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AU-X11 Repair attempt.

Looks like I'm going to have to notch or drill holes. Can't wire around the heat sinks. :(



I've been looking at this unit and it looks like I can drill 4 small holes between the fins of the heat sink where the wires are currently. I'm going to look for a grommets to put in the holes so it looks neat. To make this work all I need is a 1/4" opening :idea:
 
Rumnarv said:
Looks like I'm going to have to notch or drill holes. Can't wire around the heat sinks. :(

I've been looking at this unit and it looks like I can drill 4 small holes between the fins of the heat sink where the wires are currently. I'm going to look for a grommets to put in the holes so it looks neat. To make this work all I need is a 1/4" opening :idea:
Click to expand...

How was it wired before? or was it too messed up inside for you to see that?

I appreciate it can be a lot of work to re-wire.
 
Great save sir, btw many many of us know exactly what the 'wife approved volume threshold is' and have suffered the stare down consequences of excessive volume knob manipulation.
Its a stare down 'cause the lips move but we can't hear the comments :)
-Lee
 
Hyperion said:
How was it wired before? or was it too messed up inside for you to see that?

I appreciate it can be a lot of work to re-wire.
Click to expand...

The wires are for the TO3-P conversion. I wired around the heat sink because I didn't trust the legs of the outputs going through heat sink. My luck something would move shorting out the leg of the transistor to the heat sink.

You can see in this picture how the wires are run, they just loop over the bottom of the heat sink and connect to the bus bar on the back side. The problem I'm having is the heat sink sits flush to the bottom panel, with the wires routed over the bottom of the heat sink it won't allow me to install that cover.

I think I'm going to use a 19/64 drill bit and drill a hole for each wire set between the fins. That would be the easiest way. This unit is far from a good cosmetic example so I'm not all that worried about it as long as it functions 100%.

 
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Overundr1 said:
Great save sir, btw many many of us know exactly what the 'wife approved volume threshold is' and have suffered the stare down consequences of excessive volume knob manipulation.
Its a stare down 'cause the lips move but we can't hear the comments :)
-Lee
Click to expand...

Thanks! I know that look very well, it happens mostly when I crank ZZ Top or SRV. Don't know what her hang up is on those 2.
 
Rumnarv said:
The wires are for the TO3-P conversion. I wired around the heat sink because I didn't trust the legs of the outputs going through heat sink. My luck something would move shorting out the leg of the transistor to the heat sink.

You can see in this picture how the wires are run, they just loop over the bottom of the heat sink and connect to the bus bar on the back side. The problem I'm having is the heat sink sits flush to the bottom panel, with the wires routed over the bottom of the heat sink it won't allow me to install that cover.

I think I'm going to use a 19/64 drill bit and drill a hole for each wire set between the fins. That would be the easiest way. This unit is far from a good cosmetic example so I'm not all that worried about it as long as it functions 100%.
Click to expand...

Ok, fair enough, just making sure there was no other way. :thumbsup:
 
I'm guessing that if you add a bit of heat shielding to the wires you could use (or if need be expand) the unused small holes or a couple of the larger holes now occupied by the mounting screws?

Going through that copper would be a lot easier that through that very thick heat sink.

X1 Unsed Holes A

X1 Unsed Holes A

  • Media owner Ronito6
  • Date added
  • Comments 2

Small holes are 3.85mm diameter.
The larger mounting holes are 5.5mm diameter.

Seems the smaller holes (1 for each transistor) may serve.
 
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That would work also. I would still need to open up the holes with a drill bit. I've got a drill press and some nice cobalt bits that would make quick work of it regardless of where I drill it.
 
Since the X1 restorations have gone dark in extended listening testing.

I was wondering if this X11 ever saw completion since the last posting about it here on December 20, 2015.

Any updates on this project? :bye:
 
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Rumnarv said:
When setting the DC offset and bias current adjustment, I started off using the specs for an AUX-1 because there isn't an AUX-11 manual anywhere and things seem to work well. Pictures are pre-adjustment. The bias spec is 25mv +or-1. These settings seem to be working fine.
Click to expand...

I think the AU-X1 uses 0.47 Ohm emitter resistors on the power transistors, whereas the AU-XII has 0.22 Ohm emitter resistors (or at least mine does, and they look factory installed), so you may have set your bias current 2x higher than intended.

BTW, I'm really drooling over your work on the output mounting. Outstanding work!

Edit: schematic shows 0.33Ohm emitter resistors for AU-X1, but I know most units I see on this forum have 0.47Ohm installed.
 
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