Help need speaker to match Threshold 4000 amp....

Hello, I have a newly acquired Threshold 4000 (200 wattts class A).Temporary using s/s Nikko Alpha pre-amp but thinking match this amp with Cary SLP-98L in a Month.

my own choice is a Proac Tablette 2000 or Proac Response 1sc or planar? under $1,200
Your recommendation please.Thanks a lot pescolar.
Just FWIW the Threshold 4000 is a fantasic amp,although a wee bit long in the tooth by now, unless it has been serviced. The 4000 was not designed with tube electronics in mind and over the many years dealing with Threshold products I have never heard a 4000 work well with a tube preamp. It was designed for the Threshold NS10 and SL 10 preamps. Although the Threshold Fet 1 and Fet 2 preamps will work quite nicely with the 4000. The Nikko pre you have is holding back the 4000, so a better preamp is indeed called for. My last 4000 was paired with a Klyne SK5A preamp and it was spectacular sonically. One of my worst decisions was to sell the 4000 and the Klyne. I now have Spectral gear and it is as good if not a tad better than the Threshold, but I gotta tell ya the 4000 and Klyne set up was very special indeed.

If you do want to use the Cary just make sure you can return it if it doesn't work out for you. I do have my doubts on that based upon folks having gone that route. But you just might luck out and find a match.

As far as speakers go I am not a fan of the Proac line, just my opinion, many folks love them. I use Alon speakers and have found them to my cup of tea and as always others will disagree. Speakers are a matter of personal taste. You do have to audition speakers to hear for yourself if that is the signature that pleases your ears and musical preference.
Why not buy the gear that the amp was designed on? That would be the Dayton Wright XG-8 and 10, and the Snell Type A?
How about Lector Zoe Italian Preamp...I heard this is a very musical pre.
I talked to Mr. Jon Sodenberg and told me older tube pre will work and any tube pre will work especially Audio research.
I am looking for a Lector Zoe Pre and do the speaker later.
Member please need more input for right speaker and preamp.

Wow! Snell Type A. haven't heard those for some time. They were absolutely wonderful speakers. anyway, just remembering good times.


Not much help on the Lector Zoe Preamp as I have never heard one. However the AR gear I am fairly up to speed one and if I was ever to return to tube gear I would look for the SP8 or if I had big bucks the SP10. Both would require service from AR at this stage of their life. I am just not a fan of tubes anymore. From 1957 to 1977 was knee deep in tube gear, just wore me out over those years as well as my wallet was getting thin in keeping a supply of back up tubes always on the ready. When Threshold and Levinson came along I was out of tube gear at damn near light speed. In fact more like warp factor nine and haven't looked back. I have no fond memories of any tube gear. Others on this post will dissagree, but for me tubes are not a memory I wish to revisit. But good luck in your search, I wish you the best.
Yesterday I got few minutes late.There was a Lector Zoe came out for sale at Audiogon for $800 ...Ht by pass not working...anyway I think I am going to ARC pre.
Ferrari, i will check n read regarding ARC SP8 & SP10 and read more.I have to be carefull on choosing what I want.So I won't look back any more and then find the speaker for my future system.Any feed back on Dynaudio Contour SE..never heard of it.

Ferrari are you close to Brentwood right?

watch out for the really high output impedance of the ARC preamps that might make it very diff to mate to the very low inp impedance of the Threshold 4000. The result will be very lack-lustre sonics.

Any tube pre-amp recommendation mating my Threshold 4000.

How about Cary Slp-98 (output impedance 400 ohms)

Can anyone have any information about the input impedance of Threshold 4000..I am trying to google it and no luck yet.

Mr. Jon Soderberg ( nice guy) e-mailed me almost a week now and told me Threshold 4000 amp input Z is 15k.

Is there anyone out there can explain or how to match the right number for the pre-amp out put?

I use the ARC SP17L with my Threshold Stasis 2 and like what I hear.
But the SP-17's impedance is 60k... I think my Stasis 2 is 15k just like the 4000a
I am confused about this 4000 amp input impedance.

1.My e-mailed responsed fr Jon Soderberg regarding about 4000 ,input impedance is 15k.

2.e-mailed responsed yesterday fr.Nelson Pass,input impedance is 75,000 kohms.

3.One member from this trade :
Input impedance is 75k ohms according to 4000 manuals.

With all my respect mentioned name above I do believed to Jon Soderberg for his top notch P/M & upgrade & advise
Same thing from Nelson Pass information.
Which is which now 15k or 75k ? HELP!pescolar
I apologized for last #
It should be.
Nelson Pass designed the thing. I would listen to him.
I'd say you're between a rock (Soderberg) and a mountain (Pass), both extremely knowledgeable about Threshold (understatement), but like Taam I'd have to give Nelson the nod. I was the one who sold the 4000 and posted the specs you linked, Nelson's answer matches the 75k in the manual (I have another 4000 for sale - rebuilt by Jon). 

During the almost 30 years I used the 4000 I paired it with an NS-10, an Amber Model 17, an ARC LS-1, and an ARC SP-16 (even a Dyna PAS3x for a little while ... Ha! PAS on Pass). I have fond memories of the NS-10, though I liked the SP16 best, that said there are a lot of good preamps out there, you'll get good advice here. 

As for speakers I had Tympani IIID's at first but Beveridge Model 3's most of the time - vertically bi-amped with 2 4000's for the last few years. In the end they were mated with Maggie 20.1R's. As noted they can drive about anything (the Bevs reportedly dropped below an ohm at the high end). 

So one mans pairings with a great amp, sorry to go a bit long winded, been a while since I've posted on the 'gone. 
05-19-11: Pescolar

Any tube pre-amp recommendation mating my Threshold 4000.

How about Cary Slp-98 (output impedance 400 ohms)

looking at the specs only, the Cary SLP-98 looks like a good match. Anyway you can audition it/try it before buying?
Another person I know (who has a Threshold T series amp) uses a Music First Audio (MFA) passive TVC preamp & really likes what he hears.
An obvious match is what some others have already recommended - the Forte (down-market Threshold brand) & Threshold s.s. preamps such as Forte F-44, Model 2 OR Threshold FET-9, FET-10HL, T-2, T-3.
I wanted to clarify my post above. I contacted Nelson about my Stasis 2 and he informed me the following.

The input impedance is 75K. There is a 4.75K resistor and then a 10K resistor, the 10K has been bootstrapped to
a 70K value.

So the 75k reported looks to be the correct answer for both the 4000 and Stasis 2.
I have to agree that 75k input impedance is the right one.

-----Original Message-----
From: Nelson Pass
To: junpablo
Sent: Wed, May 25, 2011 5:32 pm
Subject: Re: Vintage Threshold 4000 Class A amp:/ Need specifications/ Input Impedance:

I looked at the schematic, and a quick calculation shows 75K. The 15K value is
in error - the 10K value he is looking at has been bootstrapped to a 70K value. and
is added to the 4.75K input resistor before it.

Bombaywalla, recently sold all my tube gears including Cary SLP-98 for financial reasons and now I am starting to build a budgeted system.I am familiar with SLP-98 and actually I kept enough 6sn7 and extras...will be a little cheaper if i decide to slp-98...but dreaming to have ARC too.if i have extra dough then ill go to all Pass Labs gears.
Last Memorial weekend just happened in one of my friends party to auditioned a "DYNAUDIO AUDIENCE 82".

First time I heard this speaker and make me decide to go for Dynaudio Speaker ,now first choice.


Any idea on the used priced market?Thanks.pescolar