Short Stasis 3 question about DC leak

[ArneRo]

Have one of these babies and I have upgraded it once in the mid 90's. Now I have DC on the left channel about 78 mV. Is this acceptable or should it be fixed?

 

[Nelson Pass]

Personally, I don't get too excited about DC less than 100 mV.

There are no offset adjustments.

It is possible to trim various resistor values to minimize the offset, but this
is only recommended for the experienced.

The schematic is attached.

 

[Zen Mod]

up to 100mV is considered as acceptable

however - try to decrease it , finding what's causing it

edit ........ typed around 06.00 , clicked send right now ...... and Pa is faster , again

 

[ArneRo]

Thank you for an extremely fast answer (both of you).

Then I am as cool as the amp... ;-)

 

[ArneRo]

Today my Stasis 3 amp started with letting med down.
The right channel now just deliver distorted sound and is useless.

Does anyone have any recomendation to what I can to to get it back in business? And is there a recomended set of components that should be upgraded replaced so it can continue to serve me in years to come?

Or is it ready for the trashcan? I really would like to get it fixed.

 

[Zen Mod]

no trashcan
also - no advice without any measurements made by you , according to posted schematic

 

[ArneRo]

This is rather embarrasing, but it was actually the speaker that had partly died... so the amp is still going. But do you have any suggestions about sensible upgrades that will keep it going for the years to come?

 

[Zen Mod]

not much except re-cap and checking condition of thermal grease under output biggies;

I'm always checking are biggies still tightly screwed to htsnks ...... well , when they aren't totally screwed

not that's probably issue in Treshold amp ....... and not that's easy to check in one


hm... maybe best solution for that sissy amp is - just ship it to OPLDF

 

[ArneRo]

Thank you for answer

Shipping it from Norway through half of Europe would cost a fortune I assume... ;-)

One last question. I have the amp on service now. What is the recomended BIAS values? My repair man said that the BIAS on the left channel was about zero, and he thought it also was low on the right channel.

 

[Zen Mod]

plenty of info in related threads (including http://www.diyaudio.com/forums/pass-labs/198589-papas-pubs.html?highlight=papa's )

from memory - setting it iteratively - up to 45-50C at inner upper corner of heatsink is sorta general rule