Keep Vintage or sell for new

Omg yes. I bought a brand new Threshold s500 when released in ~80. Then a T2 preamp … then a Pass x350 ten or twenty years later. I can’t begin to tell you how much better contemporary stuff sounds! 

Every ten years the sound was significantly improved. My old Threshold stuff sounded thin and transistor like. Each generation has been warmer, more realistic, greater current.

Pass labs (Pass being designer of Threshold) is a really good choice. But honestly I have to recommend considering  a tubed preamp. the preamp really is the soul of your system, and a tube preamp can add real magic to your system.
 

Audio Research, VAC, and Conrad Johnson make amazing preamps with great midrange bloom and rhythm and pace… very musical and you get the detail. But it is a mater of taste… but for me, once I put a pice of tube gear in my system… it would never be traded back to solid state. All my stuff is now tubed: Audio Research.

Hey Mission

Care to qualify your answer?

Keep the FET 10! Why spend thousands for a new preamp? Sonic differences between the FET 10 and today's gear are not enough to justice the cost! It was an excellent preamp when new and remains so today.

If the job of a line stage is just to transfer signal and offer control, I don't think you'll find much improvement over the Threshold fet 10 HL. In that role, it is one of the all-time classic neutral devices. And the basic high build quality with its corrosive resistant gold-plated circuit boards suggests that it could be an heirloom product. Which is not to suggest that a refresh wouldn't be a good idea. 

The Pass and BHK could offer convenience features such as remote control, and perhaps offer benefits via balanced connections. 

I doubt you'll hear an improvement that will warrant the extra expense.

Your Threshold remains a great preamp with qualities that some new designs cannot dream of.  I remember the rave review at Stereophile by GH.

But reality tells that this is a 30 year old design, a long time for a preamp no matter how state of the art in its days.

Best is to compare it with your mentioned options side by side or take the leap of faith. Most likely it would prove a wise choice. 

Thanks unsound and Bourne

Appreciate you taking the time

I think it's a great preamp...my mind wanders to what else might be out there...the Pass Labs and PSAUDIO are a chunk of change for me so your responses are quite helpful.

Stick with the FET 10. Just because something is new doesn't guarantee that you will like it better. A good case in point is the 65 year old Quad 57. Many Audiophiles and speaker manufactures still consider it the Holy Grail in speakers!

Yogi>

Wow!

"revered by critics the world over as one of the most natural sounding speakers ever built, may well be the most beloved speaker of all time."

Wow once more

I was pondering this same sort of situation. (Read the thread on timeless amp question in this forum) My Amp and preamp 20 years ago were around $25K MSRP. So as you, I wondered if there had been advancements to encourage me to replace them or bring them up to the most recent version from the factory. After reading the overwhelming comments on the topic I will remain on course and be sending them in to VAC for the Mk III upgrade. They just still sound wonderful to me and i know they are well built because they still work perfectly after 20 years! VAC is a small operation and known for quality components, I also like the fact the Kevin Hayes listens to everything before it leaves their doors to ensure it is voiced as intended, this includes any upgraded components as well. You may as well consider sending your pre amp out to Threshold and see if they can go over it and bring it back to new? They have an update/upgrade program on their website. This audiophile nirvana can get the best of us sometimes and cloud our better judgement. Good luck!

I've decided to try the PS Audio BHK pre for 30 days.

They make it easy enough...if I don't like they will take it back.

Thanks to all who responded 

To expand on @fthompson251 's recommendation you might want to also consider:

About | vintageamprepair (wordpress.com)

A Threshold tech around when these units were made and endorsed by Nelson Pass.

Thx

Sent an.email to Threshold as I believe they offer the same...never heard anything back

I have heard both preamps and I came to the conclusion that a recapped FET 10 HL sounded nicer to my ears.

It had a bloom bottom end, rounder, better extended base I imagine to hear from live concerts. The midbass was clearer and more foward than with the BHK. Also, the top end seem to be rendered more softly with the BHK, however, to my point of view detail was missing and it was too soft and not present enough.

On the Threshold the top end is a little sharper and more intense than with the BHK, but after recapping it didn’t not bother me. I loved the detail and the seperation of the instruments that were better than with the BHK.

Well, now you can blame me for using a solid state device before a tube unit, but well, it sounded more real to me.