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
corelli
997 posts
 

My Marantz Ruby has no ground on the IEC C-14 like yours.  I have quit using Wattgates as their IEC plugs have a bad design as you have found out. Try these instead--much better pin geometry:

https://www.amazon.com/gp/product/B08332R442/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

I plan on replacing the two pin IEC C-14 with a three pin.  Easy to swap out.  Just leave the ground unconnected.

tinear123
241 posts
 

It's rather easy to resolve.  I wouldn't modify the Lux except to ever so slightly bend the pins inward 2-3mm.  Then take the end of the cord that plugs into the Lux and shave the end back to bring the mating contracts closer to the end.  A belt sander makes short work of this but can be done by other methods.  I did this on a MoodWright years ago and completely resolved the connection issue.

petg60
1,486 posts
 

A simple way is to find a Furutech dealer and try there how tight is the fit between their inlets and iec plugs. That means probably you would have to change the iec inlet on your Luxman.

brianh61
82 posts
 

My 505UXII has had no issues with cables from Pangea, Shunyata, Cullen, or PS Audio.

erik_squires OP
16,128 posts
 

Thanks @Ryder I guess it’s possible my particular unit, the original UX, not UX II version of the 507, got a bad inlet.

It has no ground pin, so locking plugs are useless, and even if they are, the short contact distance between the plug and inlet has to change.

I am going to change this inlet. I have one from Mouser (3 pin) I can use right now or I can order a Fancy Furutech from Parts Connexion.

I just think it’s weird I’m the only one who had this problem.

It seems many who reply are missing the part about SHORT CONTACT DISTANCE. Let me try to draw this out:

=== Luxman IEC inlet

....========= Plug

====== Cheap Mouser IEC Inlet

 

In the diagram above you see the Mouser sourced inlet has much more overlap with the plug contacts. Gluing the plug or bending the contacts inwards doesn’t increase the contact distance.

This is not your normal loose plug problem. :) Again, imagine you go to plug in your coffee maker and notice the pins are half as long as they should be.  I might be able to keep it attached to the wall by tape or bending the pins but neither really solves the contact area problem.

 

More to discover