Tube amps for khorns

[Khornfan]

I've had my khorns for about a year and recently took the plunge and bought a tube amp, a receiver actually. The Harman Kardon TA5000X is essentially a A500 amp with an am/fm tuner. It has been recapped and has a new complement of preamp tubes as suggested and supplied by Jim McShane. The difference in the tubes is noticeable! In my 40+ years of hifi ownership this is by far the best I have ever had. The music sounds REAL! I can also listen longer and louder without ear fatigue. But now my curiosity is on a new level. My question to the forum is this: How much difference would I hear if I were to change to a VTA ST-70, VTA ST-120, Citation II with upgrades, or any other suggestions? Of course this would also mean a good tuibe preamp to go with a new amp.

[pauln]

Well, just let me say this about that...

I also have been a HiFi enthusiast for about 40 years. I had Heresys for about 30 of those years, then got La Scalas. I wish I had done that many years earlier. I also tried a couple of amplifiers, including a 250W/ch Carver, but about ten years ago I got some single ended triode mono blocks and tube preamp. I wish I had done that many years earlier.

To answer your question, it is impossible to say for a specific situation. But generally, my advice would be to not wait to find out.

[Bob Latino]

Disclaimer > I sell the VTA ST-70, VTA ST-120 and VTA M-125 amp kits.

KHornfan,

With KHorn's which are about 105 dB efficient the VTA ST-70 would have more than enough power. The VTA ST-70, although rated at 35 WPC, will actually do 45 watts over most of the audio band without clipping. See test link below.

http://www.knizefamily.net/russ/electronics/electron-tube-audio/dynakit-st70/performance/

Another thing would be to specify the lower gain version of the VTA ST-70 amp. The lower gain version of the VTA driver board works better with higher efficiency speakers like Klipschorns.

There is also a link below on this forum about Klipsch Grand Cinema speakers being used with a VTA ST-120.

http://forums.klipsch.com/forums/t/107114.aspx

Bob Latino

[Cut-Throat]

or any other suggestions? Of course this would also mean a good tuibe preamp to go with a new amp.

I will second the recommendation from pauln about SET amps. I use 45 SET amps with my Altec/Khorn Combination. They are driven by a 6SN7 tueb pre-amp.

[Erik Mandaville]

I also agree with Paul and CT, but I also have heard more powerful amplifiers sound spectacular on both our Klipschorns, as well as a recently acquired pair of La Scala LSI (tapered top, split sections, fiberglass, aluminum trim) in really good condition. I've really liked the way the La Scalas sound, but this model is sculptural and sort of industrial-tech looking at the same time. I Got them from a very nice family nearby. I'm using the La Scalas with a Transcendent Sound SEOTL, which I have to say is really among the very best amplifiers I've had. I've looked at Bob's kits many, many times, and they seem to be extremely well thought-out, with very good parts, bullet proof chassis, and also heavy power if needed. As much as I like the lower power single ended amps, they have not been able to quite compete, in my experience, with a bit more muscle in the low end. That's just been my perception and is therefore nothing but an opinion. The SEOTL (OTL = output transformerless) is an exception, however. The control this amplifier has (with about the output power of a 45 triode) in terms of bass response is really iron-fisted, despite it's low power.

I have to mention a second system:

We recently received a custom-built pair of absolutely stunning new horns from The Horn Shoppe! these little things with a 4" Fostex driver hit so far out of their league it's unreal. And they are so small! Like our big Lowther horns, they need break in time -- the single, full-range (well, maybe not literally -- at least yet) drivers really need time to loosen up and relax. Out of the box they are a little bright for the first few hundred hours.

If you can try some different amps, that would be good. That way you can form your own opinion.

Have fun!

Erik

[captmobley]

Where are you located? Someone near you probably can give you audition with some different gear to give you a choice of amps. i run Khorns with Welborne laurels 300b SET (9 watts) and recently recieved a pair of Welborne Moondogs 2A3 SET(3.5) watts and feel that I am probably happy for quite a while(until the upgrade bug bites again)

The SET sound is truly addictive and Khorns utilize every watt to it's fullest. If you are in West Florida, feel free to come for a listen!

[Audible Nectar]

SET can be very alluring, however it can also be very restrictive depending on what you listen to (and what dynamics are required). For me, the "be all end all without going broke" 2 channel Heritage amplification solution is the custom built NOSValves VRD monoblocks, 60 watts per block of custom-built-for-Heritage, tube rectified KT88 goodness. With the quality preamp of your choice, it's a setup that could well be a "lifer". I had mine stuffed with top flight caps and vintage tubes for even better performance.

I am also a big fan of McIntosh MC30s but for specific reasons....the VRDs are so audiophile right that I can recommend them for KHorns without reservation. A vintage Mac tube system can be as good as anything out there - for certain tastes. Midrange is sublime.

I do agree that listening to these recommended amplifiers is the way to find your favorite solution. Just about every recommendation on this page so far has some merit, listening dials the compass in that much more. DO also search the forums to read about all of these.

[russ69]

If you want to take a giant step and start playing with the big boys, it's time to move to separates. A pair of Quicksilver horn-monos and the best pre-amp you can afford will push your system to places you can only dream of. It's a giant step up.

Thanx, Russ

[Erik Mandaville]

Another option is bi-amping (which I admit can be another can-o-worms). I've been auditioning our La Scalas with a combination of single-ended 2A3s or 300Bs on midrange and tweeter, and a very quiet and clean 60 watt (for me this is very serious power!) vintage Hafler SS amp straight into the woofer, series inductor bypassed. Now granted, there are many unquestionable benefits to active biamping with line level crossovers. That fact notwithstanding, I have seen many examples of users very satisfied (where in fact some manufacturers had recommended) doing this passively rather than actively in order to maintain other carefully tuned elements associated with the crossovers -- such as impedance compensation networks, notch filters, and so forth; where if someone were to decide on an active line level system that didn't have those carefully (of course via measurement, but ultimately and finally listening) features, an otherwise carefully configured balance of driver interaction and response would be defeated.

There was a thread recently contributed by a forum member who switched from just such a formerly very much enjoyed SET amp to another classic valve amp with much more power (say in the range of 20 to 25 watts, which at the end of the day isn't all that huge) If I remember right, he was very, very pleasantly surprised.

[Khornfan]

Thanks, Bob. Good info.

[moray james]

Consider an Antique Sound Labs AQ1003DHT and switch out the 12AU7's for 12BH7's Best regards Moray James.

[Khornfan]

Thanks to all for your suggestions. I would love to listen to some of the various combinations mentioned but there do not seem to be many khorns in Oklahoma. Maybe I can make it to Indy in June and see (hear) something.