Review: Threshold FET Two sII Preamplifier


Category: Preamps

Threshold released the FET II Series II in 1985 as a upgraded replacement for the original FET II. And was in production until 1989 when the FET 9 was released.

All aspects were totally upgraded to a higher performance level than the original FET II. Torodial power transformer used,the phono section had additonal cartridge loading capabilities and the special attention was paid to the CD line stage input over the FET II. Pictures show the Fet II Series II as well as the original FET II.

The Threshold FET II Series II is a Class A operating preamp. Build quality is typical Threshold, that has become a bench mark. Circuit board is glass epoxy, mil-spec, with gold traces and through the hole hand soldered connections. No plug in modules or opamps in the circuit anywhere. Tiffany plated RCA jacks on the back of the unit, are custom made to Threshold specifications, as are all the interior parts,no off the shelf parts are used. All made to Nelson Pass specifications and all parts tested to 150% of operating capability, before being deemed worthy of the build in the Threshold FET II Series II.

This is typical of the empirical committment of Threshold under the guidance of co-founder Nelson Pass. And part of the reason that Threshold products have the longevity that they have. Truly built to last a lifetime and are easily handed down to future audiophiles with virtually no loss in sonics. Few other high end products can come even close to the overall presentation that Nelson Pass puts into each and every design.

As the nomenclature suggests this is a pure FET preamp operating in Class A. And has a wonderful liquid sonic signature as only Nelson Pass can design. The FET II Series II is a wide band preamp with a frequency response well beyond human hearing at 1.5Hz and 125,000kHz,distortion is 0.02 percent from 20Hz to 20,000kHz.noise is a vanisingly low -105dBA referenced to a 1 volt input,overall gain is +20dB.

In my opinion Nelson Pass once again raised the bar of pre amplifier performance to another level with the introduction of the Threshold FET II Series II. In fact I dare say this was by far more than just a revison to the original FET II.

Listed below is some of the playback material used in the evaluation of the FET II Series II.

Reference LPs.

Bob James - Hands Down (Columbia FC 38067)
Hiroshima - Self Titled - (Arista MFSL1-525)
John Coltrane - Blue Train - (Blue Note BST 81577)
Wes Montgomery - Bumpin' - (Verve V6-8625)
Rickie Lee Jones - Self Titled - (Warner BSK 3296)
Wynton Marsalis - Live Blues Alley - (Columbia PC2-40675)
Eric Gale - Forecast - (KUDU Records KU 11)(CTI Records)
Kenny Burrell & Grover Washington Jr - (Blue Note BT 85106)
Earl Klugh - Finger Painting - (Blue Note MFSL 1-025)
Larry Carlton - Friends - (Warner 23834-1)
Sadao Watanabe - Autumn Blow - (Inner City IC 6064)
Doobie Brothers - Minute by Minute - (Warner BSK 3193)
Santana - Zebop - (Columbia FC37158)
Pat Metheny Group - American Garage - (ECM 1-1155)
Frederick Fennel - Cleveland Symphonic Winds - (Telarc 5038)
Paul Desmond/Jim Hall - Complete Recordings - Mosaic(MR6-120)

Reference CDs.

Ben Webster At The Renaissance (Contemporary Records OJCCD-390-2)
The Royal Ballet Gala Performances (Classic Compact Discs CDSCD 6065)
Peter And The Wolf - Boston Symphony Orchestra (Sony SK 64079)
Jurassic Park Motion Picture Soundtrack (MCAD 10859)
We Get Requests - The Oscar Peterson Trio (Verve 810047-2)
You Won't Forget Me - Shirley Horn (Verve 847482-2)
Sneakers Motion Picture Soundtrack (Columbia DIDP 078100)
On Every Street - Dire Straits (Warner Brothers 26680-2)
Trio Jeepy - Branford Marsalis (Columbia CK44199)
Paris Jazz Concert - Louis Armstrong (RTE 1001-2)
Braveheart Motion Picture Soundtrack - London Symphony Orchestra (London LC0171)
Patriot Games Motion Picture Soundtrack (RCA 07863 66051-2)
Hook Motion Picture Soundtrack (Epic EK 4888)
Highlights From The Plugged Nickel - Miles Davis (Columbia CK 67377)

The FET II Series II played each format with convincing authority that only a handful of competing preamps could come close to. Compared to the original FET II it was a quantum leap forward. Particular the phono section. For once the CD section finally got this spot on and my CDs truly had a definite analog signature that the FET II fell somewhat short of. Getting back to the phono section, it is graveyard quiet at any volume level. And the addional loading capability lets one hear what a phono cartridge signature really produces,without the preamp influencing its signature in the phono section signal path. If your really into analog, this is one of the finest phono sections I have heard in 48 years in this hobby.

Whatever was done to the CD section, I am not sure of. But suffice to say the interaction between CD input and CD player is spot on. I am not a big fan of the digital format,but the FET II Series II certainly has made that transition far easier to listen to. In fact now I find myself listening to far more CDs than before.

What is really important is the music we enjoy as audiophiles. Without question the Threshold FET II Series II is a solid musical performer,whose only limitations is the source material itself and associated components in the system. You will find with the FET II Series II the possible missing link in your system.

When released in 1985 the Threshold FET II Series II carried a price of $1,290.00. Which in my opinion was one of high ends all time bargains based upon the total performance of the FET II Series II. At it's now pre owned price level, it is a gift - period.

Make no mistake the Threshold FET II Series II is not a panacea, it needs to be associated with like components of its caliber. It is not tolerant of other components, if those components are not up to the task. But with the given of having first rate components,the Threshold FET II Series II is a stellar perfomer that is seldom out classed by competing preamps. And at its now price level, I know of no other preamp that can come close to this performance. Although some 20 years since new, the FET II Series II remains one of Nelson Pass finest achievements in preamplifier design. A timeless classic.

Once again and as usual Nelson Pass took the design of the FET II to loftier levels indeed with the Series II.

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Thank you for the review. Your review helped me in my decision to buy one of these two months ago.

It is a very warm and detailed sounding preamp. Until yesterday, my system was a pair of 14 watt tube monos into LaScalas. I just purchased a Threshold SA/3.9 and the layers of detail and depth are now omnipresent. I really like how the phono stage sounds, but it is a bit quiet and dark sounding with my AT 150MLX. Maybe a resistor has drifted out of spec. The linestage sounds delicious with my CJ DA2B. Solid state + horns is very much out of fashion it seems, but it they are mating very well in my system. Does anyone have a schematic for this preamp?
A 3.9 that is Sweeeeeeeeet. Nelson always favored the SA3 and the SA3.9 regarding them as his favorite designs and rightly so, they are spectacular.

Before delving into possible resistor problems in phono stage I would try some other phono interconnects. With Threshold I have found Discovery Cables and Musical Design have worked the best for me.

Joe DePhillips is a friend of mine and if you need more info e mail me privately and will get you hooked up.

WoW very nice a SA3.9 - enjoy.
Just had Jon Soderberg recap it with Black Gates and a couple of Solens (where they could fit.) I have only listened for about 6 hours; so far so good! Zero fatigue.

I have to agree with MFSLgoldCD. After having had the opportunity to listen to the SP-11 from Audio Research, dozen of Sonic Frontiers preamps, CODA, and PS Audios current model CJ and BHK preamps I came to the following conclusion.

The reason that some people have experienced a flat-sounding Fet 10/E is more likely that the capacitors which are WonderCaps are still ok, but have dried to a point where it gets more audible than they are losing transparency. That being said the sound usually read in Fet 10e reviews that stands out against anything, was no longer there and I experienced this myself. I did email Nelson Pass a few days ago and he suggested replacing them with Wimas or Clarity Caps. Just a good industry standard is well enough to get it singing again.

You folks guess what. I did choose Roederstein Capacitors Arnie Nudell, Paul Mcgowan did use back in the ’90s. I switched a small capacitor before the main caps on each four of this per channel. I also added bypassing caps and installed a filter against dirty power in the HF region. Furthermore, I added ELNA passive attenuators at the volume and balance level.

Now I am just saying one thing. I put an Audio Research SP-15 from Life Like in Germany to test and my Fet 10/E blew it away in any way because it simply is soo much better than the SP-15 and all the edges and flat or collapsing soundstage has been gone.

It is unbelievable how it sounds as it has more air than any tube amp I have heard including the CAT SL1, Audible Illusions Modulus 3, and Counterpoint SA-5000. Just to name a view. The instruments are far separated, airy and not bubbled edges, almost voices female voice are close to touch and have an easy sense of air. I always have goosebumps on my skin -never changed it.

In comparison with the other preamps, none of them, not even a Counterpoint SA-5 or Motif MC-7 did come close. This is simply amazing.

I was using Infinity Kappa 9’s and IRS Deltas as my main speakers driven with Threshold power amps.

I will do further comparisons but I assume since the current bad Covid situation got me off tube replacements and I found a better way of keeping the sound I like.

So, far no preamp I used beat the Fet10E. Recently, a First Sounds Presence was close, but not really better.

And... the cliche it's more forgiving in the bass is not true once you rebuilt it has a bloom base you hear on live concerts.

Gosh, I am sitting in my chair in absolute bliss :-)