Sigma 22 wiring help
Dec 2, 2008 at 3:32 AM Thread Starter Post #1 of 15

Navyblue

Headphoneus Supremus
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I ordered an Avel Lindberg YS23 transformers with dual 30V secondaries to feed a Sigma 22 board.

If I connect the 2 secondaries in series, would it be effectively 60VCT?

If this would work, would there be any side effect such as on heat emission or efficiency?

I'd prefer having 3 instead of 4 wires going out of the transformer to the board.

Thanks.
smily_headphones1.gif
 
Dec 2, 2008 at 4:17 AM Post #2 of 15
Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif
I ordered an Avel Lindberg YS23 transformers with dual 30V secondaries to feed a Sigma 22 board.

If I connect the 2 secondaries in series, would it be effectively 60VCT?



From end to end, yes.

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif
If this would work, would there be any side effect such as on heat emission or efficiency?

I'd prefer having 3 instead of 4 wires going out of the transformer to the board.

Thanks.
smily_headphones1.gif



The one lead you would wind up with as the centertap (where you connect the secondaries together, or ground on the sigma board) has to carry the return current from both V+ and V- back to the transformer. Depending upon the loading of the sigma, are you sure you want to do this? Two wires in my opinion would be better, particularly if they are all the same gauge.
 
Dec 2, 2008 at 5:26 AM Post #3 of 15
The transformer is 80 VA, the amp would not be used to drive speakers, only as a pre amp and a headphone amp.

The cable that I'll be using to connect the transformer to the board is a 3 conductors shielded Belden that is used for mains power cord, I think it's at least 20 ga (I'll check the model and specs when I'm home).

Does it sound like it will be a problem?

If cable is up to the task, is there any other downside?
 
Dec 2, 2008 at 7:51 AM Post #4 of 15
No real downside for the β22 in 3-ch active ground or 4-ch balanced configs, because there will be very little ground current returning to the transformer center tap.
 
Dec 2, 2008 at 6:23 PM Post #9 of 15
Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif
Not only that, my dinner menu is often dictated by what is in the fridge too.
smily_headphones1.gif



Yes, that is a completely parallel situation.
rolleyes.gif


More correctly you should have said - I often substitute whatever I have in the fridge regardless of what the recipe calls for. But really the lesson here is that you're going to do whatever you want so I'm done trying to help.
 
Dec 2, 2008 at 6:30 PM Post #10 of 15
might as well just do a 2 channel, and put the sigma22 between the 2 channels. Rotate the b22 channels so the heatsink is on the outer edges.

If case size is *that* important, you're better off doing less than more.
 
Dec 3, 2008 at 1:24 AM Post #12 of 15
Quote:

Originally Posted by n_maher /img/forum/go_quote.gif
Yes, that is a completely parallel situation.
rolleyes.gif


More correctly you should have said - I often substitute whatever I have in the fridge regardless of what the recipe calls for. But really the lesson here is that you're going to do whatever you want so I'm done trying to help.



Don't get me wrong, I always appreciated your inputs.
smily_headphones1.gif


By looking at the power demand and what the transformer can put out, there can not be more than 3A of current flowing per conductor. Given that the cable is meant for carrying mains power it should manage that amount of current just fine.
 
Dec 3, 2008 at 1:33 AM Post #14 of 15
Quote:

Originally Posted by holland /img/forum/go_quote.gif
might as well just do a 2 channel, and put the sigma22 between the 2 channels. Rotate the b22 channels so the heatsink is on the outer edges.

If case size is *that* important, you're better off doing less than more.



That is certainly possible, and might be worth exploring further along that line of thought. But for now, I'm not giving up yet. I can even kick the S22 out of the enclosure and redraw the master plan if it is absolutely necessary.
 
Dec 3, 2008 at 3:22 AM Post #15 of 15
Quote:

Originally Posted by royewest /img/forum/go_quote.gif
Sorry to go slightly OT, but where did you order the Avel toroid?

Thanks,

__Roy



Avel sells direct. PartsExpress carries some, and I think I read of one person who said they will do special orders and are actually cheaper than going direct.
 

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