© Ernest Ruiz. 2007

This article is the result of all the messages I have been receiving all along these years from all Audio Nirvana readers asking question about what kind of speakers can be combined with tube amplifiers. In the last years many audiophiles have bought this kind of amplifiers and sometimes when they use them with their speakers, they find that the results are not as good as expected. As we have said before in these pages (see I want a tube amplifier!!) or in the site's forum, it's very important to be careful when combining some speakers with tube amplification. This kind of amps have less power than solid state amps and so they need from the user an extra work to find the right speaker to use with them. If with a solid state amplifier we can use almost any kind of speaker, with tube amplifiers we have to take care of this aspect. As you can imagine the right combination not only depends on the qualities of the amplifier and the speakers, but if both parameters match we could have the needed success. There're many other things to be aware of, for example the speakers impedance, the damping factor between the speakers and the amplifier, the listening room where the system will be used, the kind of music to listen to, etc. On the other hand, we don't want with this article that you get obssesed with its subject, the speaker-amp combination, or that you run to your hifi dealer to ask bizarre questions about it. In fact the amplifier we have selected for this audition has revealed itself as a great performer with all the speakers selected, and we are sure that other amps with similar specifications would perform as good as this. We only want show you or to point some aspects about mactching the right speakers with the right amp. Also we want to show you some speaker models that you could have in mind when thinking about speakers for tube amps, but without forgetting that the last word when purchasing any hifi component is always yours.

For this article we have had the collaboration of the Barcelona's hifi specialist Pont Reyes that we visited in 2003 to see the products made by Atoll and Triangle (see Atoll Electroacustique and Triangle at Pont Reyes). We would like to thank Pont Reyes, specially Sergi, Fran and Carles, for their help and to allow us to use their excellent installations and systems for this audition.

With all these questions in mind we contacted Pont Reyes to set up the audition. Among all the equipment they distribute, we selected a system with the following components: a Prima Luna Prologue One integrated tube amplifier, a Musical Fidelity A5 CD player, Van den Hull Magnum Hybrid speaker cables and Transparent DLink 100 interconnects. The heart of this system, that was selected specially for this article, was the Prima Luna amplifier. The Prologue One is and integrated tube amplifier in push-pull configuration that delivers 35 watts per channel by means of four EL34 power tubes and 2x12AX7 and 2x12Au7 preamp tubes. This amplifier has been very well accepted by audiophiles around the world and for this audition it matched exactly what we had in mind: good build quality, a classic configuration with enough power to be combined with modern speakers and a reasonable price.

With the system ready for the audition we choosed different speakers that were considered suitable for the amp. All the speakers, except one pair, were bookself units and their price was in the needed range, except slight deviations. The listening conditions were the same during all auditions. Now, let's describe each speaker and our opinions. The descriptions are shorter than usual due to the number of listened speakers and to the objective of this article.

JMLab Profile 908

The JMLab Profile 908 are 2 way, front bass reflex speakers. Their sensitivity is 89db/1w/1m, the impedance is 8 ohm, the maximum power handling is 90 watts and the frequency response is 50 Hz-30.5 kHz. Their price is 1700 €. The finish is very good. They have a curved shape as many other speakers that are available in the market, to avoid unwanted internal sound reflections.

The JMLab have the highest sensitivity of the pack and according to that, they are an easy load for low power tube amplifiers. On test they didn't cause any problem to the Prologue One. With all the songs selected we observed good dynamics, with good reproduction of highs and mids, nice voices but with a restricted bass extension. With Stacey Kent's "Shall we dance" the bass lines showed some tendency to sound too low. We know that we're talking about bookself speakers with limited enclosure volume and so this is not something strange. With Norah Jones' songs the voice was again very nice, but the same sensation appeared again with low frequencies. Some percussion in Cassandra Wilson's songs were less present than usual and Nnenna Freelon's tracks lacked some double bass definition. The Profile 908 are good speakers, perhaps for listeners that need a more relaxed sound. If you consider buying them, try to ask for an audition to be sure that they are what you're looking for.

Epos M5

The Epos M5 are 2 way, rear bass reflex speakers. Their sensitivity is 88db/1w/1m, the impedance is 4 ohm, the recommeded amplifier power range is from 25 watts to 100 watts and the frequency response is 60 Hz-20 kHz. Their price is 600 €. The finish is very good and very elegant. The red colour of the finish gives the speakers a very nice look. The speakers use heavy metal front grilles that must be removed for listening.

With the Amphion Ion, these are the smallest speakers of the pack. They have a 4 ohm impedance and this is an easy load for amps like the one used. The tone of the speakers was very nice, the sound I like and I'm used to (is this the english sound?). The first impression was that the speakers were perhaps too small and the they're best suited for small listening rooms. The tone, as I said before, was very good, very clean, but the high and low extremes were limited. If we turned up the volume above the fixed limit, we got more presence but the enclosure size was what it was. The best thing of these speakers was their general tone, the tone I would look for in bigger speakers. The voices were clear, the bass clean but limited, but I believe that in a small room they can do an excellent job. With Gloria Estefan "Por un beso" the wind section asked for a bigger enclosure, but all sounded very clear. The same happened with Nnenna Freelon. After listening them more time I was feeling very comfortable with their sound. Madeleine Peyroux version of Joni Mitchell's "River" sounded very nice and the voice of Diana Krall from the songs of her last record, was cleer. The M5 showed very good virtues, a nice tone. They they lack some punch but in small rooms they can sound really good. And if we consider their price we could see that we're in front of a pair of speakers that must be seriously considered.

ProAc Response 1 SC

The ProAc Response 1 SC are 2 way, rear bass reflex speakers. Their sensitivity is 86db/1w/1m, the impedance is 8 ohm, the recommended amplifier power range is from 25 watts to 100 watts and the frequency response is 38 Hz-30 kHz. Their price is about 2100 €. Their finish is excellent. The bass drives uses a transparent cone.

These are the only speakers that were selected in advance. I listened to them paired with an Audio Research VSi55 integrated tube amplifier and they sounded great. So I wanted to use them in this audition with the Prima Luna, even their price. Although they have the lowest sensitivity and their impedance is 8 ohm, the 1 SC are happy with tube amps. The very first impressions were about the treble. They had the best treble of all the speakers, with an extension above all other units. The tone was also very good, with the second best bass of all the rounders (after the Tablette 2000). Giving the size of the units (remember, they are monitors) the bass is one of its best points. As we said before with the VSi55 the speakers sounded great and I believe that they are a great match for this kind of amps, perhaps in a higher range than the Prologue One. Nnenna Freelon's songs sounded wonderful, with the extra treble extension, clear bass and a very nice piano. In general terms, the 1 SC revealed themselves as the best performers, although if we are picky, the bass of the Tablette had more extension.

ProAc Tablette 2000

The ProAc Tablette 2000 are 2 way, rear bass reflex speakers. Their sensitivity is 87db/1w/1m, the impedance is 8 ohm, the recommended amplifier power range is from 20 watts to 150 watts and the frequency response is 35 Hz-30 kHz. Their price is about 2000 €. Their finish is excellent. This model has been replaced by the Tablette Reference 8 and Reference 8 Signature that has a smaller enclosure, the same as the first Tablette.

We decided to listen to the Tablette 2000 while listening to the 1 SC, to see if we could improve in some way the sound we got from these speakers. As we have said, the bass extension of the Tablette is better than the 1 SC. As them, they are happy with tube amplifiers. If we want extra bass, this could be our speakers, although the general tone of the 1 SC is better. With all the song we listened to, the extra bass extension was clearly heard, maybe due to the bigger bass driver and a better low frequency response. As with almost all the speakers of the pack, the voices were very good. With all these attributes we thought considering them the best speakers of the group, but they got the second place after the 1 SC.

Epos M15

The Epos M15 are 2 way, rear bass reflex speakers. Their sensitivity is 87db/1w/1m, the impedance is 8 ohm, the maximum power handling is 100 watts and the frequency response is 48 Hz-20 kHz. Their price is about 1200 €. Their finish is excellent. This is the only floostander speaker of the pack.

We tested the Epos M15 to see what they could do with the Prima Luna after the good sensations we got when we listened to the Epos M5. The extra volume of the M15 enclosure and their better low frequency response was rapidly seen, although the bass is better on the Response 1SC and the Tablette 2000, that are smaller. The tone was very similar to the M5 and Norah Jones "Seven Years" sounded very nice, a sound I'm used to listen at home and that I like very much. Being floorstanders, we should know that they need more space and in the right room they can give pleasing listening sessions.

Amphion Ion

The Amphion Ion are 2 way, rear bass reflex speakers. Their sensitivity is 86db/1w/1m, the impedance is 8 ohm, the recommended amplifier power range is from 20 watts to 100 watts and the frequency response is 55 Hz-20 kHz. Their price is about 800 €. Their finish is completely different to the other speakers, because the box in painted in matt black. The tweeter is mounted in a quasi-horn that Amphion calls wave-guide.

The Amphion were selected for the test because the people at Pont Reyed recommended them. And what a revelation! The Ion are the smaller speakers of the group but as sometimes happens... the size doesn't matters. First, they have the second best treble extension of the group, maybe due to the quasi-horn tweeter and the bass is suprising considering their size. The tone is similar to the english speakers of the group, clean, defined and with nice bass. The people at Pont Reyes told me that their biggest brothers, the Argon 2, sound even better, and after listening their explanation I asked for a future audition. According to their specs, these are the worst suited speakers to use with low power tube amplifiers, and so I would recommend extra listening sessions to potential buyers with higher power amplifiers.

With the comments about the Ion, we end this article, our modest contribution to the tube amplifier and speaker combination question. As you can imagine, these aren't all the speakers available to combine with tube amplifiers, but we believe that the objective of the article, to show some alternatives, is achieved. As we said before the last word is yours, now you have to listen and to test the speakers that best suits your needs. Maybe it will be other than the speakers showed in this article, but, you know, there're so many good speakers to listen to out there!