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Reckon we need a new forum....


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The Tube forum (aka - MobileHomeless advisory).

If we dont get one we should rename this one. We've all gone tube crazy and everyday my Accuphase E211 moves a step nearer to the door (its relegated to rear channel duty only now - rather a waste of $2,100 worth of amp).


2 * Heresy 2 (mains)

2 * Homemade horn speakers (rears)

1 * REL Strata 3 sub

Accuphase E211 amp.

Tube monoblocks with separate pre-amp (solid state).

Marantz CD6000 player

Sony NS900 SACD/DVD player

Stax Headphones

Humax 5400 digital satellite receiver

Sharp Video

32" Sony flat screen 16:9 TV

Mogami interconnects

Silver Synergistic speaker cable

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kh, aka mobilehomeless, is definitely onto something.

Horns & tubes are a match made in heaven. Do not look at specifications...let your ears tell you what is right. If it sounds truly natural & harmonically correct, then it is!

The problem with reviewers & specifications is that they compare tubes vs. transistors and solid state always measures better. Obviously, if it measures good and sounds bad, they're measuring the wrong thing! Likewise, if it sounds good and measures bad!

Audiophools do not realize that the most linear, naturally distortion free (no negative feedback required) amplifying device ever created was a vacuum tube (specifically DHT (directly heated triodes) created in the 1930's). Also, simple tube amplifiers require about 2-3 gain stages whereas solid state requires about 14. Just think what happens to the audio signal? IMHO, simpler is better!

Don't get me wrong, I like solid state gear (it's very efficient) but I prefer triode tube gear when it comes to very efficient speakers. Save the big hog transistor gear for inefficient speakers.

As always (whatever you have & like),

have fun & enjoy,


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Thanks, Maxg. That would be a horrifying thought to some here!

I think a forum called Tubes and Klipsch would be an interesting addition. To be honest, the only reason I am HERE at all is the search for excellent speakers that were efficient enough to be driven by very low power amplification. Pete made a good point. I have found the less stages and parts you have in an amplifier, the closer one seems to get to the essence of the music. And the Directly Heated Triode is perhaps one of the simplest of all devices there is. I am also a fan of the DHT. And DHT SET amplification, which endeavers to leave the entire audio signal intact all the way through the chain, is the simplest of all forms (and with when you take away the negative feedback, you have just jumped up another level of uncorrupted signal/sound). The parts count in one of these amplifiers would just amaze you. There simply is hardly anything there! Just a handful of parts!

On the other hand, these types of amps do very poor on speakers with impedance dips or that are relatively mediocre in the sensitivity deparment. While they are very pure sounding, they sure do not feel at home with an 86dB speaker with a impedance dip at 2 ohms in the low end! Given such conditions, or even conditions a bit less stressful, and the Single-Ended Triode amp can sound like it would not make the volume of your clock radio (although this is also up for grabs as a 90dB speaker with a benign load WILL sound pretty damn good with 3.5 watts...it just wont SING - the clock radio retort is a gross example).

But each form of amplification has its good performers. A good circuit in a solid state amp can yield good results. I have been enjoying this Monarchy Audio 25w Class A amp (no global feedback) the past week. It can get you going on these Cornwalls! Yet still, when you move to tube amplification, even well designed push pull, you see the difference.

I just think it's great that others here are trying tubes out for the first time, and really enjoying the music. Ultimately, beyond the hobby status, it IS the music that really matters.


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Interesting point abouit impedance dips Mobile. I have always wanted to try out some ESL speakers but they are legendary for their dips.

I imagine that these would rule out a tube amp and that therefore I will be sticking with the Heresy's for a while longer.

On the other hand Quad do make tube amps to go with their 988/989 speakers. The only problem is that on the demo I said to the salesman:

"That's great - sounds wonderful - now lets try them with some volume."

And he replied.

"We are at the maximum volume now!"

unfortunately - he said it - he didnt have to shout it, he could almost have whispered it - from another room!!

And Mark,

Yes - there are people who listen to Heritage speakers with SS amps. I was one of them till very recently. Maybe it is a mistake - but it is a commmon one.

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Yeah, the intrest in tubes aroung here is exploding. I don't imagine, once approved, that it would take the web master more than 10 minutes (if longer, sorrySmile.gif) to put up a tube section. maxg, your post, so post this under the web site comment area, and hopefully the webmaster (or mistress?) will obey our mighty command. Any other topics of interest we want? We should be able to post pictures DIRECTLY to the Klipsch server (or host) as I want to send pictures and not build a site for it. Come on, even if they are using Ultra160 SCSI hard drives, they are not that expensive and they could limit pictures over a certain size, say 250k, so why not!?

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You are right of course with regard to the varying impedance being a problem upwards as well as downwards.

I mentioned the downwards impedance as this is the major problem with the ESL's I have tested.

Using the Final 0.3 for example we managed to bring even my SS amp to a grinding halt. That speaker has a truely wicked impedance curve that drops well below 2 ohms (it starts at 4 and falls off from there). According to the technician I spoke to he indicated the impedance could fall as low as 1.1 Ohms.

There are precious few amps aout there that will go that low. A friend of mine has one - The Electrocompaniet - 50wpc/class A.

That baby goes as low as 0.5 ohms according to the specs but unfortunately 50 wpc aint enough for the finals (we really neeed 120 wpc and up to get them going - and 200 wpc plus to really make them sing).

The quads are less dramatic but still get perilously close to those below 2 ohm figures that kill most amps.

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mdeneen is definitely correct here. Some amps also do better at different taps depending the outputs as well. I tried my Jolida 302B on all sorts of speakrs, and it generally did better using the 4ohm tap. On the EICO, it really sounds the best when you try to match the ohms with the speakers you are using. Still, nothing is set in stone...

But with most SET amps and tube amps in general, it is the dips in the impedance that kill the ability to drive the loads. The low end of impedance dips is SOOO much more difficult to deal with; and as mdeneen said, the SET amp with 3.5w and ZERO feedback can run into problems with dips below 4ohms.

Yet this is why the 2A3 tubes is such a good SET choice. It has a relatively good damping behavior without feedback. SET amps are also not fond of elaborate complex crossovers in speakers. I have found my old Cornwalls with the original type B crossovers to be really great. I might be taking delievery of a rear loaded horn design using a Fostex full range driver with no crossover. I have yet to try this and am interested. OF course, the differnce in low end will be serious ..but I really want to try the single full range driver approach.


ps - Mdeneen, what is your amp anyway? I dont rememeber what you said it was. You mentioned it in past.

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Deang, so you got a Superamp coming?

I've had mine since early January, along with the AE-3 preamp and a "new tube 4000" cd player ... however, I haven't gotten past the break-in period since they're all waiting on my "Khorn resuscitation" project to be finished (hopefully this weekend). I'm down to the last coat of stain on the second one, followed by a couple of poly coats, the insertion of ALK's magical board, and reassembly. Anyway, I'm really eager to fire it all up (along with the obligatory christening with scotch).

Mobile's been kind enough to put up with my dumb questions about upgrading the stock Chinese tubes that the AES product comes with, and I'm eager to try them out.

Whatever you come up with for magical tube combos, let us know. I'm shopping for the 6NS7's for the AE-3 right now. Mobile recommends some of the older vintages, and has a few secrets about "his favorite". He won't tell me what it is because they've been hunted to virtual extinction.

Anyway, post your review of the amp after you receive it!


If you don't like what is coming out, you wouldn't like what is going in." -PWK-


Klipsch 1968 ALK Cornwall "II"s (LF/RF)

ALK Belle Klipsch (Center)

Klipsch Heresy (RR/LR)

Klipsch KSW-12 sub

Sonic Frontiers Anthem AMP1 (driving Cornwalls)

Sonic Frontiers Anthem AMP1 (driving Heresy's)

Denon AVR-4800

Toshiba SD-3109 DVD

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There have been a few speakers that make the Final's impedence look like a friendly load.

Probably the most infamous was the Apogee Scintilla. This was a full range speaker that used ribbon drivers for the bass, mid and treble. It's resistance at some points in the upper bass and lower midrange hit 0.1 ohm, and it was extremely inefficient on top of that. Hitting anything over about 90dB required massive amounts of top quality current dumping solid state power. There's an Audio review from December of 1985 posted on the Apogee user's website at http://www.apogeespeakers.totalserve.co.uk/reviews/scintilla_audio_dec1985.htm

Just to give you an idea, Audio biamped these things with four Krell amps, two KMA-100 driving the midrange and treble and two KMA-200 driving the bass panels. The KMA-200 was rated by Krell at 1,600 watts into 1 ohm. Audio measured peak output levels of 98dB at amplifier clipping.

Using four of the biggest amps available at the time and pushing them to the limit, the Apogees played as loudly as a Klipschorn or La Scala or Belle will play at 1/4 watt.



Music is art

Audio is engineering

Ray's Music System

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The tube amp's response to impedance is one of my concerns. A K-horn's impedance varies from 4.5 ohms at 55 Hz to 42 ohms at 2155 Hz. My La Scalas will be about the same.

Which tap do you use for that?

Heresies hit 70 ohms in the midrange and Cornwalls probably get up to 48 or 50 ohms.


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John, from everything I have heard and read about the Khorns, and experienced first hand with the Cornwalls, the Klipschorns do GREAT with tube amplification. I mean, it is one thing to wonder about the correct impedance for optimum matching, but when it comes right down to it, the Klispchorn and LaScaleas are EXCELLENT candidates for being driven by not only push pull, ultralinear, but Single-Ended tubes as well. If you have not tried tube amplification with your LaScalas you really should. Guys that I have shared email with have loved valves on their LaScalas. Hell, the average push pull amp would not even break a sweat with the beasts. Run them on a 4ohm tap...run them on 8ohm...whatever....try it out. The point of the matter is simply that the Klipsch Heritage series speakers present FAR FAR easier loads then 95% of the average speaker out there. Simply put, it is NOT a difficult load. Some may prefer solid state for other reasons but tubes surely work VERY well.

The Heritage series just seem to go hand in hand with tubes, especially with the mid and tweet horns. Just drop by your local sound goon hut and ask to audition a quality tube amp of some sort. Although I am slightly more in favor with the DHT, any well designed tube amp would do very well with the extremely sensitive LaScala. I have had the opportunity to compare a few completely different topologies over the last few weeks: PP Williamson tubes 14w, Single-Ended Triode at 3.5w, and Class A, zero Global Feedback Solid state 25w...all on the Cornwall I with the older Type B and Alnico on the mid/tweet. Of the three, the Single Ended Triode amp definitely came in first place in overall musicality and even bottom end control. It is an amazingly musical match. The push pull williamson design 14w EL-84 amps also did VERY well and was very soulful with power to spare. IT drove the CW to insanely loud levels (as did the 2A3, actually). The solid state Class A Monarchy Audio amp also did nicely but actually came in third if looking at total synergy and musicality. On the other hand, it actually did quite well as well and I was able to enjoy it. But one of the lessons here is that the Klipsch Heritage really do VERY well with tube amps as almost anyone on this board will say.

In using my 14w push pull amp, I have found the 8 0hm taps to actually sound the best with my Cornwalls. The 4 ohm tap worked fine, but I felt it was just slightly more grainy. On all the other amps, the 8 ohm taps have worked very well.

The best thing to do is to give it a shot and try it for yourself. Although I have enjoyed my time with Ed's Class A solid state amp, it has done nothing to diminish my love for tubes with these vintage Klipsch.


Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point

CD Player Rega Planet

Preamp Cary Audio SLP-70 w/Phono Modified

Amplifier Welborne Labs 2A3 Moondog Monoblocks

Cable DIYCable Superlative / Twisted Cross Connect

Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover

system one online / alternate components / Asylum Listing f>s>

This message has been edited by mobile homeless on 02-15-2002 at 11:44 PM

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Something to take into consideration when matching a speaker to a tube amp is how the load changes the loadline on the output tube(s). Especially in the no-feedback applications, the slope of that line has an impact on linearity.

One thing that can be done with 8 Ohm (nominal) horn speakers, because they are so efficient, is to attach them to the 4 Ohm output transformer tap, and then add a 32 Ohm resistor at the 16 Ohm tap. With this setup, the output tube sees only half of the impedence change/frequency of the speaker and the tube load line remains optimized. At the same time, the speaker sees a lower impedence source. I've rewired my Heath W5M in several different configurations, including stock, set, and no-feedback class A push-pull. In all cases the configuration I described provides a cleaner sound.

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Perhaps so, although they do drop the impedance to 4 ohms, although perhaps a flatter response. Personally, I find the original Type B with the oil caps in my Cornwall to be extremely smooth, musical, and detailed with good tube amplification - running at 3.5w with MagneQuest DS-025 ( http://www.magnequest.com/025.htm ) I don't hear any frequency problems. There is amazing low end control and very extended highs sounding unbelievably natural. The 100hz down sounds more natural than with the Monarchy Audio Class A SM-70. No measurements to give this proper validity, just comparing with music with lowly ears conected to skull contents. Although I have access to all the parts to make the comparable ALK unit, I have felt no desire to do so except to perhaps compare someday.


This message has been edited by mobile homeless on 02-17-2002 at 02:09 PM

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