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AU-999 Mystery components and power switch quesions

Great work DCinDC and Kev!!!

That screen shot of the before and after pretty much tells the story. Another 999 owner that will be trying out this modification shortly. :thmbsp::beerchug:

Cheers

John
 
SUWEET!

I went after a problem, and found a diamond!

TNKS for those graphs Kev, that's brilliant! That's 3 dB at 35 hz!

I would just jumper it, it's way easy, and there's a good chance to destroy the wafer switch terminal while trying to desolder the small coaxial wires from the speaker switch. I try to NOT solder on the AU-999s switches if I don't have to. Sansui put the original wires thru the loop a few times making a good physical connection and then soldered them. When trying to get them free from the terminal, even a skilled solderer can break the little terminal loop off. When I was changing some broken switches, I just swapped the lever from a good switch to the broken one to avoid soldering.

Just use a piece of cut lead from a new component installaion (I keep a little bowl of them) and tack solder it to one of the terminals, then solder the other terminal. Use hemostats or needlenose pliers, the wire gets hot being soldered!

The pic in my post above shows the two terminals to be jumpered.

Do we have a beer icon? :beer: YAY!
edit: we do!


edit: I redid the picture to make it easier to see. Pay no attention to the missing chassis mounted driver transistor in the pic. I used an old pic of this area of the amplifier.

attachment.php
 
Last edited:
tobyj17 said:
I'll definitely be doing this when i get home from work tonight! I probably won't eliminate, i'll just solder in a jumper. I'll also do a before and after comparison.. the kef's i have really like deep bass and i'll definitely be able to tell the difference...
Click to expand...

You will need to remove and connect the blue wires together without touching either of those two terminals, because they are connected to what we call a slope resistor, which gives the attenuation of the filter....
Or you could just snip those resistors off and then jump the connection, either way you must not be connectoed to those resistors, as they will attenuate the entire signal probably about 6db.


skippy124 said:
Great work DCinDC and Kev!!!

That screen shot of the before and after pretty much tells the story. Another 999 owner that will be trying out this modification shortly. :thmbsp::beerchug:

Cheers

John
Click to expand...

I will be keen to see what you think John, to me its a completely different amplifier now....

DCinDC said:
SUWEET!

I went after a problem, and found a diamond!

TNKS for those graphs Kev, that's brilliant! That's 3 dB at 35 hz!

I would just jumper it, it's way easy, and there's a good chance to destroy the wafer switch terminal while trying to desolder the small coaxial wires from the speaker switch. I try to NOT solder on the AU-999s switches if I don't have to. Sansui put the original wires thru the loop a few times making a good physical connection and then soldered them. When trying to get them free from the terminal, even a skilled solderer can break the little terminal loop off. When I was changing some broken switches, I just swapped the lever from a good switch to the broken one to avoid soldering.

Just use a piece of cut lead from a new component installaion (I keep a little bowl of them) and tack solder it to one of the terminals, then solder the other terminal. Use hemostats or needlenose pliers, the wire gets hot being soldered!

The pic in my post above shows the two terminals to be jumpered.

Do we have a beer icon? :beer: YAY!
edit: we do!


edit: I redid the picture to make it easier to see. Pay no attention to the missing chassis mounted driver transistor in the pic. I used an old pic of this area of the amplifier.

attachment.php
Click to expand...

Great teamwork on this one, thanks for the scoop DCinDC.....Cheers....:thmbsp:

Just to reiterate guys, you must not just jump that connection, because you need to also disconnect the slope resistors as well....

That little filter is actually a 6db per octave high pass filter.......
I have NO idea why Sansui put that in there, it seems completely ludicrous to me especially since there is already a switchable LOW cut filter which does that same thing......Bizzare at best.....
 
Other manufacturers have had this type of circuit built in from new, Quad 33 was one. Sounded much better when removed. I wonder if it was for their own protection? (No pun intended.)
 
bogle111 said:
Other manufacturers have had this type of circuit built in from new, Quad 33 was one. Sounded much better when removed. I wonder if it was for their own protection? (No pun intended.)
Click to expand...

I suspect as there wasnt a lot going on in the extreme low bass department when this amp was designed, rather than having the Woofers flopping around for no real musical benifit, they high passed to tighten everything up.....
 
Okay, so snip the two blue wires and attach them together? And don't allow them to touch anything? Sounds pretty simple..
 
Landrew said:
I did the jumper, was going to do the snip too but mine has three blue wires in each channel. :dunno:
Click to expand...

Can you take a picture and post......? We will be able to help....

If you trace one wire back, it will disappear into the front panel to the switch, and the other one will trace back to a pin on one of the blue molex connectors.....
 
Here's a pic of the one channel having three blue wires:
photobucket-11340-1343349342961.jpg

And here's the other side..already snipped:
photobucket-2619-1343349377179.jpg
 
tobyj17 said:
So.. on the side with the three blue wires, which ones do you splice together?
Click to expand...

OKay, the grey shielded wire on the left (looking at the picture) and its associated blue signal wire is one. (it should disappear up into the front panel).

Then the other grey shielded wire with its blue signal wire which is on the right and connects to the Blue Molex connector, it should have the blue signal wire attached to the very end terminal on the Molex connector.

So chop them off and take a pic so I can confirm they are the right ones....
 
The one that disappears into the front goes to the speaker selector switch..
photobucket-2759-1343351473818.jpg


photobucket-6683-1343351543954.jpg


Another goes to the Molex plug, and another wraps around the side and to the back.. can't see quite where that goes.
 
No left channel... apparently we got some mixed up wires here. No biggie.. I'll get them switched around. The right channel sounds pretty good though :D
 
tobyj17 said:
No left channel... apparently we got some mixed up wires here. No biggie.. I'll get them switched around. The right channel sounds pretty good though :D
Click to expand...

Oh bummer, The one on the right, which goes to the Molex connector on the end terminal is definitely the right one, so I must have seen it wrong coming from the right.....
 
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