[haejuk]

Looks like the par-metal ones already have vents in them, that is a huge plus.  I guess that when working with front panel express (it is pretty easy, I am just worried about making the holes the right dimension) I can find the mounting specs (hole size, spacing, etc) in the datasheet for the part I am looking to mount?

 

[MisterX]

Yep, the datasheet is where they usually hide that information but it never hurts to double check the parts with your calipers.

 

[haejuk]

What do people use for punching holes in the bottom of a case in order to mount the PCBs?  I am totally comfortable with soldering (not as much so with measuring, probably going to read around before I ask anything about that), but I am totally clueless on casework.  Is it prohibitively expensive to have Par-Metal punch all the holes I need when I order from them?
 
I haven't actually started my build yet due to budgetary setbacks, but I want to know how to do things so I know what tools I need. 

 

[cfcubed]

You should use search & try to find some build threads around here (not necessarily just for this project)... IIRC there are some good ones around, showing tools, techniques, etc.
 
I think many use a good hand drill or drill press (w/center-punch, masking tape) to make their PCB standoff holes, etc.  The expense of proper, fancy professional-looking casework (machined cases, FPE endplates, etc) is higher than doing those manually.  But it does take some skill, planning, tools & practice to get decent looking results using a raw case & manual "machining".
 
For warm/hot projects one thing that's hard to manage manually & have it come out nice is enclosure ventilation.  I had to resort to some greenlee punch hackery to get adequate ventilation in my budget 2-ch beta22 build:
 

 
Note: I've since asked the ebay seller of this case to offer one w/more top panel ventilation & he has - search "Metal Cabinet Project Box HB-350-1" - you could use one of those cases for the PS & one for the AMP box of a 2-ch build.  They're once example of a low-cost serviceable case if you wanted to try to go the manual route.   I'm planning to pick some of those cases up once I clear the decks of my in-progress projects

 

[jcx]

don't necessarily need holes for PCB mounting to chassis http://www.richco-inc.com/products/circuit-board-hardware/97-circuit-board-hardware-catalog.html?PartNum=&country=RICHCOUSA&grpcode=A1680
 
search: self adhesive pcb standoff

 

[jdkJake]

don't necessarily need holes for PCB mounting to chassis http://www.richco-inc.com/products/circuit-board-hardware/97-circuit-board-hardware-catalog.html?PartNum=&country=RICHCOUSA&grpcode=A1680

search: self adhesive pcb standoff

Nice concept. That much is for sure.

How does the adhesive stand up under prolonged exposure to heat? Or is that not an issue as it will generally be used on the underside of a board?

 

[haejuk]

I had seen those adhesive stand-offs before.  I am just not sure how well they will stand up to shipping, as I will be moving to the other side of the world in the foreseeable future.  My main concern is all the heatsinks on these boards may be too heavy if a case ends up sideways in a box or something.
 
cfcubed, thanks for the tips.  I will search around more and check out those enclosures.  I was thinking of going with Par-Metal 20 series as they already have more than adequate ventilation.  They are just a little large for a 2 channel build, but I can deal with that.

 

[haejuk]

If I use an aluminum case for my Sigma22 and one for my Beta22 with the B22 stacked on top of the S22, will an unshielded transformer cause any hum in my B22?  I have read that aluminum is a totally useless an as EMI shield.  I was going to stack 2 Par-Metal 20 series cases on top of eachother, even though they are way bigger than what I need for a 2 channel build.  Will I have problems without a shielded toroid?

 

[MrMajestic2]

Quote:

If I use an aluminum case for my Sigma22 and one for my Beta22 with the B22 stacked on top of the S22, will an unshielded transformer cause any hum in my B22?  I have read that aluminum is a totally useless an as EMI shield.  I was going to stack 2 Par-Metal 20 series cases on top of eachother, even though they are way bigger than what I need for a 2 channel build.  Will I have problems without a shielded toroid?

 
I've built one B22/S22 combo with four transformers in it and I didn't hear any hum.

 

[mechgamer123]

Can anyone answer my noobie question? How much would all of the parts for 3 boards cost?

 

[jcx]

I realize its hard for newcomers to judge but 3-channel really is a unfortunate local to head-fi fad - not technically justified - you can have an excellent amp with just 2 amp boards
 
http://www.glassjaraudio.com/product.sc?productId=5 is one kit source
 
for further cost savings you can buy open frame linear supplies pre-built for less than sigma22 kit prices, near the cost of new parts alone if you shop aggressively unless you find surplus/remaindered/used parts
 
 
the biggest step up in "quality" - in many of the parameters that are claimed to motivate "3-channel" construction - is "dual mono" - separate, isolated power supplies for each channel - but to get full advantage requires 4-pin "balanced" connectors/headphone cabling

 

[OJNeg]

Quote:

Can anyone answer my noobie question? How much would all of the parts for 3 boards cost?

 
I think you could get the beta22 boards (w/components) for ~$100 each. The sigma22 board (w/components) would cost another $100. Add in the step-down transformer, heatsinks, case, case components, internal wiring, power and transfer cables, and shipping and....I'm not sure where that leaves you. My educated guess would be <$500 if you're lucky. Can anyone give a more concrete number for a frugal-ish 2 channel build? I'm actually quite interested myself.
 
Quote:

I realize its hard for newcomers to judge but 3-channel really is a unfortunate local to head-fi fad - not technically justified - you can have an excellent amp with just 2 amp boards
 
http://www.glassjaraudio.com/product.sc?productId=5 is one kit source
 
for further cost savings you can buy open frame linear supplies pre-built for less than sigma22 kit prices, near the cost of new parts alone if you shop aggressively unless you find surplus/remaindered/used parts
 
 
the biggest step up in "quality" - in many of the parameters that are claimed to motivate "3-channel" construction - is "dual mono" - separate, isolated power supplies for each channel - but to get full advantage requires 4-pin "balanced" connectors/headphone cabling

 
Link? Or are they just out there?

 

[jcx]

 http://www.mouser.com/catalog/catalogusd/645/2174.pdf  [size=xx-small]HAA24-0.6-A+-G[/size] dual 24 V @0.4 A is a fine size for most headphones/2 board Beta22 - more V "needed" only for a few insensitive exotics

 

[haejuk]

I have all the parts for my boards, but before I start I am planning everything out so I don't end up with a mess on my hands.
So, I am back with a few questions about parts for the S22.  I would like some suggestions as to what are some attractive power switches that are rated up to 250V (I will be adding a voltage selector).
 
I have found this one on my own so far:
http://www.mouser.com/ProductDetail/Schurter/124166211120000/?qs=VO2%2fVXZcKR0q6Y2q9v1PLg%3d%3d
 
I was wondering if there are other good looking ones out there, preferably in black, rated for 250V.  Also, is this one safe to hook up to the power mains as a power switch?  Any suggestions would be helpful.
 
I also need suggestions for IEC power connectors (fuse?), and I found a voltage selector which should work with the transformer I have (series-parallel).  If anyone is interested, I plan to use this voltage selector:
http://www.mouser.com/ProductDetail/Schurter/00334504/?qs=j1qng3XoT%2fnBgzwr5nRvnQ%3d%3d
 
I found the connectors I will use for the umbilical cable on p. 103 of this thread, but don't know what cable to use for it.
 
Finding the proper parts for the B22 is much easier as I understand that end better.  But I would like some suggestions for internal wiring wire (especially sheilded wire to wire to the pot on the front).
 
Thanks as always.

 

[MrMajestic2]

Quote:

I have all the parts for my boards, but before I start I am planning everything out so I don't end up with a mess on my hands.
So, I am back with a few questions about parts for the S22.  I would like some suggestions as to what are some attractive power switches that are rated up to 250V (I will be adding a voltage selector).
 
I have found this one on my own so far:
http://www.mouser.com/ProductDetail/Schurter/124166211120000/?qs=VO2%2fVXZcKR0q6Y2q9v1PLg%3d%3d
 
I was wondering if there are other good looking ones out there, preferably in black, rated for 250V.  Also, is this one safe to hook up to the power mains as a power switch?  Any suggestions would be helpful.
 
I also need suggestions for IEC power connectors (fuse?), and I found a voltage selector which should work with the transformer I have (series-parallel).  If anyone is interested, I plan to use this voltage selector:
http://www.mouser.com/ProductDetail/Schurter/00334504/?qs=j1qng3XoT%2fnBgzwr5nRvnQ%3d%3d
 
I found the connectors I will use for the umbilical cable on p. 103 of this thread, but don't know what cable to use for it.
 
Finding the proper parts for the B22 is much easier as I understand that end better.  But I would like some suggestions for internal wiring wire (especially sheilded wire to wire to the pot on the front).
 
Thanks as always.

Do not use the switch in your link because its a momentary switch. You will cut the power as soon as you let go.