like to order everything from digi-key, if it's possible. So if there's one like the Alps, I want it

if not then I will need a switch. I would like as much as possible not to have something on the side of my case, so something like really tinny and not long would be the best.

For the 470uf, I had choose the one in my list because it was rated the same voltage, 35V. The price is not that much a difference. I could even go to 1000uf if it will make a difference, but I want the battery to be good so if it's not worth it then I will be better with 470uf.

Any other opinion is greatly appraciated !

 

[pddjsteve]

Well, the part I suggested for the .47uF worked well for me, but I'm not sure if anyone else might be able to suggest a better one. I chose it mainly becase it was smaller than some of the other ones.

I don't know if digikey carries something like the RK097, so you're probably going to need to look for a small switch.

I was suggesting the Panasonic FM series caps mainly because they seem to be regarded as one of the better of the not-crazy-expensive caps. The 25V should be ok if you're using 2 9v batteries, and the size is pretty good. That was how I had mine set up.

 

[Pagail118]

I really have hard time finding the switch

... anyone can point me one, just standard.

The power jack... well can I easily take the radioshack one ? I don't know yet what I will use to supply it.

Here is what I finally think is the good list. I basicly have piece for 2 amp, one portable and one for the home. Different led as I don't know yet what I will use. Is it normal blue take 3V at minimum ?!

1 2 OPA2132PA-ND IC DUAL FET HI SP OP-AMP 8-DIP OPA 0 6.53000 $13.06
2 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM RLED 0 0.11800 $0.59
3 5 4.75KXBK-ND RES 4.75K OHM 1/4W 1% METAL FILM R1 0 0.11800 $0.59
4 5 100KXBK-ND RES 100K OHM 1/4W 1% METAL FILM R2 0 0.11800 $0.59
5 5 2.00KXBK-ND RES 2.00K OHM 1/4W 1% METAL FILM R3 - 6 0 0.11800 $0.59
6 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM R4 0 0.11800 $0.59
7 1 CP-1414-ND CONN RCA JACK METAL WHT PNL MNT RCA White 0 0.86000 $0.86
8 1 CP-1413-ND CONN RCA JACK METAL RED PNL MNT RCA Red 0 0.86000 $0.86
9 4 CP-3535NG-ND CONN AUDIO JACK 3.5MM STEREO Mini audio jack 0 1.22000 $4.88
10 2 AE7313-ND IC SOCKET .300 8 DIP GOLD DIP-8 IC sockets 0 1.12000 $2.24
11 1 226-2033-ND KNOB CLR GLOSS.50"DIA .250"SHAFT knob 0 5.45000 $5.45
12 1 226-1033-ND KNOB BLK GLOSS.50"DIA .250"SHAFT Knob Black 0 5.45000 $5.45
13 2 P2U4103-ND POT 10K OHM 12MM HORZ MET BUSHIN Pot 0 3.22000 $6.44
14 5 47.5XBK-ND RES 47.5 OHM 1/4W 1% METAL FILM R5 0 0.11800 $0.59
15 5 2238K-ND STRAP BATTERY 9V I-STYLE 4"LEAD 0 0.74000 $3.70
16 5 10.0KXBK-ND RES 10.0K OHM 1/4W 1% METAL FILM R3 - 2 0 0.11800 $0.59
17 5 4.75KXBK RES 4.75K OHM 1/4W 1% METAL FILM R3 - 3 0 0.11800 $0.59
18 5 2.10KXBK-ND RES 2.10K OHM 1/4W 1% METAL FILM RLED 2.1K 0 0.11800 $0.59
19 5 4.75KXBK-ND RES 4.75K OHM 1/4W 1% METAL FILM RLED 4.75 0 0.11800 $0.59
20 4 PF2474-ND CAP .47UF 250V METAL POLYPRO .47 uf C2 0 0.79000 $3.16
21 2 P12388-ND CAP 470UF 25V ELECT FM RADIAL 470uf 25V C1 0 0.60000 $1.20
22 2 P12405-ND CAP 1000UF 35V ELECT FM RADIAL 1k uf 35V C1 0 1.15000 $2.30
23 2 PF2105-ND CAP 1.0UF 250V METAL POLYPRO C2 1uf 0 0.96000 $1.92
24 1 516-1310-ND LED 3MM 565NM GRN DIFF LOW CURR Green Led 0 0.62000 $0.62
25 1 516-1311-ND LED 3MM 645NM RED DIFF LOW CURR Red led 0 0.62000 $0.62
26 1 516-1309-ND LED 3MM 583NM YLW DIFF LOW CURR Yellow Led 0 0.62000 $0.62

The only think I am not sure is the C2 cap of 1.0uf, I just look at the same as .47 serie, but at 1.0.

So with this I should be good ?

Help on the switch is appreciated so that I can make it ship on monday morning !

 

[Pagail118]

I have look at the switch and I have some question.

When you look at the function, what's on-on ? those that mean that it's like to switch to another part of the circuit let's say ? And on-off would be like something that cut contact in between two things ?

What's the best for the application ? on-off ? And do I really need to worry about the Rating ?

 

[gsteinb88]

On-On is a single throw switch with 3 pins and 2 positions.
If it is 'up', pins 1 and 2 will be connected, while pin 3 is isolated. If it is 'down,' pins 2 and 3 will be connected while pin 1 is isolated. So, if you only use pins one and two, when it is 'up,' it will close the circuit, allowing current to flow. When it is 'down,' it will open the circuit, turning off the amplifier, and of course not allowing current to flow.
On-Off is the same thing, only it has 2 pins, so that you connect the wires to pins one and two and when it is 'up' the circuit is closed and when it is 'down' the circuit is open.

 

[Pagail118]

Ok thanks,

About the rating, is there anything I should avoid ?

 

[Pagail118]

I just received my parts ! That's the fastest shipping I ever had !