almost finished aleph3

[cowanrg]

with the help of a few forum members (magura, mikeW, and alain), i am nearing completion on my aleph3. you can see specs and some other things in this thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=34222

here are some pics from my horrible digital camera (takes worse pictures than some camera phones!)

(they arent huge pictures, but it still might take a few seconds to load)

view from front. its got a faceplate, but no light or on/off switch yet. still deciding what to do about all that.

An externally hosted image should be here but it was not working when we last tested it.

a view of the back, i use the speaker posts on the far sides becuase these are monoblocks and i have short speaker cables. this helps me with better placement. it looks like the bolt of the xformer is touching the plate that the pcb is on, but its got about a 1/2" of clearance, its just the camera.

An externally hosted image should be here but it was not working when we last tested it.

here is what it looks like all closed up. the case if from par-metal, and is really great. its cheap, and looks very nice. however, like all metal, it scratches easily, and is very difficult to work with when drilling, etc...


hopefully i can get it all wired up within the next few days and then start on the other one!

An externally hosted image should be here but it was not working when we last tested it.

 

[Brian Donaldson]

Put a thermometer in the case and check, but my money is on the amp frying itself with that little ventalation and fins oriented the way they are. I don't mean to step on any toes, and it may be OK, but take precautions until your comfortable with final temp.

 

[cowanrg]

i have tested them face down, and they are fine. they get a bit hot, but not horribly so. 2 small fans might work out well though. but its already been tested.

 

[cowanrg]

also, its hard to tell from the pictures, but the top, sides and bottom are ventilated...

 

[kilowattski]

Just a word of warning. You may get some unwanted 60 Hz stuff because your amp board is awful close to the power transformer.

 

[cowanrg]

i hoped to counteract this by having the pcb mounted on a 1/4" metal plate. you can kinda see it in the picture. ive tested it like this, and its dead silent.

 

[trigon]

i hoped to counteract this by having the pcb mounted on a 1/4" metal plate. you can kinda see it in the picture. ive tested it like this, and its dead silent.

If you keep your signal ground away from the power supply ground you should be ok. Nice Aleph.


Trigon

 

[BDP]

PAR- METALS case

Is the case a series 20? I'm looking for a case for the MOX X-over. How thick of front panel did you order and what type of finish, painted black or black anodized.

Thats going to make a nice package. How much bias on the outputs?

BDP

 

[cowanrg]

Re: PAR- METALS case

it is the series 20 case. its a bit thin, but its still metal, and strong enough for all the stuff in it. the front panel is the 0.25" thick panel. its decent, i wanted the thicker, but it wasnt in stock, and i got these for cheap. they are black anodized. i almost wish i would have gone with painted, because the anodizing scratches very easy, so its hard to get a PERFECT finished amp if you have any work that needs to be done on it.

i think the bias is normal, it pulls a bit over 2 amps. it gets HOT.

Is the case a series 20? I'm looking for a case for the MOX X-over. How thick of front panel did you order and what type of finish, painted black or black anodized.

Thats going to make a nice package. How much bias on the outputs?

BDP

 

[Magura]

When Working on painted/anodized ithems, just cover the ithem with adhesive plastic film for protection while machining. You can buy an easily removable version from the AD companies, they use it for window decoration.

Magura

 

[cowanrg]

yeah, i had some masking tape, but apparently not enough.

what is "AD companies"?

 

[Magura]

AD= Advertising and design

Magura

 

[cowanrg]

aaaaaaaaah.

hum, i dont know any of those. i do know of a few art places though. i guess any old sticky film stuff would probably work though. ill see what i can do.

how come you never emailed me back?

 

[Magura]

how come you never emailed me back?

Hmmm...cause I never got the mail??? Im still waiting for a mail with the dimensions required


Magura

 

[cowanrg]

oh ok. thats odd. well, i decided against the copper sheets. the PCB im using works just fine, i just needed to solder it a little bit better than before. its a good joint now, i think.

 

[jleaman]

They look really good.. Good job.. If any thing just put a small 12V fan in the bottom to suck in or out the air and run it at like 6V so it doesn't make any noise..

 

[Magura]

oh ok. thats odd. well, i decided against the copper sheets. the PCB im using works just fine, i just needed to solder it a little bit better than before. its a good joint now, i think.

As long as you got good connection between the PCB and the cap terminals, it should be just fine. The easy way to check if the joint is good or not is simply to check out if its getting hot.

Magura

 

[cowanrg]

Magura:

when i was soldering it was getting pretty hot at the PCB, so that should be good. sure enough though, at 2 points on the previous version, there were some black parts on the bottom, it had sparked and broken the bad solder joint.

JasonL:

yeah, i will test it out. Magura seems to think it will be perfecly fine, if not a little warm, but i might put in a small fan or two, running at half power.

 

[Magura]

Considering that when testing it last time the heatsinks were laying on a table with the finns facing down, and it still didnt get utterly hot, I guess there should be no heat problems.

Magura

 

[cowanrg]

its just hotter than ive ever been used to an amp getting...

but i think it should be fine. i just need to get it all finished and get it running. then i can start the second one, THEN, i can finish my aleph2's FINALLY.