Hi, I have copied my original message from the parts section here, I figure it's best off seeing as it's a PSU question.
My new phono pre has a hum issue. It is seriously helped by moving the board away from the R core transformer I installed in it.
Unfortunately I dont have enough room in the box to get it far enough to not cause trouble, so I'm thinking of putting it in a seperate enclosure.
I therefore need to bring 5 wires from the transformer box, to the preamp:
- 2 for 230VAC
- 2 for 14VAC
- 1 for gnd
What sort of cables and connectors do you use when faced with this kind of situation ?
Cheers
My new phono pre has a hum issue. It is seriously helped by moving the board away from the R core transformer I installed in it.
Unfortunately I dont have enough room in the box to get it far enough to not cause trouble, so I'm thinking of putting it in a seperate enclosure.
I therefore need to bring 5 wires from the transformer box, to the preamp:
- 2 for 230VAC
- 2 for 14VAC
- 1 for gnd
What sort of cables and connectors do you use when faced with this kind of situation ?
Cheers
It´s not easy because you carry live voltages, connectors must be safe, meaning active voltage must go to female jacks so there´s no way to touch or short them, load goes to male pins, "safe" because if unconnected there´s no voltage on them.
I use machinery/industrial type connectors, they are available in lots of configurations: male - female - chassis mount - cable mount -any amount of pins,from 2 to 30 or more.
They are usually known as Cinch or Jones connectors, although AMP and certainly more brands make them.
Not your typical Audiophile product, they belong in a workshop or factory rather than in a living room, buy will do what you want.
Large component suppliers such as Mouser carry them.
As of wiring, maybe you can get a multi wire one, or make your own harness, joining many wires inside a plastic sleeve, even heatshrink if you wish.
Some examples:
You may use two sets if needed, to always have active voltage on female parts and passive loads on male pins, for safety.
I use machinery/industrial type connectors, they are available in lots of configurations: male - female - chassis mount - cable mount -any amount of pins,from 2 to 30 or more.
They are usually known as Cinch or Jones connectors, although AMP and certainly more brands make them.
Not your typical Audiophile product, they belong in a workshop or factory rather than in a living room, buy will do what you want.
Large component suppliers such as Mouser carry them.
As of wiring, maybe you can get a multi wire one, or make your own harness, joining many wires inside a plastic sleeve, even heatshrink if you wish.
Some examples:
You may use two sets if needed, to always have active voltage on female parts and passive loads on male pins, for safety.
Thanks for the advice.
Do you think this kind of thing would do the trick ?
https://www.audiophonics.fr/33488-t...-verrouillable-plaque-argent-300v-5a-o5mm.jpg
They are rated 300V 5A according to the specs. As far as 5 conductor wire is concerned, anything I can find that is readily available is either suited to signal transmission, or is massive .
I suppose wires and heatshrink would do, though possibly not very aesthetic
Do you think this kind of thing would do the trick ?
https://www.audiophonics.fr/33488-t...-verrouillable-plaque-argent-300v-5a-o5mm.jpg
They are rated 300V 5A according to the specs. As far as 5 conductor wire is concerned, anything I can find that is readily available is either suited to signal transmission, or is massive .
I suppose wires and heatshrink would do, though possibly not very aesthetic
These are called GX Aviation Connectors and there is a whole range of connectors of different sizes and number of contacts.
http://www.renhotecpro.com/wp-content/uploads/2017/04/GX-Series-Aviation-Connectors-Presentation.pdf
They are useful for low power connections because the plugs have a screw-on ring which prevents accidental disconnection and good cable grips in the plugs, so they make good secure connections which cannot be confused with any connections on the audio side.
However, personally I would be very hesitant to have 250V and 14V lines in the same connectors. Perhaps you should consider something like GX12-3 (3 pins) connectors for the 14V line and a completely separate GX16-3 system for the 230V line. (GX16-3 is rated at 7A/250VAC RMS.)
Use mains rated connectors for mains, these will always be shrouded pin (no possibility of touching a live part). Those unshrouded blade connectors are unsuitable and could even kill in a domestic environment with prying little fingers.
Keep Live & low power connections separated. Install Powercon for Live & an aviation for low power. What happens if one Live wire gets disconnected somehow and makes contact with the shell or with the low power pins ? Or better, move the power input to the trafo box and send only a low voltage signal to control a relay for power on.
I'd personally use a strain relieved mains cable out the back of the transformer chassis to carry the 240v. Chop up a figure8 or IEC lead and hard wire, then you can mount a cheap matching socket on the pre.
That maintains mains voltage safety and isolation, and allows you to plug in with a normal lead if you were to change your design or setup later.
That maintains mains voltage safety and isolation, and allows you to plug in with a normal lead if you were to change your design or setup later.
Sorry, I've forgotten the standard IEC connector since most of my PA speakers all use Powercons. My appologies.
You only have 5 leads and they are all AC so no worries about hum induction. For the umbilical I'd get some 16 gauge 5 wire mains cord as used with portable power tools. It has nice round rubber jacket. Clamp that to a female aircraft connector one with big fat pins 5 of them spaced as far as you can find, maybe a 25 mm 5 pin unit. Or the 5 pin Cinch above, but those require a square hole, aircraft connector has round hole which is always easier. Solder wire the other end to the transformer box use a strain relief to hold the cord from pulling out.
Oh and tie a knot in the cord so it can't be pulled out, old school.
16/5 SOOW Cable • Cut by the Foot | Wire & Cable Your Way
Oh and tie a knot in the cord so it can't be pulled out, old school.
16/5 SOOW Cable • Cut by the Foot | Wire & Cable Your Way
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Thanks to all for your replies.
Seeing as I already have an IEC mains socket installed in the preamp enclosure, I could use it for the 230VAC coming from the transformer + gnd and then use a 2 pin aviation connector for the 14VAC
My only concern is that someone (me inculded) might use that IEC socket and plug it strait into the wall ... It is highly unlikely but still possible.
Two seperate 2 and 3 pin aviation plugs may well be the way to go. The female part is the one that goes on the lead so it is safe as far as fingers are concerned
Seeing as I already have an IEC mains socket installed in the preamp enclosure, I could use it for the 230VAC coming from the transformer + gnd and then use a 2 pin aviation connector for the 14VAC
My only concern is that someone (me inculded) might use that IEC socket and plug it strait into the wall ... It is highly unlikely but still possible.
Two seperate 2 and 3 pin aviation plugs may well be the way to go. The female part is the one that goes on the lead so it is safe as far as fingers are concerned