Wire Organization inside an amp chassis

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ViperDoc
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Wire Organization inside an amp chassis

Post by ViperDoc »

I just finished wiring up my JTM45 last night and will test it this weekend. I wanted to ask how you all generally manage your wire paths inside your chassis. I generally try to bank wires off of the chassis floor and border based on information about noise I’ve read previously. The wires headed to the can caps I decided to keep airborne because of all the other traffic. Is there a better way to manage all of this stuff? I used 20 gauge Tube Depot solid, cloth-bonded PVC wire for this build. It strips really nicely, but is much larger in diameter.

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xtian
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Re: Wire Organization inside an amp chassis

Post by xtian »

We call general "wire organization" and layout "lead dress." And yours looks very good!

Floating wires in the air for short runs is fine. I have had trouble with wires lying against the chassis before, especially in combo builds, sometimes the wire will rattle against the chassis--some hot glue can solve this. But a more mysterious problem (years ago, so I don't remember all the details) was a wire was causing audible crackling because of proximity to the chassis--might have been stray capacitance, maybe type of wire jacket, I don't know, but problem was solved by pulling wire away from chassis.
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ViperDoc
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Re: Wire Organization inside an amp chassis

Post by ViperDoc »

xtian wrote: Thu Jan 16, 2020 10:54 pm We call general "wire organization" and layout "lead dress." And yours looks very good!

Floating wires in the air for short runs is fine. I have had trouble with wires lying against the chassis before, especially in combo builds, sometimes the wire will rattle against the chassis--some hot glue can solve this. But a more mysterious problem (years ago, so I don't remember all the details) was a wire was causing audible crackling because of proximity to the chassis--might have been stray capacitance, maybe type of wire jacket, I don't know, but problem was solved by pulling wire away from chassis.
Very good, xtian, thank you! Very good to know my wire soup isn't too far from the mark. I'll keep trying to do better, though! Still more amps in the pipeline.
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pdf64
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Re: Wire Organization inside an amp chassis

Post by pdf64 »

The use of a wire guage somewhat heavier than necessary is surely making things harder than they need be? Very tidy, especially considering that.
I don't see any issue running wires close to the chassis; after all, it is a screen.

Note that the wire from the CT of the HT winding is the noisiest of an amp, as it carries large current spikes required to charge the reservoir cap; hence it should connect directly to the -ve terminal of the reservoir cap, and be kept well away from sensitive circuits. Avoid making seperate connections of these to a common 0V point / star ground, as the current spikes may contaminate other circuits also connected to that common point.
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ViperDoc
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Re: Wire Organization inside an amp chassis

Post by ViperDoc »

pdf64 wrote: Fri Jan 17, 2020 12:08 am The use of a wire guage somewhat heavier than necessary is surely making things harder than they need be? Very tidy, especially considering that.
I don't see any issue running wires close to the chassis; after all, it is a screen.

Note that the wire from the CT of the HT winding is the noisiest of an amp, as it carries large current spikes required to charge the reservoir cap; hence it should connect directly to the -ve terminal of the reservoir cap, and be kept well away from sensitive circuits. Avoid making seperate connections of these to a common 0V point / star ground, as the current spikes may contaminate other circuits also connected to that common point.
Thanks, pdf64! I went all in on said wire a while ago and am plowing through my supply. I can definitely see how stranded PVC wire without the cloth bond would be much easier to deal with. On the positive side, it definitely stays where you put it once soldered. I noticed an option for aerospace grade wire with a much thinner, higher temperature pvc-like covering that was about 4x the cost but much more slender. What do you all like/prefer to use? I’m definitely a turret board guy, with that in mind.

Regarding your descriptions of sensitive circuits, that’s way over my head at the moment. Center tap of the high tension winding? I’ll look into that, but I’m not sure how to ID which circuits to keep it away from. Thanks!
Last edited by ViperDoc on Fri Jan 17, 2020 2:10 am, edited 1 time in total.
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thetragichero
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Re: Wire Organization inside an amp chassis

Post by thetragichero »

i use wire salvaged from organ power supplies.
i prefer the higher gauge because, as mentioned, it stays where you solder it. I'm not afraid of it snapping off like thinner wires i would use for stomp boxes
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