2. tech-talk
  3. 183709-20253

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
16,128 posts
 

PS -

I’ve done some totally not scientific testing of the contact overlap. Using a multimeter and shorting out the plug I’ve determined that from the point that the plug reaches minimum resistance to the fully seated position is 5 mm. That is, you have to pull the plug out 5 mm before the resistance would rise above zero. That’s a lot better than what I’m experiencing on the Luxman which seems to disconnect at 1-2 mm.

erik_squires OP
16,128 posts
 

PPS -
 

Yeah, I'll use a 3 pin plug, and add a little heat shrink on the inside so it looks purty.

ditusa's avatar
ditusa
1,887 posts
 

@erik_squires;

Remember IEC 14 inlet see below:

Mike

https://www.schurter.com/en/datasheet/6100-3

erik_squires OP
16,128 posts
 

@ditusa

As a matter of fact, what I ordered wasa not a C14 but a C16 inlet. The only difference I can tell is that the C16 inlet has a plastic ridge under the ground pin.

If you notice a lot of DIY male plugs have a little ridge cut out under the ground pin. That’s to mate with the C16.

I’m not sure if there’s any practical benefit to the ridge in a C16 inlet except to ensure a straight fit. Based on this chart, the only difference I can see is the maximum pin temperature, which I hope never actually gets near 70C:

 

https://www.webberelectronics.com/info/iec-chart

ditusa's avatar
ditusa
1,887 posts
 

@erik_squires Wrote:

As a matter of fact, what I ordered wasa not a C14 but a C16 inlet. The only difference I can tell is that the C16 inlet has a plastic ridge under the ground pin.

I agree, I think your Luxman originally has a C-17 C-18 two prong plug.

Mike

More to discover