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Are these MOSFET's ?

Bigears

Manager of my own day
I was doing the rebuild on my Luxman RX 101 suckface.This reciever sounds wonderful and has the smooth bottom end like a tube amp. Now to fix the suckface mechanism.
 

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Thanks for the post CC, but could you elaborate? I don't know what pnp is and any additional info you could post about this particular output set would be helpful to me.
 
No these are no Mosfets, only normal bipolar transistors.
So if it sounds wonderful, what do you want to do? There is no need to fix things which ain't broke!
 
agger said:
No these are no Mosfets, only normal bipolar transistors.
So if it sounds wonderful, what do you want to do? There is no need to fix things which ain't broke!

agger, thanks for the info. While it sounds wonderful, it is a suckface Luxman with an inop suckface! My main reason for adding this unit to my collection is because of the retractable face, which needs to function. To remove the suckface mechanism for repair, much of the outer panels need to be removed, that is when I came upon the transistors. The nice warm sound this unit produces has been talked about before on AK, but I was still surprised at how good it sounded for 40 wpc. I checked the DC offset and it was about 15 mV and none of the caps appear to be leaking or bloated, so I will leave it as is.

The suckface has been completely removed, cleaned, lubed and a new belt was sourced. I only have to reinstall the drive back into the chassis. I have full picture documentation of this rebuild, should anyone be interested.

It is simply amazing that Luxman spent the resources on this worthless feature. The engineering and cost that went into this feature is hard to believe...
 
Okay, I couldn't resist, here are some pics of the suckface mechanisim. We have the Magura slot car motor with belt pulley and slipping belt, planetary gearset (like a damn overdrive from a car auto transmission!) and beauty shot of the whole mess.

I have a good source for the belt and more shots if anyone finds they have lost their way during the repair. Oh yeah, to change the belt the entire assembly has to be taken apart.
 

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Do a search on google of the numbers stamped on the device and you should find data sheets for it.
 
I've heard that Luxman used both a belt drive and a gear drive but from what I've seen, they are all belt drive. I think the confusion occurs if you don't dig into them, they appear to be gear drive.

Incredible engineering and added expense for what amounts to a worthless feature. I’m sure all RX series use the same mechanism. They had to recover their tooling expenses with a decent production run.

I'd love to find the advertising literature from back in the day to hear how they positioned this feature. I can imagine going into a high end audio store and having the salesman demo the suckface while looking at all the other high end components and wondering why. Thankfully, it’s a wonderful sounding unit and the retractable face only adds to the allure for me.
 
Luxman RX-101

I got two RX-101, that a store was selling as broken for $10.00 each. Their intend was that you could make one good one out of two broken one. Well, I did the repairs on both units. So, I now have two RX-101,s When I first lsiten to them, I was very surprise how good this 40 watter sounded. I must had gone thru more then 100 old SS transistor receivers and amplifiers during my 30 years of playing with audio stuff. But this Luxman was really good sounding. I think most people including myself throught that because of the gimmicky syck-face that it can not possibly sound very good. Well, I was wrong. They do sound pretty good. Better then most of the others that I had played with. I also got the Luxman R-1050, and the L85v amplifier.
 
I am in the process of doing this repair as we speak. If you could forward me your documentation it would be great help. Thank you.
 
If the number printed on the device has a prefix of K or J its a FET of some kind.. a prefix of A,B,C,D is a bipolar transistor A & B being PNP and C & D being NPN.
 
Okay, I couldn't resist, here are some pics of the suckface mechanisim. We have the Magura slot car motor with belt pulley and slipping belt, planetary gearset (like a damn overdrive from a car auto transmission!) and beauty shot of the whole mess.

I have a good source for the belt and more shots if anyone finds they have lost their way during the repair. Oh yeah, to change the belt the entire assembly has to be taken apart.

Gads!!! Why did they hide a belt in there and place gears outside?? Wouldn't it be better to have gears in the belt box as well??

Methinks I'll be sending my 101 back to the seller. I can't hear/feel the motor run when I power it on, and I need something this intricate and delicate like a hole in the head:thmbsp:
A pity too, as it seems to be a nice unit otherwise.
 
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