Threshold Power Amp

[triceratops]

I have an opportunity to purchase a used Threshold power amp, model S/300 from the mid 1980's. These are A/A-B solid state amps (150 watts/channel) designed by Nelson Pass and are highly regarded in some circles (I don't think there is any huge following among horn speaker fans though). It is a pristine one-owner piece but the asking price is a lofty $1100. Does anyone have any thoughts about driving my 1975 Belle Klipsch with these?

Thanks for any input!

Best in horns,

triceratops

[khorn58]

Im using a Threshold s/150 and fet 2 preamp from the same years with some vintage khorns.

This is a real warm detailed smooth amp you should like it .

1100 is not a bad price but I have seen them on ebay for less.

I like thershold with horns as did the Music box (Hign end hi fi store orig 50,s klipsch deler) back in the day.

Mr bell like them better than the macintosh tube and soikld state amps he sold.

[sheltie dave]

Tri, I would say you can do a lot better for $1100. Heck, I'd buy one of the decent Nakamichi TA series threshold receivers for $1-200, and buy a dozen roses for the wife, and bank the margin for a future item. I'm assuming you have your Khorns on your primary system, so hit me with the dumb hammer if it's otherwise...

[jt1stcav]

Hey, you could do a whole lot worse! Threshold have always been highly regarded in their overall design, and their sound quality has always been first rate. If you have the opportunity, then go ahead and try it with your Klipschorns. Personally, I'd rather use tube amplification for the big horns, but that's only me...there's absolutely nothing wrong with state-of-the-art SS amplification (as I can attest with my McIntosh amps). If on the other hand its sonic characteristics don't appeal to you, then you can always sell it for the price you paid for it, maybe even more!

Good luck in your decision.

[triceratops]

Thanks for the feedback, everyone. Dave, the 1960 Khorns are going to be driven by the 300B Welborne DRDs that a friend of mine is finishing up. Those are going to go in a not-yet-built garage bedroom that will hopefully be my primary listening room.

I have a Threshold FET 1 Series 2 Preamp and I was thinking it would be an interesting contrast to run this preamp with a solid-state power amp into the 1975 pair of Belle Klipsch in the living room. I figured that way I could have decent representation of both high-wattage solid state and low-power SET gear in the house.

The condition of the Threshold S/300 amp is super clean cosmetically--if it had the box I would call it mint. I was hoping I could resell it if it didn't sound great to me.

Best in horns,

triceratops

[triceratops]

khorn58,

The S/150 that you have is very similar to the S/300 in design and vintage, and as you know my 1960 Khorns are a lot like yours, too. Have you heard any other Threshold models, and how do you think they compare to these "S-Series"

Thanks!

triceratops

[Colin]

I havent heard the Threshold amplifier, but I did hear the superlative Pass X250 concrete monster amplifier, which was also designed by the god of monster amplifiers, Nelson Pass. Does that count?

The massive X250 puts out 75-watts of Class A power before switching into A/B mode. It is capable of not only 500 watts into a 4-ohm load, but also 1000 watts into a 2-ohm load! This mammoth amplifier did sound great on my big ole horns of course, but then it should. It cost $4K used.

The price of high quality amplifiers has skyrocketed in the last decade. It is as if the Internet boom never crashed: audio prices are still way too high (at a time when the market is shrinking by 30%!). My 48-pound, 70s, solid-state, Class A, 22-watt (60-watt max.), Pioneer M-22 dual-monoblock amplifier cost $750 in the seventies. It should cost about $2K today. Yet Threshold amplifiers (with the same THD and lots more power) are nine times the price.

The Pass amplifier rarely used any of its power on my big ole horns. When it did of course, it sounded wonderful. Slightly more control and authority to the bass. Lightning crackling in the Xmen movie sounded better than any amplifier I have ever heard. Though lightning crackling is a rare musical event, it certainly showed that the power was there when called for.

When it was NOT clipping however, it sounded just as good as any refurbished tube amplifier or very good vintage solid-state amplifier: it sounded the same as my $5 vintage solid-state harmon/kardon 330B receiver. I recently heard a Macintosh solid-state amplifier on classic Klipsch corner Khorns. It too seemed to be a very quiet and clean performer with out any apparent weaknesses. My Bottlehead 2A3 Paramour monoblocks almost had a slight advantage over the Pass amplifier in 3D illusion (imaging) and mid-range sweetness.

I did NOT listen to the Pass amplifier in long extended sessions, but I have had it at my house with several different loudspeakers on different occasions. Though double blind studies on cone loudspeakers indicate that moderate price solid-state amplifiers can wear out listeners ears over time, I heard no such affect in long evenings with the Pass amplifier. I did experience this affect with my Pioneer M-22 (but that has plentiful feedback).

Your system profile doesnt list your front-end equipment, so we cant tell if you have a powerful sub to support your big ole horns. But if you do, that frees up your amplifier choices. The sub can give you a solid feeling to the low and mid-bass, allowing you to use a low-cost, sweet and delicate sounding tube amplifier for the mid and highs. In my own humble opinion, this is the best of both worlds.

Your system profile doesnt list your loudspeakers either, so we cant tell what your power requirements really are. IF you have classic Klipsch corner Khorns, the amplifier needs to be extra clean and sweet, with almost no power. Your sub must be extra deep, powerful and high output to properly match the loudspeakers.

[Guy Landau]

The S300 is a very nice sounding amp, but $1100 asking price is on the high side. There's a very nice unit on Audiogon for $825 http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1088822181 .

[J M O N]

T-Tops:

I have owned a few Threshold amps in the past, including the S/300. At the time, I had it with Cornwalls. As mentioned, Threshold makes some very nice equipment. I paid about $900 for mine about 6 or 7 years ago, so I think the $1100 price is on the high side. I also owned the S/200 and CAS-1. All nice products.

Just thought I'd also throw in some of my experiences. While owning the S/300, I came across a good deal on a Classe Audio Model Seventy. It's a smaller amp and "only" put out 70 wpc. You can find it used for about $500. I think I actually preferred it slightly over the Threshold. I later bought a Jeff Rowland amp that just slightly bettered the Classe, but it was much, much more expensive. Have you considered going with tubes? I eventually bought a used ARC VT-50 tube amp that put out 45 wpc, and it was a big improvement over all of these. It was also less expensive than the Rowland, and only slightly more expensive than the Threshold.

[khorn58]

triceratops,

I am using my Thresholds with a pair of stock 58/59 khorns. You just can't go wroung with this vintage Threshold ,they should hold there value and mostlikly rise. I think Thresholds amp are some off the best amps ever made. I do rember that the Nakamichi made threshold amps hade a few chages (more speaker protection) that changed there sound and were not bult to as high a standard. but are were still ok amps.

I would buy anoner silver face threshold again.

Soon I will have some scott 220a mono blocks to comare them to.

[triceratops]

Colin-

Thanks for the detailed post. I don't have my gear listed on the profile, but the S/300 Threshold described above would be used for a second system. Upstream would be a Threshold FET 1 Series 2 Preamp, and a Pioneer PD-65 Elite CD player. The speakers would be 1975 Belle Klipsch. As mentioned earlier, my main system will be 1960 Khorns run with Welborne DRD 300B SET amps and an as yet to be determined CD player (any suggestions welcome!)

Guy-

Thanks for the tip. I realize the Threshold is on the high side price wise, but it is a super clean silver-face unit. It is local so no shipping cost and the seller would offer a 30-day warranty.

Jmon-

Thanks for the suggestion on the Classe amp. The Threshold S/300 is definitely overkill on the power output. For tube amps I currently have an Eico HF-81. As noted above, I will soon have some Welborne 300B DRD SET mono amps and the Threshold will be for a second second

Khorn58-

Yeah it would be fun to check out the Threshold with the 1960 Klipschorns in addition to the Belle Klipsch. I like the appearance of the Thresholds w/ the silver face and the build quality looks impressive.

Best in horns,

triceratops

[triceratops]

I meant to say:

Jmon-

Thanks for the suggestion on the Classe amp. The Threshold S/300 is definitely overkill on the power output. For tube amps I currently have an Eico HF-81. As noted above, I will soon have some Welborne 300B DRD SET mono amps for the '60 Khorns and the Threshold would be for a second system in the living room with the '75 Belle Klipsch.

Best in horns,

triceratops