Roll Call: Who's building, built, or thinking of building a beta22?

[mb3k]

Quote:

Originally Posted by thrice /img/forum/go_quote.gif On second glance...are your diodes on correctly...perhaps it's just the light playing tricks,but they may be reversed.

Yeah, it looks as though you have your diodes the wrong way. Looking from the front (side closest to the LED) the diodes should all be facing toward you (metal tabs facing the back where the AC comes in).

EDIT:
See AMB's post #187

 

[amb]

el_matt0, your four rectifier diodes do indeed look to be installed backwards. The front side (with the printed labels) should face the center of the board. Compare against the assembled board pic at the σ22 website.

 

[n_maher]

Yup, confirmed on the full sized pics, rectifiers are in bassakwards.

 

[el_matt0]

! GUYS thank you, silly me im going to fix that right away and hopefully things should actually work! out of curiousity, does a trafo make any perceptible noise when "working and on"? ill keep you all posted on results..thanks again everyone for all the help, knowing me im sure youll all get another opportunity to before this beast is actually up and working

!

 

[n_maher]

The trafo might hum slightly, but it'll also hum pretty loudly (at least some have) if you hook it up incorrectly and short something that doesn't want to be shorted.

 

[thrice]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif The trafo might hum slightly, but it'll also hum pretty loudly (at least some have) if you hook it up incorrectly and short something that doesn't want to be shorted.

Something might blow up too...then you know something's wrong...caps popping is.....exciting.

 

[amb]

mb3k, for the Avel-Lindberg Y23 transformers, the secondary windings should be connected to the board in the following order:
~ G G ~ = yellow-orange-red-black (either left to right or right to left, it doesn't matter).

 

[el_matt0]

urgh, i absolutely dread unsoldering and resoldering thru hole components. i find desoldering braid to be for all intensive purposes, fairly useless, and often times accessing the top side with the iron so that you can place a desoldering pump on the underside is very difficult to do. tips/pointers/tricks?

 

[thrice]

Quote:

Originally Posted by el_matt0 /img/forum/go_quote.gif urgh, i absolutely dread unsoldering and resoldering thru hole components. i find desoldering braid to be for all intensive purposes, fairly useless, and often times accessing the top side with the iron so that you can place a desoldering pump on the underside is very difficult to do. tips/pointers/tricks?

You know I actually find desoldering braid easier than the pumps. Just get your iron a little hotter and lay a piece of the braid flat against the solder joint.

You might want to pull up a littte as you heat the solder joint (not much might you, you don't want to rip off traces...but just a little once the solder has melted.

Get some PCB board from Radioshack and practice....it helps.

 

[amb]

el_matt0, another comment -- your power transformer looms rather close to your amp boards on the left side. There has been plenty of discussion at the headwize β22 thread about how this causes hum and noise... Have you read them?

 

[el_matt0]

yea i was planning on installed a divider or something of the sort with some sort of insulating covering...that should help shouldnt it?

 

[Clutz]

THe problem with desoldering braid is that if your soldering iron is only minimally hot enough to get the job done, it'll have a hard time getting the solder braid hot (and keeping it hot - it's a pretty effective heatsink) enough to melt the solder. I have a crappy 40 watt soldering iron that I use when my 25 watt soldering iron isn't up to snuff for the desoldering.

 

[amb]

Quote:

Originally Posted by el_matt0 /img/forum/go_quote.gif yea i was planning on installed a divider or something of the sort with some sort of insulating covering...that should help shouldnt it?

A divider won't be good enough because the magnetic field from the transformer radiates and curves around. Again, please take the time to read the headwize thread (both part1 and part2), especially n_maher's posts which show what he had to do to tame the hum.

 

[n_maher]

Quote:

Originally Posted by el_matt0 /img/forum/go_quote.gif yea i was planning on installed a divider or something of the sort with some sort of insulating covering...that should help shouldnt it?

Help, maybe. Solve the issue, no.

 

[thrice]

Quote:

Originally Posted by el_matt0 /img/forum/go_quote.gif yea i was planning on installed a divider or something of the sort with some sort of insulating covering...that should help shouldnt it?

Quote:

Originally Posted by amb /img/forum/go_quote.gif A divider won't be good enough because the magnetic field from the transformer radiates and curves around. Again, please take the time to read the headwize thread (both part1 and part2), especially n_maher's posts which show what he had to do to tame the hum.

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif Help, maybe. Solve the issue, no.

Perhaps if you put the transfo outside of the amp case in a smaller enclsure....you could then run an umbilical to the amp. The hum issue was well documented in the aforementioned Headwize threads...I would also encourage you to read them. Placing a transformer in the same case as the amp boards tends to yield humming issues.... it's best to separate the PS and the amp, or at the very least the amp and the transfo.