Hersey or SF-2

[tpg]

This amp has been regarded quite highly, though you must build it yourself. It is simple, though trust me.

http://www.tubeaudio.com/page23.html

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SoundWise / ProMedia Tech Support / 1-888-554-5665s>

[JasN00b]

that kid comes with everything?

and that amp sounds good?

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I. Love. MUSIC!

[Manuel Delaflor]

Malcolm,

Can you be a bit more specific about the bass issue with your Heresy's? I think that a good tube amplifier will drive them without any stress, probably what you say relates to "weak" (in watts) tube amplifiers.

Now, have you listened your speakers with a Hi End tube amplifier? In a week or two I will buy an Hybrid integrated which uses a tube pre and ss amplification.

I will post my impressions here.

This message has been edited by Manuel on 09-13-2002 at 05:21 PM

[JasN00b]

can someone give me some input on that tube kit TPG suggested?

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I. Love. MUSIC!

[Malcolm]

Manuel,

My preference for a ss amp over a tube amp with Heresys has nothing to do with the amount of power a given amp can put out. I would not recommend them for use with low power SET amplifiers because IMHO they are not efficient enough. But there are plenty of other tube amps that can easily drive them loud enough you won't want to stay in the room with them.

My preference has to do with effect of the difference in damping factor between a typical SS amp and a typical tube amp. Damping factor is the ratio of the impedance of the load (including crossover and cable) to the output impedance of the amplifier. Tube amps typically have an output impedance much higher that that of a SS amp. So tube amps typically have a lower damping factor.

Damping factor affects how fast a speaker will stop moving when the signal is removed. The woofer has quite a bit of mass and is not well damped mechanically. It wants to keep moving after the signal is removed. The air in the sealed Heresy cabinet helps some but is not enough. It has to be helped by the amplifier.

An appropriately high damping factor, say 100 or more, which is typical of a SS amp, will stop the speaker quickly and give the most accurate reproduction of the signal. A lower damping factor will let the speaker continue to move longer after the signal is removed and a less accurate reproduction of the signal. A damping factor of 20 or less is generally considered pretty bad.

A poorly damped speaker is sometimes called "boomy." A good example of the sound of a "boomy" speaker is the subwoofer in many kids' cars. Instead of the thump you should hear from a kickdrum, you get a sound more like a kettle drum. This kind of sound bugs the heck out of me because I used to be a drummer in my younger days and know first hand and close up what percussion instruments should sound like.

Damping factor is less of an issue with the squawker and tweeter because their diaphragms have much less mass than the woofer and can be easily stopped. And my guess is it is less of an issue in designs with horn loaded woofers, like the Klipschorn and LaScala, because the cones are moving far less for the same volume/power and are pretty well damped to start with.

[JasN00b]

so i should go for a SS amp?

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I. Love. MUSIC!

[Malcolm]

The same thing goes for amplifiers as speakers. You need to listen to whatever you are considering and then make a decision.

[Manuel Delaflor]

Malcolm,

Leaving aside all the concepts in your post (which are correct generally speaking), the best bass I have listened in my life has came out of Tube preamps and amplifiers. The theoretical control you mention of typical SS's is simply not there, at least in the sense of replicating the natural resonance, timbre and speed of acoustical instruments.

Last week I learned this when I seriously auditioned (for the first time in my life) some Hi End tube designs from Margules Audio. There was a fairly good SS HK in there for comparison purposes, and I can tell you, the bass in Classical music is simply an horrible mess with the KH. With the Tubes, on the other hand, the bass is spectacularly tight and controlled, one can easily hear that there are several instruments playing at the same time, instead of the blurry mess of the SS.

As you can see, I don't buy anymore any theoretical concept, no matter how well done is it. I choose to believe my ears.

Now, of course, if you talk about really difficult loads (which the Heresy IS NOT), then SS can have some use, but again I will never run an SS without coupling it with a good Tube Preamplifier!

This message has been edited by Manuel on 09-14-2002 at 01:38 PM

[Malcolm]

Manuel,

My preference is not based on experience, not theory.

And, the effect of low damping factor is not a theory. It is easily demonstrated. But, belive what you like. You are starting to sound like an "audiophile."

[Manuel Delaflor]

Malcolm

I know the effect is real, and that difficult loads as Electrostats can be driven correctly with good damping. So, is not that I don't believe in what you say.

My point remains, listening to non difficult load speakers with tubes will render a superior listening experience, the bass will sound "tighter" and far more realistic. No need to argue this point, everyone can have the experience for themselfs.

Hmm and if you said that I sound like an audiophile I expect that you were actually making a compliment! But I don't consider myself as that, because I try not to get lost in conceptual nonsense.

[JasN00b]

can i get a straight suggestion here?

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I. Love. MUSIC!