Threshold STASIS 2 Totally Rebuilt and Upgraded Pass Amp

Threshold STASIS 2 total rebuild/upgrade with modern high-performance components. General Specs: * 200 Watt/Channel in to 8-ohms STASIS Stereo Power Amplifier. * Constant voltage/constant current linear state design. * 24 - 16a 250v output devices per channel. * 120v 50/60Hz mains supply. This Threshold Stasis 2 is from what's left of my Threshold collection and has well less than 500 hours of on-time since rebuilding. I used it to power the LF section of my bi-amped Apogee Duetta Signatures and normally the amps are not left on when not in use. Cosmetics are near perfect on the front panel - Never rack mounted - only occasional small fine scratches or maybe a micro-nick here and there when looking over the entire unit - always well cared for. Totally rebuilt in November 2010. No circuit modifications were made - circuitry is exactly as Nelson Pass design it - only upgraded modern components were installed which improve sound quality, reliability, and stability. The sound quality of this rebuilt STASIS amp easily holds it own against most any currently produced high-end solid-state amp. The reason is attributed not only to the upgraded parts, but moreover, to Nelson Pass's straight-forward STASIS design that has stood the test of time. Rebuilding of this Stasis 2 includes, but not is limited to, the following: * Upgraded the aluminum can power supply filter caps: 22000uf United Chemicon 100v bypassed with WIMA polyester film caps replace original 15000uf 75v units. * New Blackgate Standard electrolytic caps replace the old and dried-out original Instrument Devices small electrolytics. * All new Emitter Resistors: Dale 3W Metal Film resistors replace old carbon 2W resistors which are notorious for changing value with temperature and age. *Sonicap Gen II film caps replace original small-value film caps. * Upgraded from single-turn bias-adjustment trim-pots to ultra-precision 25-turn Borns trim-pots. * WIMA Polypropylene film caps replace same value tantalum caps. * Vampire high silver-content solder. * Power switch (actually a 20A breaker) replaced with an original appearance Carling high-reliability circuit breaker. * Cardas CCBP solid-copper five-way speaker binding-posts sets replace cheap-plastic originals binding posts * Upgraded RCA jacks. * All parts were sourced from DigiKey, Mouser, Newark, and Sonic Craft. * Bias set to factory specs. * Power output verified linear and matched between channels at 20Hz, 1000hz, and 20kHz. * Verified for zero oscillation with calibrated Tektronix 465B oscilloscope. * Adjustable DC offset implemented via 25-turn Borns precision trim pots. * All original factory-matched output devices - no mismatched output devices from past repair job. * Offset and bias and will be re-checked prior to shipping. * Technician-level instructions with photos will be provided via email for bias and dc offset adjustment procedure. Please note: A few people have asked me why I performed these "mods" and how does it sound now? First off, the "upgrades" or "updates" performed on this STASIS 2 power amp were not at all mods. Mods imply the circuitry design was changed in some form or another from the original. No changes were made to Nelson Pass's original STASIS design. Just better, modern-design components that were simply not available when the STASIS 2 was built replaced the originals of the same values. The only place that may be considered a mod is in the power supply where larger than original main capacitors with bypass caps were used, but still there were no circuitry change made. You have to remember that STASIS 2 power amps were all built between 1979 and 1981 and they contain a number of electrolytic and tantalum capacitors. These types of capacitors all deteriorate with age and all have a factory rated finite life-expectancy. Combine that with the fact that many people leave their power amp powered-on for years at a time, these electrolytic capacitors were past their end-of-life over fifteen years ago! Long before worn-out electrolytic and tantalum capacitors lead to reliability issues, they cause the sound of the device to slowly deteriorate as the capacitors' internal leakage increases and their original values change. For this reason, there is a huge difference in the sound between a Threshold STASIS 2 power amp containing new and modern capacitors as opposed to one that has never be updated. At this point, every piece of audio equipment over 20 years-old that contains electrolytic capacitors - including every classic Threshold piece like the STASIS 2 - is past due to have every one of its electrolytic capacitors replaced and really should have all of its tantalum capacitors replace with something better. Solid-state devices, like diodes, transistors, and FETs, film capacitors, transformers, and the like, for all practical purposes will last forever under normal use. Just remember, if you find that 20+year old classic piece of equipment that you've always loved, and it's never been at a minimum, "re-capped", be sure to factor that service in on the price since it's going to have be done as soon as shows up on your door step. As for how does this Threshold STASIS 2 power amp sound now after the upgrades? Well, it sounds like a brand new STASIS 2, with all of the qualities of the original STASIS 2 but because the of better quality capacitors, emitter resistors and other upgraded parts, it now has even greater dynamics, imaging, and extension, as well as it being more transparent with a quieter background than when it was brand new. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Please allow a couple of days for packing since it will be massively over packaged with thick foam padding for safe shipping. No fee for PayPal. Contact me for more pictures with greater detail or questions.