Write to Nelson Pass at Pass Labs.
He designed it.
He designed it.
Threshold/ What is the Stasis topolgy?
I own a Threshold S150 series ll amp and even with a 4 ohm load you can hardly tell the amp is powered on. It runs extremely cool yet sounds hot especially in the critical midrange. Is this the Stasis topolgy? Or does anyone know? Any info would be appreciated. Thanks.
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Ph.D, Couldn't find too much on this. However here are 2 links that *might* be of help:- http://www.threshold-audio.com/discontinued.html & this one is courtesy member "Mitja" from another thread: http://www.rsvlonline.net/vintageamp/archiveamps.htm The 2nd one is hosted by Jon Soderberg (formerly of Threshold) who now specializes in Threshold/Forte repair. He might be another good person to contact, if you haven't already. His home page appears to be: http://www.rsvlonline.net/vintageamp FWIW. |
Thankyou very much for your input. Bombaywalla, you have especially provided some excellent information. I will call Jon Soderberg to find out more information and to see if this amp can be upgraded however I am reluctant since it may change what is already a very excellent sound. Maybe he can convince me otherwise. PHD |
While delving through some of my Threshold archive papers the following was found on the Stasis topolgy. Single or dual channel, non-phase inverting audio power amplifier employing circuitry to suppress voltage and current variation and enable performance to be dominated by a system maintained in a stasis condition of constant voltage/constant current, linear state operation. No overall negative feedback is employed around the amplifier system. No output protection circuits are utilized. Active constant current sourcing is employed at every gain stage.Power is sourced through a one kilowatt transformer and greater than a 70k microfarads capicitance. Thats the basics of the Stasis topolgy. Your Threshold S 150 Series II is a further refinement of this technology. I have an original factory brochure on this power amp I can copy and send you if needed. |
Phd check out the amp form Thread ( Threshold S150 or Forte 4A) There is a mod that you can do which involes moving the transformer forward 3 or 4 inches. I've done it with my S150 and the differance was huge. Your S150 is very good but it can be much better with this Mod. Ferrari I have read some of your great reviews on the Forte Amps. Came across them when I was buying a Forte Model 6. But I have been looking everywhere for info on the S150 if I could get a copy of the manual I would really appreciate it. I would even come over and wash your Ferrari for you if you give me the keys!!! Thanks |
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