Threshold/ What is the Stasis topolgy?

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

Ferrari thankyou for your recent post on this slightly older thread. The info you provided will no doubt help other interested parties as well. Also Benie thanks for your reference to the above mentioned thread, very helpful.

Marketing? This has been asked before and some how we can't seem to get a consistant answer. I think I remember some one suggesting that "statis" topology allowed class A/AB amps to stay in class A longer. While we're at it perhaps some one can explain "optical bias" too. I'm also curious as to why these big amplifiers seem to have some what limited current output. Do these amps "double down"? What ever technical merits these amps have or have not they sure seem to have earned legendary "status". People whom I respect sure seem to respect these amps. I sure would like the opportunity to hear "statis/optical bias" for myself.