Amp required for cornerhorns

[fenderbender]

i drive my klipschorn whith rouge audio m-150 and luxman cl360preamp

i drive my klipschorn whith rouge audio m-150 and luxman cl360preamp

i drive my klipschorn whith rouge audio m-150 and luxman cl360preamp

I can't speak highly enough about rogue gear. Made and assembled in America

High build quality, and sounds great!!!!! I love even the entry level Atlas driving klipschorns. I've had and auditioned amps costing five times $$$$ and the rogue gear always bested it. very tight fast bass for tubes, and sparkly mids

.

[Guest " "]

I would go with SE in the 10 to 20 WPC range. lots of nice 6l6 new production kits on ebay, Buying new skips all the recapping and hum troubleshooting issues. You didn't say what year your khorns are? latter models have bi-wire capability, If you have that, I would put the SE amp on the HF section and use an SS amp in the LF section. You would need a LF/HF crossover solution which I would go with a passive one.

[Don Richard]

So whats that kicking me in the A$$..... when I listen to my low power system. (10 watts push/pull on LF and 5 watts on HF) playing Jub/K402 in an acoustically treated room.

Uh, a push-pull amplifier is not an SET.

In all my experiences 5 watts on 104db efficient Khorns in a 2600sq ft room that was reasonably treated for 2/3 ch music reproduction could play louder than anyone cared to hear for more than one-song.

2600 square foot room? That's about 30 feet by 80 feet dude. Most folks' houses are not that large. And 5 watts is too loud? Oooookaaaay.....

. I also demoed with a highly modified Hafler DH200 (110 watts SS) amp as well as Dynaco MKIV (40 watts P/P tube) amps and the 2A3 SET always ended up the preference...unless they were just lying to me..

Since they are friends, they were probably trying to be kind[] The validity of such impromptu "tests" is highly suspect and such stories are no more than anecdotal.

Yet many who would post against them have extremely limited experiences with SET amplifiers running high quality/ high efficiency loudspeakers.

Been there, done that... back in 1969 or so.

[mikebse2a3]

Uh, a push-pull amplifier is not an SET.

Don I respect you and like reading many of your post/ideas but come on Don you and I both know my comment was directed at the idea of low power amplifiers not being able to supply the drive needed for satisfying/accurate bass. One listen to my present system (or my past based 2A3 SET driven KHorn system) makes that idea..[bs]

2600 square foot room? That's about 30 feet by 80 feet dude. Most folks' houses are not that large. And 5 watts is too loud? Oooookaaaay.....

Sorry for the mistake here, should have been 2600 cubic ft.

Since they are friends, they were probably trying to be kind The validity of such impromptu "tests" is highly suspect and such stories are no more than anecdotal.

Yep..people would just have to take my word for it unless you had been there and thats why I strongly advocate people actually experience all these options we have and not just believe what they read..! I never recommend anything to anyone without at least trying to understand where they have been, where they are and where they want to go in this hobby.

I'm not going to get dragged into one of these SET/Low Power merry go rounds that happens way to often and really are pointless and a waste of time but I will state again IMHO:

"Yet many who would post against them have extremely limited experiences with SET amplifiers running high quality/ high efficiency loudspeakers."

miketn

[jannegard1]

hello fenderbender

yes rouge audio m-150 is a good tube amp i have kt88 6550 tubes but i can use el34 just setting the bias

love this amps

[mike stehr]

Yet many who would post against them have extremely limited experiences with SET amplifiers running high quality/ high efficiency loudspeakers.

Been there, done that... back in 1969 or so.

I'm curious, and not at all concerned about whether or not a single-ended triode amplifier has adequate bass.

But what sort of a single-ended triode amplifier did you have in 1969? Or was it a single-ended amplifier using a Pentode or Tetrode? Strapped for triode? Was it a homemade amplifier?

[lyfguard1]

I've never tried a SET amp with my Khorns, but I originally tried a couple of not worthy solid state amps and then tried tubes via a Scott 222D. The speakers sounded great with that amp, but it seemed to run out of gas at about 12 o'clock and I sometimes like things a little louder. I'm currently running mine with a Pioneer SA-9100 amp that is fairly tubey sounding, and it sounds good ... but it's just not as good as tubes. I think something like an ST-70 would be perfect for them. I've been lookiing at the kits from Bob Latino with much lust, and am hoping I get a decent tax return this year and maybe I could swing it. The Scott 222D is now powering my Chorus I's, and they sound beautiful - even better than the Khorns really - and that's not right. I'm curious if anyone is using an ST-70 with their Klipshorns and what kind of results they might be getting.

[Marvel]

I'm curious if anyone is using an ST-70 with their Klipshorns and what kind of results they might be getting.

I think Mallette uses an ST70 with Khorns. I have an ST70 but no Khorns...

I use 2A3 amps with my LaScalas, and can rock much louder than my ears like.

Bruce

[Chris A]

I'm currently running mine with a Pioneer SA-9100 amp that is fairly tubey sounding, and it sounds good

This is the reason why I suggested the First Watt F3 amp above.

The writeup on this amplifier type (FET amps - not BJT SS amps that are uniformly being compared to SETs and push-pull triodes and pentodes) by Nelson Pass should scratch most folks' itch here on "tube sound" without the requisite low reliability/mean-time-to-maintenance intervals and long, long, long warmup times.

I have but one question here for all the tube amplifer folks: what is the output impedance of these tube/valve amplifers?

If the amp's output impedance is much above ~1 Ohm for any Klipsch Heritage speakers that are horn loaded (any drivers on the speaker), I believe that you've got a real problem in introducing measurable distortion in small listening rooms--such as most everyone's home listening rooms. If the amp's output impedance is at or below ~1 Ohm, then the amp/speaker system has a chance of reproducing only that which is being input via the preamp/source material.

Chris

[fenderbender]

"This is the reason why I suggested the First Watt F3 amp above. "

My experience with the f3 was not good at all. I auditioned one on my khorns in my home for a week a few years back. The bass was fast and tight but the upper mids were smeared and the highs were shrill. I couldn't listen for long with out fatigue. I guess that it might have had some interplay with the ALK x-slopes , I never tried them with the AK-3 xovers.

perhaps a tube front end would have smoothed things out. It was a dealer Demo for a great price but I wasn't interested. I even tryed the pass labs monos ( I forget which model) and they were worse!!! I know the F-3 is a great amp. Just didn't work on my system in my room. That doesn't mean it won't work for you

Cayin makes a great 80 watt hybrid int. ) tube front, SS amp) that sounded amazing.

for "tubey" sound a restored Mcintosh mc2505 works really nice. I really regretted selling the one I had

IMO khorns are a funny beast.....and not like most speakers.... They are very particular what you feed them and how your room is set up and treated. My best advice is to try to audition different amps. I know this is next to impossible but you really need to hear them with your ears.

[Don Richard]

But what sort of a single-ended triode amplifier did you have in 1969? Or was it a single-ended amplifier using a Pentode or Tetrode? Strapped for triode? Was it a homemade amplifier?

When I was in college a friend who worked as a projectionist at a movie theater showed up with an old mono amplifier he found there. It was in bad shape and all of the caps had to be replaced. The resistors appeared to be pre WWII and the output tube was a direct heated triode that looked like an 807 transmitting tube without the plate cap. We hooked it to an Altec VOTT and played music through it. It was noisy and ran out of steam rather quickly with a lot of distortion.

The OP wrote in asking for advice on an amplifier for a Khorn. I don't think he wants to biamp or get into anything too complicated. SETs are not a good choice for a general purpose amp to use on cornerhorns, they are an acquired taste.

There are many amplifiers that would work well with cornerhorns. Choose a low noise amp as horns are sensitive and will reproduce any hiss that is present. 25 to 100 watts is plenty of power and there are numerous solid state and tube amps that fill the bill. Don't overlook recievers as there are a number of them that will do just fine driving Khorns. Don't overlook the used market. Some of the best bargains are in used equipment and repairs can be inexpensive.

[Chris A]

My experience with the f3 was not good at all. I auditioned one on my khorns in my home for a week a few years back. The bass was fast and tight but the upper mids were smeared and the highs were shrill. I couldn't listen for long with out fatigue. I guess that it might have had some interplay with the ALK x-slopes , I never tried them with the AK-3 xovers.

perhaps a tube front end would have smoothed things out. It was a dealer Demo for a great price but I wasn't interested. I even tryed the pass labs monos ( I forget which model) and they were worse!!! I know the F-3 is a great amp. Just didn't work on my system in my room. That doesn't mean it won't work for you

That's interesting, because this amp is clearly superior, in my humble opinion, driving my K-402s and TAD TD-4002s. Crossover performance (including time alignment) is critical to performance. Did you time align your drivers? All you have to do is to pull the tweeters out of the cabinets and mount on small baffles/stands, then align them at the back of the cabinet just over the midrange K-55 driver front face directly below it.

Chris

[Chris A]

SETs are not a good choice for a general purpose amp to use on cornerhorns, they are an acquired taste.

I believe this is an understatement, but that's just my opinion. The worst amps that I have ever heard connected to my cornerhorns were Bottlehead Paramount 300B SETs - they were awful, unspeakably awful on any tap setting and using any time delay.

They were also assembled, tested, and then sold to me by "Doc", i.e., the founder of Bottlehead himself...

Chris

[fenderbender]

My experience with the f3 was not good at all. I auditioned one on my khorns in my home for a week a few years back. The bass was fast and tight but the upper mids were smeared and the highs were shrill. I couldn't listen for long with out fatigue. I guess that it might have had some interplay with the ALK x-slopes , I never tried them with the AK-3 xovers.

perhaps a tube front end would have smoothed things out. It was a dealer Demo for a great price but I wasn't interested. I even tryed the pass labs monos ( I forget which model) and they were worse!!! I know the F-3 is a great amp. Just didn't work on my system in my room. That doesn't mean it won't work for you

That's interesting, because this amp is clearly superior, in my humble opinion, driving my K-402s and TAD TD-4002s. Crossover performance (including time alignment) is critical to performance. Did you time align your drivers? All you have to do is to pull the tweeters out of the cabinets and mount on small baffles/stands, then align them at the back of the cabinet just over the midrange K-55 driver front face directly below it.

Chris

hey Criss

the first watt amps are first rate products, I heard them and pass labs at my dealers showroom through different speakers( memory fails) and they did a nice job. He knows I'm a Klipsch guy and gave me his F-3 demo to try on my khorns to get my opinion. Now the x-overs I had were ALK extream slopes - not active covers so I could not do any adjustments

It was honestly the first time I heard my khorns sound " honky". Again may have been the way the x-overs are set. Could be my room?? Just that I've had several diff amps and never experienced that "honkeyness"

[Chris A]

It was honestly the first time I heard my khorns sound " honky". Again may have been the way the x-overs are set. Could be my room?? Just that I've had several diff amps and never experienced that "honkeyness"

By the following diagram, "honkyness" is in the range of 450-800 Hz:

This range is strongly affected by ceiling/floor bounce of the K-400 and K-401 horns losing their polar control below ~1.5 KHz and painting your ceiling and floor with excess energy that bounces back to your listening position(s).

My guess is that your listening room has 8' (or lower) ceilings with little to no acoustic treatment, maybe even hard flooring--such as tile, etc., and maybe a rising in-room midrange response due to your steep-slope crossover caused by lower impedance of the K-55+crossover network in this region. Another issue is if the Khorn bass bin is padded down a little too much by the crossover, making the midrange sound "honky". Al K's crossovers reduce the overlap between midrange from the bass bin more, thus exposing the K-55/K-400 extreme low frequency performance more.

Additionally, a strident sound is usually caused by increased FR and driver/horn ringing issues at 8-12 Khz, which is also in the range for increased sibilance. One of the things that Al K's crossovers do is to curtail K-55 overlap with the K-77 tweeter, and what you then hear is mainly the T-77 unmasked, which can be a bit strident if it isn't padded down a bit.

Is any of this true?

Chris

[fenderbender]

Chris.... Oh well we've hijajacked this thread... LOL

My room is a big open space carpeted with 10 foot ceilings, that opens up to a tiled kitchen about 20 ft from where the klipschorns were placed..... no matter what amp I used I have always had resonance problems from the mid bass down, but thats a factor of cheap Florida new construction..... had a tone generator disk that ran through the whole spectrum and tried isolate some of the problems, but short of ripping down the dry wall and replacing the metal studs and replacing all the windows, I had to live with what I got. One of the reasons I sold the klipschorns....

"Additionally, a strident sound is usually caused by increased FR and driver/horn ringing issues at 8-12 Khz, which is also in the range for increased sibilance. One of the things that Al K's crossovers do is to curtail K-55 overlap with the K-77 tweeter, and what you then hear is mainly the T-77 unmasked, which can be a bit strident if it isn't padded down a bit." This probably was part of the reason..... My dealer told me something along these lines, but i'm not very good at tech speak.......

[Chris A]

Chris.... Oh well we've hijajacked this thread... LOL

I'm not so sure that we've hijacked it since the OP needs to know that there are other factors involved than just amplifier+speakers.

 

Thanks for answering my strange questions/soothsaying guesses. I'm trying to practice correlating amp/speaker issues with acoustics and crossovers, and that subject can get a little complicated. But I did want to highlight that there are also things that can be done to deal with amplifiers: just like many folks EQ their speakers to their rooms, I think that there is a lot of "EQing via amplifier". Some amplifier/speaker issues can be resolved simply by doing a small amount of EQing to flatten things out a bit and compensate for room acoustics, such as the now famous "collapsing polars" of the K-400 and K-510 horns.

Note that I'm running active crossovers (Dx38s) that correct for the controlled coverage K-402/compression driver response drop vs. frequency anyway, and it's easy to change the settings that I have to compensate for resulting FR bumps and tilts when using new amplifiers. Roy Delgado calls this "salt and pepper EQing" and it takes only a few seconds punching in updated settings to do it.

The K-402s don't have collapsing polars but they are sensitive to how close they are located to the side walls. I've found side wall proximity affects stereo imaging strongly with the K-402s, but not their EQ.

 

no matter what amp I used I have always had resonance problems from the mid bass down

Actually, you do know that Khorns have a couple of FR bumps in the 100-200 Hz and 300-400 Hz areas. I've had to EQ down my Jub bass bins fairly strongly to correct for this "too-small bass bin mouth" response hump. Its the light green trace in the following figure that I had to tame to achieve the dark green line. The red line is the uncorrected in-room response of the SPUD tapped horn subs in the corners behind the Jubs. The dark green line is the total response at the prime listening position(s).

 

 

Here is the anechoic Khorn bass bin plot (the black trace) overlaid on the normalized Jub bass bin plot (red trace).

Chris

Edited September 3, 2015 by Chris A

[tube fanatic]

I have but one question here for all the tube amplifer folks: what is the output impedance of these tube/valve amplifers?

If the amp's output impedance is much above ~1 Ohm for any Klipsch Heritage speakers that are horn loaded (any drivers on the speaker), I believe that you've got a real problem in introducing measurable distortion in small listening rooms--such as most everyone's home listening rooms. If the amp's output impedance is at or below ~1 Ohm, then the amp/speaker system has a chance of reproducing only that which is being input via the preamp/source material.

Chris

It isn't unusual for SET amps, which typically don't use any negative feedback, to have an output impedance of 2 or 3 ohms. With speakers which have a large variation in impedance across the audio band this is potentially significant. I say potentially because much depends on how loudly you listen (which determines just how much voltage the amp is called upon to produce.) Adding some negative feedback can reduce the output impedance thereby creating a better match with such speakers. Many users of single ended tube amps enjoy listening with single driver speakers which have a fairly constant impedance across the audio band. My experience with SETs and K-horns, Cornwalls, and La Scalas is that they work quite well if the levels at which they are listened to don't tax the amp too heavily. Under those conditions the sound they produce can be magical in terms of soundstage size, imaging/detail, and the bass, while not the same as what is produced by a solid state amp, is full and rich without being boomy or in any way objectionable.

[Chris A]

It isn't unusual for SET amps, which typically don't use any negative feedback, to have an output impedance of 2 or 3 ohms

I've seen examples of tube amps with 15-30 Ohm output impedance, all of them are SET amps with no feedback. It is feedback that lowers the output impedance, but SETs can't really do feedback because they don't have a lot of forward-loop gain to use feedback. It's a problem with triodes themselves. I've also noticed that the offending designs often do not post their output impedances in their specification lists. This isn't very nice practice, IMHO, and should be a red flag when one is looking at prospective amplifier designs.

The effect of having an output impedance that is the same as or greater than the load is not at all desirable. The rule of thumb for linear system design is 10:1 ratio of load input impedance to amplifier output impedance in order to not interact with the load in a non-linear way. The effect of the interaction is a "reverb effect" in-room. The effect is much worse with high-efficiency horn-loaded speakers that can be run backwards via in-room acoustic reflections.

Nelson Pass's First Watt FET amps list their output impedances. The F3 single-stage JFET amp uses negative feedback to hold down its output impedance to ~1 Ohm. If the F5 was still available (it isn't...), I'd've bought that one instead.

Chris

[tube fanatic]

It isn't unusual for SET amps, which typically don't use any negative feedback, to have an output impedance of 2 or 3 ohms

I've seen examples of tube amps with 15-30 Ohm output impedance, all of them are SET amps with no feedback.

I've never encountered output impedances that high! The questions about why SET amps do what they do have been raging for longer than I've been in the field (and that's roughly 5 decades!) It brings to mind a review of the Cary 300B which Stereophile ran back in the 90s (just found it- here's the link: http://www.stereophile.com/integratedamps/398) In spite of the horrible measurements, the amp sounded wonderful. If you get the chance, read the whole review, and especially take a good look at the measurements. I can't explain why so many SET amps sound amazing. I've designed/built dozens of SETs (without any negative feedback), and SEPs (with enough negative feedback to keep the distortion very low) for people over the years and frankly, given the right choice of speaker, I prefer the sound of the SETs. It's a question which is unlikely to ever be answered and gives a great deal of credence to the often quoted statement, "if it sounds good to you, it is good!"