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My Luxman Integrated has AC Inlet Envy

I love my Luxman 507ux, it does so many things right, so soon after I got it I built a shielded power cable as an upgrade to the relatively plain cable that came with it.

To make a long story short, after trying out a number of different cables and female IEC plugs it seems the AC inlet has prongs which seem too short. For sure, the Luxman has no ground pin. I'm sure that this means it's not required, so that’s not an issue. What is an issue is that even a Wattgate plug, which are famous for a tight grip, can’t stay in. Even a little wiggle can disconnect the amp.

It seems either or all of these are true:

  • The missing ground pin is keeping plugs from feeling very grippy
  • The pins are too short
  • The pins are too thin

If I play with a cheap power cord, it seems like the AC doesn’t connect unti lthe very last 2 mm of travel of the plug. This seems wrong.

I bought a cheap replacement inlet and it just feels so much better. Meaning, I can feel the plug grip the pins much earlier, and they all grip much better.

Anyone else have issues with Luxman inlets??

 

PS - I absolutely insist on building my own power cables. This is my hobby not yours so please stop trying to convince me my problem is that I didn’t buy your boutique brand.

 

erik_squires
erik_squires OP
15,861 posts
 

Wow, I'm so glad my old Audio Research SP8 preamp has a captive power cord.

We'd sure have a lot fewer discussions if everyone did this. 🤣

ghdprentice
6,464 posts
 

Yes, but inferior sound quality.

imhififan's avatar
imhififan
2,129 posts
 

The transformer may be 20 gauge but the fuse is 15A.

Interesting, 15A fuse for a 110Wx2 amplifier! No soft start circuit?

erik_squires OP
15,861 posts
 

@imhifiman

 

THe unit was too heavy for me to play and trace it back and forth between the bottom PCB and the top, but no. It looked like the main transformer plugged directly to the fuse. You can see it in the picture I took. There’s a service transformer for the standby circuit, then the inlet plug, then fuses and then a wider plug which I believe goes straight to the main transformer.

Also, going from the drop in line voltage when I turn this beastie on, no, there’s no soft-start.

The PCB markings below the fuse say 15A and that’s exactly what was in there.

Luxman may have produced 10s of thousands of these units, so they probably know their materials very well, but given how difficult a field replacement of those wires, and fuse sizing I would have 100% used thicker than 20 gauge.

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