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CK2III and Gamma2 Build Questions

post #1 of 36
8/2/10 at 6:25pm
Thread Starter 

 

I'm pretty new to DIY electronics, so sorry if my questions seem elementary/obvious. I've a got friend who's more in the know that can probably help me out with the actual builds, but I want to get things all straight in my head before I start ordering. I'm trying to do as much reading on my own as I can, but it can be nice to get direct answers/confirmations if it's not too much trouble.

 

For the CK2III:

  1. If I want to house the transformer in a wallwart enclosure, do I need anything besides the case, wire, and DIN connectors? Would these DIN connectors be fine: NYS322 and NYS325? I seem to recall reading somewhere MisterX used them in a build. How does the wiring go? Which of these Polycases would be ideal? I was thinking the PM2320 would be my best bet, though if I can go smaller that would be cool.

  2. If I wanted a 3.5mm input jack as well, how is this wired? I've looked at pictures of builds that have done it and it looks like they simply wired the leads of the 3.5mm and RCA jacks together, but I want to know for sure.

  3. Same as above, but for a second 1/4” headphone output jack.

  4. Would C322C104K1R5CA be a fine replacement for the C322C104K1R5TA (C25-C32)? Near as I can tell the only difference is the lead material (solder coated copper clad steel vs tin with nickel underplate and steel core) and ROHS compliance but I was to be sure.  Or would I be better off waiting for it to backorder ship?

 

For the Gamma2:

  1. Similar to the CK2III power question, I was wondering if I can run a o25/o24 combo inside a wallwart enclosure. If so, do I need anything besides the case, wire, and barrel plug? How does the wiring go? Which of the Polycases would be ideal? Again I was looking at the PM2320, though looking at the distances for the PCB bosses, would the PM2425 be a better choice?

  2. To confirm, is this the transformer I would want for the o24?

  3. Would FKP2-100/1000/5 be a fine replacement for FKP2-100/100/2.5 (C15, C17, C21, C23)? Higher voltage rating and tolerance shouldn't matter too much? Or would I be better off waiting for it to backorder ship?

  4. If I'm getting the Chipquik SMD1 removal kit, would the included flux be suitable for the SMD soldering work?  I would imagine it's fine, but its label of Rework Paste Flux slightly confuses me so I want to make sure.

 

This is all I can think of at the moment, though I might have more questions as I go. Thanks in advance.


Edited by WC Annihilus - 8/2/10 at 6:52pm
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post #2 of 36
8/2/10 at 8:07pm

1.  yes i think that is all you need.  the wiring is however you want it.  just make sure the connection on the dins are corresponding.

 

2 and 3.    It goes tip, ring, sleeve. (TRS) Tip is left,, Ring is right, Sleeve is ground.  I always just remember "ring is right" and everything usually falls into place.

 

4.  yes those are fine.  one contains lead, the other doesn't.  a little lead wont hurt ya:)

--------------

 

1.  yes, you can do this but I'm not sure of what enclosure will fit all that.  I personally went with this http://www.newark.com/box-enclosures/b3-080bk/b3-series-enclosure/dp/26K9037  to get a matching look with the y-2.  like this http://www.head-fi.org/forum/thread/85561/post-pics-of-your-builds/7016

 

2.  yes this is the same transformer i used for the 5V psu.

 

3. a higher voltage and better tolerance shouldn't hurt you...

 

4.  yes get chip quick.,  it comes with a nice flux syringe and some alcohol swabs.  This stuff is a must if you've never done smd work before... also this http://store.curiousinventor.com/guides/Surface_Mount_Soldering/101/

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post #3 of 36
8/2/10 at 8:13pm

CKKIII

1) Looks good, double check on transformer size to make sure it fits.

2) That's one way, you can also wire a DPDT switch to select input.

3) Wire them in parallel (linked together).

4) Sure

 

Gamma2

1) Sure
2) Looks reasonable, heatsink the regulator if possible

3) Looks to be same size, should be fine.

4) I don't think you need anything special for SMD soldering.

 

Good luck, both are fun builds that sound good.

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post #4 of 36
8/3/10 at 5:44pm
Thread Starter 

For either the CK2III transformer or the o25/o24 inside a wallwart enclosure, do I need a fuse anywhere in there?

 

For the CK2III, if I wanted to also have preamp RCA outputs, I take it I would do something similar to the 3.5mm input jack?

 

Thanks again for your responses.

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post #5 of 36
8/3/10 at 8:59pm
Quote:
Originally Posted by WC Annihilus View Post

If I'm getting the Chipquik SMD1 removal kit, would the included flux be suitable for the SMD soldering work?  I would imagine it's fine, but its label of Rework Paste Flux slightly confuses me so I want to make sure.

 

I find that the Chip Quik flux ok for desoldering work, but a bit too gummy for SMD soldering.  I prefer liquid flux that you get in a bottle (with an applicator brush attached to the cap).

 

Quote:

For either the CK2III transformer or the o25/o24 inside a wallwart enclosure, do I need a fuse anywhere in there?

 

Yes, always fuse the AC mains live wire.

 

Quote:

For the CK2III, if I wanted to also have preamp RCA outputs, I take it I would do something similar to the 3.5mm input jack?

 

Connect in parallel to the headphone output jack.

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post #6 of 36
8/3/10 at 9:18pm
Thread Starter 

     Quote:

Originally Posted by amb View Post

Yes, always fuse the AC mains live wire.

Would a fuse holder be likely included inside the Polycase enclosures or will I need to purchase one separately?

 

Quote:

Originally Posted by amb View Post

Connect in parallel to the headphone output jack.

     I'd also be able to use a DPDT switch as a selector, yes?

 

Thanks again

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post #7 of 36
8/3/10 at 9:48pm
Quote:
Originally Posted by WC Annihilus View Post

Would a fuse holder be likely included inside the Polycase enclosures or will I need to purchase one separately?


Probably not included.  You could use an inline-holder inside, if you don't mind opening the case to replace a blown fuse.

 

Quote:

I'd also be able to use a DPDT switch as a selector, yes?

 

You could, but a simple DPDT switch would cause the preamp output to "float" when the switch is set to Headphones (and cause the power amp to pick up noise).  If you use a 4PDT switch instead, you could use the extra poles to short the preamp output to ground for each channel:

 

Output Selector Switch


Edited by amb - 8/3/10 at 9:50pm
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post #8 of 36
8/3/10 at 10:04pm
Thread Starter 

Quote:

Originally Posted by amb View Post
You could, but a simple DPDT switch would cause the preamp output to "float" when the switch is set to Headphones (and cause the power amp to pick up noise).  If you use a 4PDT switch instead, you could use the extra poles to short the preamp output to ground for each channel:

    Would a similar issue be present as well if I wanted a switch for a 3.5mm input jack?  Or would DPDT be good enough for that application?

 

Thanks for putting up with my noobish questions.  I'll probably just go ahead and go for it after this and hope for the best.  Can always fix after if need be 

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post #9 of 36
8/3/10 at 10:18pm

Quote:

Originally Posted by WC Annihilus View Post

Would a similar issue be present as well if I wanted a switch for a 3.5mm input jack?  Or would DPDT be good enough for that application?


Sort of.  If one of your inputs is not connected, switching to it would cause your amp input to float and pick up noise.  But this one is not simple to solve.  You can't just arbitrarily short out the unselected input, because if that input source is connected, then its output would "see" the short. You should never short the output of a source of amp as it may cause damage.

 

If you always have both inputs connected, then this will not be a problem.


Edited by amb - 8/3/10 at 10:20pm
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post #10 of 36
8/3/10 at 10:28pm
Thread Starter 

To clarify, if one of the inputs isn't connected, the floating occurs only if I switched to the non-connected input?  So in addition to always having both connected, as long as I didn't switch to the non-connected input it wouldn't be a problem and DPDT would be fine?

 

Thanks again

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post #11 of 36
8/3/10 at 11:18pm

 

Quote:
Originally Posted by WC Annihilus View Post

To clarify, if one of the inputs isn't connected, the floating occurs only if I switched to the non-connected input?


Yes.

 

Quote:

So in addition to always having both connected, as long as I didn't switch to the non-connected input it wouldn't be a problem and DPDT would be fine?

 

Yes.  And the fact that you have a volume control between the input and the amp, means that the input isn't truly "floating".  The volume pot provides a short to ground when it's turned down.  So it's really not a big issue, unlike at the output end.  Very few audiophile power amps have a volume control.

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post #12 of 36
8/9/10 at 8:03pm
Thread Starter 

Just wanted to confirm my thinking on the transformer wallwart wiring for the CK2III.  If I wanted to have a switch on the main amp case, I would need at least 6 connections through the umbilical?  One pair of the primary leads goes to one of the wallwart AC prongs.  The other primary pair would go through one of the umbilical connections and would in turn be connected to one of the switch prongs.  Another wire from the other switch prong would go back through the umbilical and connect to the other AC prong.  Does it matter which of the primary connections (switch or direct) goes through the in-line fuse and live AC prong?  The secondary transformer leads would go through as four separate connections through the umbilical and be hooked up to their respective connections the amp board.

 

Also, for this would I need a 3-prong enclosure with the ground pin?  And if so, would this also go through the umbilical and ground to the chassis, and thus require a ground loop breaker on the main amp board ground?  Or is a 2-prong enclosure sufficient?

 

Similar question for the o25/o24 wallwart enclosure.  From what I gather on the o24 page I don't need a ground and so a 2-prong enclosure would be fine, but I want to make sure.

 

Thanks again.  Hoping to order and get started soon 


Edited by WC Annihilus - 8/9/10 at 8:05pm
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post #13 of 36
8/9/10 at 9:56pm


 

Quote:
Originally Posted by WC Annihilus View Post

Just wanted to confirm my thinking on the transformer wallwart wiring for the CK2III.  If I wanted to have a switch on the main amp case, I would need at least 6 connections through the umbilical?  One pair of the primary leads goes to one of the wallwart AC prongs.  The other primary pair would go through one of the umbilical connections and would in turn be connected to one of the switch prongs.  Another wire from the other switch prong would go back through the umbilical and connect to the other AC prong.  Does it matter which of the primary connections (switch or direct) goes through the in-line fuse and live AC prong?  The secondary transformer leads would go through as four separate connections through the umbilical and be hooked up to their respective connections the amp board.


Running high-voltage AC mains wiring into your main amp case sort of defeats half the reason for having a separate power supply enclosure.  Either 1) Live with having the switch on the power supply box itself, or 2) Use a switched power outlet strip, or 3) use a ε24 and associated parts in your power supply case and run 2 extra wires in the umbilical to the main case, and mount the momentary pushbutton there.

 

Quote:

Also, for this would I need a 3-prong enclosure with the ground pin?  And if so, would this also go through the umbilical and ground to the chassis, and thus require a ground loop breaker on the main amp board ground?  Or is a 2-prong enclosure sufficient?

 

Similar question for the o25/o24 wallwart enclosure.  From what I gather on the o24 page I don't need a ground and so a 2-prong enclosure would be fine, but I want to make sure.

 

If your power supply box or wallwart enclosure is metal, then you should use a 3-prong AC cord and connect the AC ground to the case.  If the casing is plastic or something else that's electrically isolated, then you could make do with only 2 prongs.  Make sure that all AC mains wiring inside is insulated and cannot touch anything else accidentally or come loose.

 

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post #14 of 36
8/11/10 at 2:01pm
Thread Starter 

Hmm... well I guess I'll either skip the switch or put it on the wallwart enclosure.  Anyways, parts are ordered.  Thanks again for all your help.  Hope to get started on this soon 

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post #15 of 36
9/5/10 at 11:38pm
Thread Starter 

 

I was looking at possibly socketing the output transistors for easier potential swapping.  Would TO220 sockets like these ones work?  And if so, would there be any disadvantage/detriment to using them?
 
If the sockets would work, is there any safe, reasonable way to hookup the output transistors temporarily for testing purposes?  Could I just wrap wire around the leads and cover with electrical tape?  And is there a reasonable way to connect the wires to the board without soldering?  Could I just wrap around the board edge since it's so close and doesn't look like there's anything in the way?  I don't mind desoldering simple wire too much, but the less desoldering I have to do the better.
 
Similar question for the rest of the wiring.  Would I be able to just wrap wire around the lugs and cover with electrical tape?  Basically I want to test everything before placing an order for a few things I forgot (particularly heatshrink, and those sockets if they work) in case I need to replace anything and again, the less desoldering the better.
 
For a couple general wiring questions, just wanted to confirm, are these diagrams correct for wiring the switches (4PDT for output on left, basic schematic in middle, DPDT for input on right)?  These are the switches I went with: 4PDT output, DPDT input.  For the 4PDT output diagram, is the PCB ground specified supposed to be the output ground pad or the star ground?  Would having the pre-amp selected also float noise to the headphones and thus I should also wire the headphone outs to the ground throws (like the grey lines)?
4PDTwiring.jpg?t=1283754384  switchschematic.jpg?t=1283754438  DPDTwiring.jpg?t=1283754462
 
And also, since I am using switches for 2 inputs and 2 outputs, where would each of the grounds go?  Would the default (headphone for output, RCA for input) go to the ground pad and the extra (RCA Pre for output, 3.5mm for input) go to the star ground?  Or would I want both of each going to their respective ground pads?  Or should both of each go directly to the star ground?  Or wire the grounds in parallel and then go to the respective ground pad?  Also partially confused since for output there's a single ground pad and the extra RCA Pre has 2 (R/L) grounds needed, and for input there's 2 ground pads and the extra 3.5mm has one ground needed.
 
Hope I didn't screw up the wording too much, first DIY projects >.>.  Thanks again.

Edited by WC Annihilus - 9/6/10 at 12:59am
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