Aleph J build guide for noobs

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#282
TungstenAudio said:
If the build documentation is to focus on a vertical mounting scheme for the transformers, then it needs to discuss how to avoid a shorted turn around the outside of the transformer. This is a real hazard. I actually use 5/16" or 3/8" Nylon mounting bolts for my transformers, or mount the transformers onto a slab of acrylic which is then bolted onto the baseplate.
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What exactly is a shorted turn and how does a nylon bolt avoid the problem?
Thanks.
Jazzzman
 
#283
jazzzman said:
What exactly is a shorted turn and how does a nylon bolt avoid the problem?
Thanks.
Jazzzman
Click to expand...


My understanding is that if you were to have a closed loop of wire that went through the hole of the torus- imagine a metal U-bolt going through the hole and bolted onto the metal chassis- you'd have a closed circuit in which a current would be induced by the transformer. A big no-no. One way around this is the Omega clamp: Omega-Bracket – Toroid which I got (very nice folks but shipping costs and arm and a leg unless you can do a local pick-up in MD).


A nylon bolt obviates this problem as it's non-conducting. Unless it's pretty beefy I wonder how it can be used to mount the toroid vertically.
 
#284
flohmann said:
I get that, but the question on my mind is what would most noobs want? I'm worried that poorly crimped connectors might be a significant point of failure, especially for those who have never used a crimper before? I guess if we use connectors with removable insulation sleeves, and insist on soldering along with crimping, that might be the best of both worlds.
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Yes, totally hear you on that. As soon as you add an option here, another option there, pretty soon you have the universal PS board. Perhaps simply a pointer to the thread on build tips to facilitate swapping Pass amp circuits would suffice...?



I'm trying to keep all of this in mind, and figure out what the "best practice" for wire routing is (if you'd like to take on gathering that from the various posts on the illustrated build guide thread, I'd be grateful!), but in the end some of the final trouble-shooting stuff will likely have to go to the illustrated build guide thread.
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Sure, I'd be willing to lend a hand. Something like gather up advice about dealing with noise/hum from a few threads? I'm slowly building up my parts and tools, and so haven't started in earnest.
 
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#285
Shorted turn - basically the transformer doesn't care if it's trying to conduct through wires around the core or metal mounting hardware - so the mount must be only on one side and nothing loop around the core in its entirety. Nylon, as mentioned, breaks the circuit.

The following photo shows what you don't want to do.

Toroidal_Transformer_Mounting_Fig7.jpg
 
#289
What female Faston connectors do people prefer for connecting bridges and amp boards to PSU board blade connectors? I'm seeing a dizzying array at Mouser, wondering if there's an easy choice? I'm assuming something that allows crimping AND soldering is better than crimp alone for reliability (esp in the hands of noobs like me who maybe have never used a crimper)?
 
#290
I usually just pick them up at the local hardware store or get a pile off of Amazon.

That's not really a part that I personally over-analyze. Pick the proper size for the wire gauge you're using to help ensure a good crimp. They are sometimes color-coded based on wire size. Common colors are red, blue, and yellow. It'll tell you the corresponding gauges in the specs. All can be soldered in addition to crimping if you want to remove some of the insulation or if you buy uninsulated connectors.
 
#293
ItsAllInMyHead said:
I usually just pick them up at the local hardware store or get a pile off of Amazon.

That's not really a part that I personally over-analyze. Pick the proper size for the wire gauge you're using to help ensure a good crimp. They are sometimes color-coded based on wire size. Common colors are red, blue, and yellow. It'll tell you the corresponding gauges in the specs. All can be soldered in addition to crimping if you want to remove some of the insulation or if you buy uninsulated connectors.
Click to expand...

I grab the by the connector end with old needle nose, hold it over a flame until it begins to melt, scrape plastic insulator off. Solder, use shrink wrap.

Russellc
 
#294
Did another search and found the fuse should be 2.5A 250V. Is that for one at a time, or both?

My back panel parts kit came with these:

F2AL250V - this one has dimples in both silver caps

and

GFE JET CQ 10A 250


If I need two, can I use two 3A 250 fuses? Can I use a 2.5A 250V and a 3A 250V?
 
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