Threshold FET-nn Pre-Amps - Anti-Static Concerns

[Geeqner]

Anybody with experience with these products -

On a scale of 1-10 (1=Nearly NO Concern / 10 = Very Delicate & Problematic)
How concerned to I need to be about anti-static measures when removing the boards from the chassis to replace a few caps?

I would assume that the Phono / Line Stage board is potentially of more concern than the Motherboard / Power Regulator board.

I USUALLY wear a static strap and work on a mat as a general precaution /
touch something grounded before touching any part of almost ANY semi-modern Circuit Board Assembly (I'm a big believer in "Better SAFE than SORRY", and we're in the cool and dry time of year in these parts.)

However, do I really need to exercise more serious measures for these units?

 

[coolnose]

If you apply the good practices you prone I think you should be fine, they weren't built by antistatic virgins from outer space anyway...

EDIT: When I am really concerned about that stuff I usually put a (conductive) clamp across the pins of each FET, not sure it's usefull though..

 

[Nelson Pass]

The one part I would have concerns about are the P channel Mosfets, if I recall
correctly 3N172's on the Vas section of the circuit. Their Gates are delicate.

Everything else, no big worries.

 

[Geeqner]

Thanks for the replies.
Good info that a rookie like me needs
(Particularly, since I do not officially "own" it yet, and I want to avoid boogering it up.)

And I see (4) of those little 3N172 4-legged tin-can bugs on the Line / Phono PCBA.

Fortunately, they do not appear to be directly coupled to anything that I'll be messing-with (but I WILL exercise a little caution nevertheless).

So, does "THE MAN" do this from memory, or does he consult his schematics or log-book?

 

[Zen Mod]

that preamp is hard to bugger up , if you follow sane logic - if needed replace old electrolytics , and that's it

 

[kstagger]

Back when I was a vacuum tube guy - Point-to-Point wiring, baby! - I replaced the caps on my then Threshold FET-10/HL and -10/PC without any damage.

Two pieces of gear that I wished I had kept instead of chasing other preamps; they looked quite beautiful stacked.

 

[Geeqner]

Yeah - I'm REALLY looking forward to firing this baby up and hearing the difference.
I'm presently using the Pre-Amp Section of a "classic" NAD 7020PE

The Threshold, being "REAL HiFi", even at its advanced age should still be SUBSTANTIALLY better (particularly, the phono section)