[Rainmaker91]

So I recently ordered an amp kit from Aliexpress that I figured would be a good way to serve as my first DIY build. I'm not sure of the schematics yet since it probably won't arrive in the mail for a month or so. So of course I have some concerns as to what other components I will need to power it and as to how I will go about building the amp case, with shielding and the likes.
 
So for now at least here is the plan:
- Assembling the DIY kit
- Building a power supply (I have no clue on this one)
- Building a wooden case for the amp (I like the look and I have all the tools I need for intricate woodwork)
 
So of-course I have concerns in terms of how I will go about building the power supply, but I will probably not know the needed voltage and ampere until I get to study the schematics for the amplifier. Other concerns would be towards the case that I will be making and how to provide proper grounding and shielding for the components.
 
I have quite a bit of scrap material I can use for shielding and grounding. I have a 3mm thick aluminium sheet, copper piping that can be used for ground and quite a bit of scrap lead that I figured would be great for shielding.
 
I won't say I'm any expert in any of this stuff so I would appreciate any input people may have.

 

[tomb]

You won't like what I will suggest, because IMHO, there were many other better choices if you had spent some time on Head-Fi, first.
 

  So for now at least here is the plan:
- Assembling the DIY kit
- Building a power supply (I have no clue on this one)
- Building a wooden case for the amp (I like the look and I have all the tools I need for intricate woodwork)

 
The primary issue with almost all of the Chinese and ebay amplifier kits is that they almost never have the power supply.  A good power supply can cost as much as the amplifier circuit, itself.  In your case, probably 4-5 times as much.  The specs on that amp refer to "12-20 dual power supply is the default, transformer power 10-30W to recommend low-power ring cattle Requires a separate voltage winding, the main power amplifier can not be shared, to be welded finished board plus 20"
 
I don't have a clue as to half of what that means, especially "low-power ring cattle."  At the very least, it specifies a dual-power supply from 12-20V (I guess) and a transformer rated for 10-30W?  That's a huge transformer.  Plus, for your ~$20 investment, you're now going to have to mess with wiring up a transformer(s) and power mains.  (Do it wrong and it can kill you.)
 
At $19.56, it's not even worth returning it.  I'd quit while you're ahead with this first mistake and refer to something like this to get you properly started:
http://www.tangentsoft.net/audio/cmoy/
 
Sorry to be such a downer, but it's not like you spent your life-savings on this mistake.

 

[Rainmaker91]

sure, at the very least I might be able to use the components from it for something at a later date. As for the power supply I asked them at an earlier date about it but I see that I finally got an answer.
 
saying the following:
 

[color=rgb(51, 51, 51)] Diameter: 76mm, height 3cm, there are some errors Custom rubber ring tank cattle, low noise, vibration minimized! Installation of 5mm turnbuckle installation. Output power of about 23W Class A customized breakpoint sealed cans without plastic core Toroidal transformer dual 15V output pre-amp dedicated price is 20usd .Is that ok ? Best regards [attach]1614362[/attach] [/color]

 
 
Honestly, I don't want to mess to much around with something that in you words "can kill you".
 
As for the CMoy, it's what I originally had planned to build but the price of the components was far to high (in my country) compared to just getting one pre-assembled.
 
I might look in to just getting the components off of Ali-express, or some other site with decent international shipping prices (no idea what store that would be though).

 

[Rainmaker91]

Ok, so lets say I build myself a CMoy instead. Anything I need to look out for in terms of shielding, ground and so on?

 

[tomb]

Ok, so lets say I build myself a CMoy instead. Anything I need to look out for in terms of shielding, ground and so on?

Not really - it's battery-powered, so there's not a lot to worry about. If you have high-impedance phones, you might want to make it with 2X 9V batteries.

Don't be intimidated by the set instructions or the perf board. You can make it on a piece of wood, if need be - just follow the schematic. Also, it's only a few capacitors, resistors and an opamp. Add input/output connectors and a volume pot and that's it. You don"t have to buy the exact parts in Tangent's tutorial - just make sure they're the same ratings. You need to be careful with the opamp, but there are still many to pick from. Oh - use a socket for the opamp. You'll thank yourself later.

 

[Rainmaker91]

Not really - it's battery-powered, so there's not a lot to worry about. If you have high-impedance phones, you might want to make it with 2X 9V batteries.

Don't be intimidated by the set instructions or the perf board. You can make it on a piece of wood, if need be - just follow the schematic. Also, it's only a few capacitors, resistors and an opamp. Add input/output connectors and a volume pot and that's it. You don"t have to buy the exact parts in Tangent's tutorial - just make sure they're the same ratings. You need to be careful with the opamp, but there are still many to pick from. Oh - use a socket for the opamp. You'll thank yourself later.

Sounds good. As for following the exact components or not... I want the best possible solution when I first order since I have to order everything out of country anyway. Would you mind taking a look at the parts after I have found what I want on Mouser?

 

[tomb]

 

Not really - it's battery-powered, so there's not a lot to worry about. If you have high-impedance phones, you might want to make it with 2X 9V batteries.

Don't be intimidated by the set instructions or the perf board. You can make it on a piece of wood, if need be - just follow the schematic. Also, it's only a few capacitors, resistors and an opamp. Add input/output connectors and a volume pot and that's it. You don"t have to buy the exact parts in Tangent's tutorial - just make sure they're the same ratings. You need to be careful with the opamp, but there are still many to pick from. Oh - use a socket for the opamp. You'll thank yourself later.

Sounds good. As for following the exact components or not... I want the best possible solution when I first order since I have to order everything out of country anyway. Would you mind taking a look at the parts after I have found what I want on Mouser?

Sure, but if you are ordering from Mouser, you should be able to get everything on Tangent's Bill Of Materials, I think.

 

[Rainmaker91]

 
Sure, but if you are ordering from Mouser, you should be able to get everything on Tangent's Bill Of Materials, I think.

Yeah, I did that with the resistors and such. I just have a tendency for choosing other brands for some things is all. Most notably Nichicon Fine Gold capacitors instead of Philips, although I am still on the fence whether or not to go for Elna SILMIC II instead 

 
Either way the shopping cart looks like this for now (with CMoy ID at the end):
- 2x Nichicon Fine Gold 220uf 35v (although the Elna caps are just a fraction more so I might change this) C1
- 2x Nichicon 0.1uf 50v C2
- 1x Vishay 330Ω 1/4w  (LED resistor changed due to different LED) RLED
- 2x Vishay 4.7 kΩ 1/4 W 1% R1
- 2x Vishay 100 kΩ 1/4 W 1% R2
- 2x Vishay 1 kΩ 1/4 W 1% R3
- 2x Vishay 10 kΩ 1/4 W 1% R4
- 1x Texas Instruments OPA2132PA OPA
- 1x Cree 3.2 V 20mA LED (hence the different resistor) D1
- 2x Switchcraft stereo jack 3.5mm In/Out
- 1x BusBoard Prototype Systems ST1 (really not sure about this one) Board
 
Optional stuff that is in the cart:
- 1x Mill-Max DIP-8 IC socket 
- 2x Vishay 47.5Ω 1/4w 1% R5
- 2x Keystone 9v battery clip
- 1x Alps 10kΩ Potentiometer SPST
- 1x Apem Knob
 
I'm really unsure about the board, as I really have no idea what would be simplest to work with. Running wires all over the place seems like a less elegant solution, although fully possible. Also, I would really like to use different in and out connectors as I want to be able to move them freely inside the case without moving the PCB. The same can be said about the Potentiometer, but for that one I really have no idea what alternatives exist. 
 
Edit:
Would these do as replacements for the potentiometer and jack sockets?
- Alpha RV24BF-10 Potentiometer
- 2x Rean TRS 3.5mm sockets with solder lugs

 

[30Cal]

I would get a couple other R3 values up through 4.7kohm so you can fine tune the gain.  They're cheap.
 
If I'm reading things correctly, the 2nd pot you have listed is pretty large (about an inch in diameter)?
 
 
 
Decoding the part numbers on the pots is a nightmare.

 

[Rainmaker91]

  I would get a couple other R3 values up through 4.7kohm so you can fine tune the gain.  They're cheap.
 
If I'm reading things correctly, the 2nd pot you have listed is pretty large (about an inch in diameter)?
 
 
 
Decoding the part numbers on the pots is a nightmare.

2.4cm yes. Considering I'm making it as more of an amp that will be placed on the desk while using my laptop and the likes I don't think size would be an immense issue. That said, I have tried looking for a pot that also has a switch in it like the Alps pot. Problem is I can't find one with soldering lugs. Do you think I would be able to use the Alps pot and just solder on wires instead of on the PCB?

 

[tomb]

  I would get a couple other R3 values up through 4.7kohm so you can fine tune the gain.  They're cheap.
 
If I'm reading things correctly, the 2nd pot you have listed is pretty large (about an inch in diameter)?
 
 
 
Decoding the part numbers on the pots is a nightmare.

 
Agreed.  I've been holding back posting just because I've been investigating his RK097 part number.

 
RK0971221Z05
 
However, now that I see it's the same part number than AMB uses, it's OK.
 
Rainmaker91 - you don't need a pot with lugs if you use the perfboard and put the pot on the perfboard.  It's all relative in terms of convenience, because anything is possible.  You can definitely air-wire (dead-bug) it, but it's more convenient if you just place the pins through the perfboard and treat it as another part.
 
You've picked RN55 resistors, which are the best choice.
 
As for you preference for Fine Gold or Elna caps, honestly - that's the wrong application.  The CMoy operates like any other solid-state amp with a pretty good PSRR (Power Supply Rejection Ratio).  You're probably better off with sterling power caps, not caps made specifically to be placed in the signal path.  Both Nichicon Muse Fine Gold (FG) and Elna Silmic RFS II are made to be placed in the signal path.  That's not the application in the CMoy.  The electrolytic caps are there in the power circuit, not in the signal path.  You would be much better off with Panasonic FM, FC, or Nichicon UPW or UHE.  I would strongly suggest that since you're making this up yourself, buy something even bigger - 470uf (25V is plenty) would be great.  This is a great choice:
http://www.mouser.com/ProductDetail/Panasonic/EEU-FM1E471/?qs=sGAEpiMZZMtZ1n0r9vR22ZGaUoI0JcRftqAKGK7s1AI%3d
 
The film caps are different.  They are directly in the signal path.  They're in there because the CMoy is a very simple circuit.  There is nothing whatsoever to protect the opamp if there is some DC offset on your music source.  (DC offset was common in the days of portable CD players when Chu Moy created the circuit.)  I would still include them in there, but there are better choices.  You are much better off with a metalized polypropylene (MKP) such as a Wima, Vishay-Roederstein, or similar.  Pay no attention to the voltage rating.  They will all far exceed the requirements of a CMoy.  Search for the 0.1uf and MKP, instead.  If it was me, pick a Vishay-Roederstein or Wima that meets that rating.
 
The only other thing is that there's nothing special about an LED.  I'd just as soon order them off ebay, but I'm sure the one you picked will do fine.

 

[Rainmaker91]

   
Agreed.  I've been holding back posting just because I've been investigating his RK097 part number.

 
RK0971221Z05
 
However, now that I see it's the same part number than AMB uses, it's OK.
 
Rainmaker91 - you don't need a pot with lugs if you use the perfboard and put the pot on the perfboard.  It's all relative in terms of convenience, because anything is possible.  You can definitely air-wire (dead-bug) it, but it's more convenient if you just place the pins through the perfboard and treat it as another part.
 
You've picked RN55 resistors, which are the best choice.
 
As for you preference for Fine Gold or Elna caps, honestly - that's the wrong application.  The CMoy operates like any other solid-state amp with a pretty good PSRR (Power Supply Rejection Ratio).  You're probably better off with sterling power caps, not caps made specifically to be placed in the signal path.  Both Nichicon Muse Fine Gold (FG) and Elna Silmic RFS II are made to be placed in the signal path.  That's not the application in the CMoy.  The electrolytic caps are there in the power circuit, not in the signal path.  You would be much better off with Panasonic FM, FC, or Nichicon UPW or UHE.  I would strongly suggest that since you're making this up yourself, buy something even bigger - 470uf (25V is plenty) would be great.  This is a great choice:
http://www.mouser.com/ProductDetail/Panasonic/EEU-FM1E471/?qs=sGAEpiMZZMtZ1n0r9vR22ZGaUoI0JcRftqAKGK7s1AI%3d
 
The film caps are different.  They are directly in the signal path.  They're in there because the CMoy is a very simple circuit.  There is nothing whatsoever to protect the opamp if there is some DC offset on your music source.  (DC offset was common in the days of portable CD players when Chu Moy created the circuit.)  I would still include them in there, but there are better choices.  You are much better off with a metalized polypropylene (MKP) such as a Wima, Vishay-Roederstein, or similar.  Pay no attention to the voltage rating.  They will all far exceed the requirements of a CMoy.  Search for the 0.1uf and MKP, instead.  If it was me, pick a Vishay-Roederstein or Wima that meets that rating.
 
The only other thing is that there's nothing special about an LED.  I'd just as soon order them off ebay, but I'm sure the one you picked will do fine.

Lots of things to respond to so I'll part it up for your convenience:
 
Pot: The only reason I started looking at different ones was because I want the option to be able to freely place the volume know where I want it without having to move the board itself. I considered just using the Alps pot (the one linked to on the Cmoy site) and simply solder wires with heatshrinks on to be able to move it around as I want, but I figured I would get solder lugs to make that easier. After quite a few hours looking through Mousers catalog, I see that there are very few that offer the ame as the Alps pot while still having lugs. Thus I think I'll just got with the Alps.
 
caps: I see, I was really wondering about how the power source caps would affect the sound. I mostly found audio caps in use in most stuff I looked up, clearly I looked in the wrong place. I'll take your word on the one you linked and just get a pair of those. Only reason I tend to stick to japanese caps is because I have learnt to look for that when choosing a PSU for my computer and the likes, but I'm sure Phillips is fairly good as well (really have no clue in the electronic components department).
 
Film caps: I'll look for 0.1uf and MKP instead as you sugested, and the proposed brands.
 
LED: Really I jsut picked one, I want a warm white colour instead of the red one that is linked to in the site so I chose another one. Then I used this site to make sure I got the correct resistor for the LED I picked. I assume the source voltage will be 9v.
 
Still not sure about the board though, but I did find a thread in the forums where Fred_fred2004 show how to make one using a board like that.
 
Also, if possible I would love to make it so that I could use a couple of 9v lithium batteries in the amp. Then wire it up so that I could charge them while still in the amp, but I suspect it would be far easier and safer to just make it easy to take them out for charging.

 

[Rainmaker91]

I did a bit of looking again and came up with these replacements as sugested.
 
Caps: just going with the Phillips you sugested.
 
Film caps: one from Wima and one Vishay-Roederstein, no clue if it's what you thought about though (I really should read more up on this stuff).
 
Then I'll find a couple more resistors for the R3 as sugested.

 

[30Cal]

Since you're already going to pay for shipping, I'd go ahead and get the TLE2426 rail splitter if you're going to be using the battery.  
 
And for the C2 cap, I'd look for something in the 0.3-1.0uF range since space isn't going to be that tight for you.
 
 
Jeg reiser til Norge i August.  Vi har et hytte i Kragero.  My local store carries that board shown on Tangent's site.  I'll plan on bringing one or two along (they're $2 each).  I can drop it in the mail for when you decide to build your CMoy V2.0

 

[tomb]

 

   
Agreed.  I've been holding back posting just because I've been investigating his RK097 part number.

 
RK0971221Z05
 
However, now that I see it's the same part number than AMB uses, it's OK.
 
Rainmaker91 - you don't need a pot with lugs if you use the perfboard and put the pot on the perfboard.  It's all relative in terms of convenience, because anything is possible.  You can definitely air-wire (dead-bug) it, but it's more convenient if you just place the pins through the perfboard and treat it as another part.
 
You've picked RN55 resistors, which are the best choice.
 
As for you preference for Fine Gold or Elna caps, honestly - that's the wrong application.  The CMoy operates like any other solid-state amp with a pretty good PSRR (Power Supply Rejection Ratio).  You're probably better off with sterling power caps, not caps made specifically to be placed in the signal path.  Both Nichicon Muse Fine Gold (FG) and Elna Silmic RFS II are made to be placed in the signal path.  That's not the application in the CMoy.  The electrolytic caps are there in the power circuit, not in the signal path.  You would be much better off with Panasonic FM, FC, or Nichicon UPW or UHE.  I would strongly suggest that since you're making this up yourself, buy something even bigger - 470uf (25V is plenty) would be great.  This is a great choice:
http://www.mouser.com/ProductDetail/Panasonic/EEU-FM1E471/?qs=sGAEpiMZZMtZ1n0r9vR22ZGaUoI0JcRftqAKGK7s1AI%3d
 
The film caps are different.  They are directly in the signal path.  They're in there because the CMoy is a very simple circuit.  There is nothing whatsoever to protect the opamp if there is some DC offset on your music source.  (DC offset was common in the days of portable CD players when Chu Moy created the circuit.)  I would still include them in there, but there are better choices.  You are much better off with a metalized polypropylene (MKP) such as a Wima, Vishay-Roederstein, or similar.  Pay no attention to the voltage rating.  They will all far exceed the requirements of a CMoy.  Search for the 0.1uf and MKP, instead.  If it was me, pick a Vishay-Roederstein or Wima that meets that rating.
 
The only other thing is that there's nothing special about an LED.  I'd just as soon order them off ebay, but I'm sure the one you picked will do fine.

Lots of things to respond to so I'll part it up for your convenience:
 
Pot: The only reason I started looking at different ones was because I want the option to be able to freely place the volume know where I want it without having to move the board itself. I considered just using the Alps pot (the one linked to on the Cmoy site) and simply solder wires with heatshrinks on to be able to move it around as I want, but I figured I would get solder lugs to make that easier. After quite a few hours looking through Mousers catalog, I see that there are very few that offer the ame as the Alps pot while still having lugs. Thus I think I'll just got with the Alps.
 
caps: I see, I was really wondering about how the power source caps would affect the sound. I mostly found audio caps in use in most stuff I looked up, clearly I looked in the wrong place. I'll take your word on the one you linked and just get a pair of those. Only reason I tend to stick to japanese caps is because I have learnt to look for that when choosing a PSU for my computer and the likes, but I'm sure Phillips is fairly good as well (really have no clue in the electronic components department).
 
Film caps: I'll look for 0.1uf and MKP instead as you sugested, and the proposed brands.
 
LED: Really I jsut picked one, I want a warm white colour instead of the red one that is linked to in the site so I chose another one. Then I used this site to make sure I got the correct resistor for the LED I picked. I assume the source voltage will be 9v.
 
Still not sure about the board though, but I did find a thread in the forums where Fred_fred2004 show how to make one using a board like that.
 
Also, if possible I would love to make it so that I could use a couple of 9v lithium batteries in the amp. Then wire it up so that I could charge them while still in the amp, but I suspect it would be far easier and safer to just make it easy to take them out for charging.

 
 
Phillips?  You should read more closely: they are Panasonic, a Matsush*ta company product. Actually, they changed their name to Panasonic Corporation,* but maybe that means they're really based in Detroit-san or New Yorkyo.

  For that matter, the Nichicons that I also mentioned are also Japanese, but whatever.
 
You will need to change the LED and/or resistor if you go with 2x 9V.  Keep in mind that all re-chargeables are much less voltage than alkaline.  So when you're talking about a re-chargeable 9V battery, it could only be 7.2V or 8.4V.  I can't speak for Lithium, but if you go with Ni-Cads or NiMH, just look in my signature for "Trickle Chargers for the old PIMETA."  That will work on a CMoy, too.
 
Yes, Fred's tutorial is good and apropos, too.  Follow it if you want, it'll work fine.

 
 
 
* Maybe because internet filters would keep deleting parts of their company name.