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Old 5th July 2005, 03:53 PM   #11
steenoe is offline steenoe  Denmark
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Quote:
You have beside a seeminly good channel so it should not be that dificult
Yep, you are right, Tony. Uhhh, this amp is fairly packed and not easy to make some measurements on. I hardly dare to stick in the testprobes. The q's are sitting darn close on the driver board, they are also quite longlegged (wich is nice on girls, not on q's ) I guess I just have to give it a shot. I really like this amp, as I said, it's built like a tank, and is really a beauty.

Steen
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Old 5th July 2005, 04:18 PM   #12
steenoe is offline steenoe  Denmark
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Could you post a pic of the inside?
Yes, I can. Tomorrow, propably! You are gonna drewl It smells like NP had his hands in there!! I did read the manual, and it says that all components are matched! The amp runs with no NFB too. I guess it would be a bit reckless to just replace one component,then.
I will post a nice set of pic's of this amp

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Hope that at least gave a bit of input to the subject.
Thanks a lot, DUO.

I am happy you guy's are with me, on this one

Steen
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Old 5th July 2005, 05:22 PM   #13
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Originally posted by steenoe
You are gonna drewl It smells like NP had his hands in there!!

Gonna love seeing those pics!!!

That's what I also thought that it might be packed inside. It won’t be a good idea to take readings then. Start disassembling


DUO might have the clue, it may be oscillating. Cleen the input jacks with cramolin or something similar. Or change input jacks...resolder.... Check those signal cables/wire. Seems a good way to start.
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Old 5th July 2005, 05:37 PM   #14
steenoe is offline steenoe  Denmark
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DUO might have the clue, it may be oscillating. Cleen the input jacks with cramolin or something similar. Or change input jacks...resolder.... Check those signal cables/wire. Seems a good way to start.
Very good, Tony I will do just that! Yeah, oscillating might be it! I have just arranged that I will pick up the amp tomorrow I sure will post some pic's of this amp
I saw it yesterday, with no lid on, I was amazed Didnt dare to bring it home though, but if you guy's back me up, I am confident Man, that amp looks good What a set of output devices 24 per channel! I dont know if you noticed, but I fell in love

Steen
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Old 5th July 2005, 05:43 PM   #15
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Does it work with and w/o FB?

If so, look for the switch and change it.

The 5K bias pot might also be a source for oscillations, me think so. Moving it just a bit to both sides could kleen it, if you dare

I would also look at the thermal breaker. Check bypassing it.

Near the bias pot is a circle marked T 1V, any clue to what it is?
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Old 5th July 2005, 05:50 PM   #16
steenoe is offline steenoe  Denmark
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If so, look for the switch and change it.
I dont think there is any switch! The hole topology is NFB! At least that is what I gathered from the manual. Also, I did notice that there was a Thermistor That doesnt excactly make it easier on measuring?? You just cant keep turning this thing on and off??

Steen
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Old 5th July 2005, 05:53 PM   #17
steenoe is offline steenoe  Denmark
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The 5K bias pot might also be a source for oscillations, me think so. Moving it just a bit to both sides could cleen it, if you dare
Yep, I do dare! That was my first thought!! Give it some massage

Steen
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Old 5th July 2005, 05:56 PM   #18
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Ok, so the T 1V is a thermistor.
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Old 5th July 2005, 06:17 PM   #19
steenoe is offline steenoe  Denmark
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Ok, so the T 1V is a thermistor.
I have studied the schematic posted earlier on, cant see T 1V!! I did spot the thermistor in the amp, though! It was sitting right there at the power inlet!

Steen

I do see T1v now, have no idea what it is!!
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Old 6th July 2005, 05:36 PM   #20
docjoe is offline docjoe  Europe
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Hi Stinoe

here are threads where this has been dicussed allready...
stasis 2 and 3 schematics

Stasis 3 Power Transistors

Threshold S300 output transistors help

I have a Stasis 2 sitting on my bench, with same oscillation problems:

Change the bias adjust pot for a multiturn one
I changed the drivers for MJE 15030/15031
Changed all the TO3s for MJ 15024/15025
the thermistor is 1K

Change ALL the capacitors, especially the tantalum 0.1 and 4.7 Uf they often cause problems, anyway in such a warm environment they get Roasted after some 20+years....


Open the sides and you'll get plenty of place to work

For testing, do not unsolder the input wires from the back panel, and do not unsolder the tiny grey wires that come from the star earth under the square ground plane and attaches to the negative cinch pin. if not you loose the ground return for the input section and you'll light all the leds

check for output offset and set bias at about 0.7 to 0.8 A
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