PASS Threshold Stasis Amps question

[bobdebouwer]

Hi,

Edit: it is the S/300 model, the big granddaddy 🙂

I heard the designer of this famous amp is on this forum,so wanted to ask some questions I could not find an answer on online.

How does the amp handle low impedancies <1 ohm, as happens with vintage infinity speakers?

Which kind of upgrades, revisions would you expect to be making on these as they are close to 40 yrs old? What would this cost?

They are getting old, but the design is timeless, what would they be worth, in full original state? I could buy 2 for 3000 euro which seems both tempting as it is expensive

Thanks!

 

[gary s]

Where is ZM when you need him?

 

[Zen Mod]

ZM is furniture

Though, these are questions for Architect

except that one - yes, go buy a pair for 3K, bargain

considering what else drek is paid nowadays same greenies

 

[gary s]

I agree with ZM, 3000 Euro for 2 of these classic amps is a steal. Then you can research here on the forum for many posts on these amps and what can be done to upgrade them at your leisure. If they are both in working order - then you are on a winner.

You only need one for a stereo amp.

 

[bobdebouwer]

Ok thanks! Will need to convince the wife and see if I can get a deal as he is also selling his infinity rs 4.5 speakers. Was thinking of bi amping them hence buying 2 of them. Might be a slight overkill.

Looking forward to the technical answer. I hope they will be able to cope with low impedancies, as they were very high regarded at the time.

 

[Zen Mod]

there is no overkill, when A Class heat is in question

 

[bobdebouwer]

If I'm not mistaken "only" the first 10watts are A class, then it goes to AB. Runs cooler off course, for sure withlow impedance loads.

 

[gary s]

First update, would be to upgrade all the electro caps, then check bias and readjust. ZM has posted many hints on this amp with bias requirements and schematics I believe.