What makes you build a system around an amplifier?

@robd1

Is this statement from @atmasphere above true?

"At the other end of the range, the speaker is pretty low impedance (1.5 to 3 ohms depending on the position of the Brilliance control) which will cause most solid state amps to be too bright and nothing for it but to turn down the Brilliance control and deal."

That is, if it’s a low impedance speaker, an underpowered (or maybe not enough current) solid state amp will sound brighter?

Yes it is true, but the answer to your concluding question is ’no’. The more the powerhouse amp, the worse this problem becomes:

The comment is regarding a Sound Lab ESL, which is about 30 ohms in the bass and has the impedances stated above at about 20KHz. Like many ESLs, the impedance curve goes from high impedance in the low frequencies to low impedance in the highs, covering a range of about 10:1. If you put a solid state amp on that, it will be bass shy and way too bright, due to the amp likely acting as a voltage source (IOW, can double power as impedance is cut in half). For this reason, you can see that ESLs are generally incompatible with solid state without special measures being taken.

Its important to understand that the impedance curve of an ESL is not also a map of its efficiency (they are quite unlike a box speaker in this regard). They tend to have the same efficiency from lows to highs. Their impedance curve is based on a capacitor which is the basis of their operating principle.

Do you even listen to music?

:) I have about 8,000 LPs and not one is Nina Simone, so yes...

Many tube amps do not have a decently flat frequency response under real loads (just look at the Stereophile graphs - they are often horrible). Often their response is tweeked to appeal to the subjective audiophile who thinks his hearing can beat any audio analyzer from the likes of Audio Precision or DScope.

This statement is not accurate. Most tube amps are intended to act as voltage sources and so do quite well on such tests. But many tube amps are not intended to be voltage sources out of intention- and of course part of that is they are not intended to be used with speakers that expect that amp to be a voltage source. The 'tweaked' statement in the post is entirely false. This is a topic worthy of its own thread.

The difference does pose the question what the aim is of good audio equipement: the (impossible) recreation of a live event, given the physical limitations, or something else.

The best model I've come up with to describe how a two channel system works is to imagine that the room and its stereo is a sort of time travel machine ala Dr. Who, that will allow your room to be 'grafted' in the performance space of the original event. For this reason you cannot hear what is around you, but you can hear what is in front of you just as if your room was hovering in space in front of the musical event.

Imaging? Relaxed presentation? Bass juiciness? Best presentation of Nina Simone you ever heard?

Yes, yes, yes and who??

When I have the right amp in the system, its a lot easier to convince my girlfriend to spend the evening spinning LPs...

@bdp24 thanks!

Generally speaking, the amp/speaker interface is a very important part of the game. OTLs in general like to see higher impedances (although the speaker impedance curve doesn’t have to be flat), and the same is often true of SETs.

First Watt solid state amps are also best used with speakers of more than 4 ohms. They don’t make a lot of power either, so you do best with them if you have an easier speaker to drive- 95 db or more.

I don’t agree that all ’well-designed’ amplifiers sound the same- far from it. A lot depends on the goal of the designer! For example, our amps are very wide bandwidth and low distortion, but they don’t use feedback, and that is with intention. This was to avoid the distortion caused by the feedback system itself, and the result of that was that we have to be quite selective about what speakers to use with the amps. But the upside is as far as we can tell, this allows us to get a lot closer to the music itself.

I’m pretty sure that if you talk to an SET designer, you will find that they say something quite similar, and if you read Nelson Pass’s articles about the First Watt amps, you will see the same thing espoused. I’m not saying that there is only one way and its our way, what I **am** saying is that making an amp that is a perfect voltage source is not the only way and that there are advantages to avoiding that approach.

This means that you can’t just buy a speaker and expect that any amp will work with it. In fact, the idea of the amp being a voltage source for flat bandwidth (which I call the Voltage Paradigm) really only works with box speakers where the impedance curve is also a map of the speaker’s efficiency. There are a number of speaker technologies that don’t fit that model and as a result, don’t work with that kind of amplification.

You can read more about this topic at this link:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

Roger Modjeski of Music Reference is now offering an ESL of his own design and build, with a dedicated direct-drive tube amp---the amp has no output transformer, the ESL no input transformer, the ESL panels driven directly by the output tubes! THAT is the ultimate, perfectionist way to do it.

Its a way that can yield excellent results but I would not call it perfectionist. If you encounter any circumstances that mean a change is needed (such as more power, want deeper bass, etc.) you have to start over from scratch.

You **certainly** without reservation want to start with the amp first!

The reason is simple: you might have a preference for a certain kind of amp, for example, tube or solid state. Maybe you've heard how much better an amp can be if it lacks feedback. That sort of thing.

If you start with the speaker first, you may be painted into a very expensive corner. Here are some examples:

If you start with the Sound Labs because you fell in love with the speed, delicacy, bandwidth and sheer convincing qualities those speakers have in spades, you're screwed if you also only will deal with solid state. You will never get the performance out of that speaker! The speaker has a 30 ohm peak in the bass which is easy for a tube amp and hard for a solid state amp (IOW overall weak power with weak bass). At the other end of the range, the speaker is pretty low impedance (1.5 to 3 ohms depending on the position of the Brilliance control) which will cause most solid state amps to be too bright and nothing for it but to turn down the Brilliance control and deal. This is the case with most ESLs BTW.

If you happen to prefer tube sound, you will have a very difficult row to hoe if you get Magnaplanars. That speaker is very revealing, and there are only a handful of large tube amps that really make the bandwidth and power that are both needed for that speaker to sound right.

I can go on, but the point is very obvious- its a foolish act to get a speaker first and then discover that its incompatible with the type of amplification you prefer. You'll have to start all over again, which sucks.