Rleff, if you have a set of ZEROs a set of M-60s will do OK. The big problem is the highs- M-60s don't drive 2-3 ohms all that well and that's where the ZEROs help out.
Amp advice for Sound Lab M-2's
Looking for opinions for a amp to use with my Sound Lab M-2 speakers. I am down to considering the Bryston 7b – SST, Parasound JC – 1, and the new Sanders Sound ESL amp. The former owner of the M-2’s used a Pass X-350, but I found that it sounded dry, and very thin. No warmth at all. Lots of older Krells out there, great bottom ends, but again often very cool sounding. I’m not that familiar with the Levinson’s, another option, maybe. The Sound Labs do need a good honest 300 watts > 8 ohms, and 600 watts > 4 ohms. Most amps don’t have the combination of voltage and current ratings to handle the speakers. I am leaning towards the Brystons. Overall they seem to be an amp that is easy to live with, while maybe not the best over all, they do a lot right. Ideas and experiences appreciated. By the way, the listening room is 23x21, with a ceiling that is 9 feet on one long wall, and slopes up to 16 feet on the other long wall. 15 feet of the highest long wall is open right in the middle of the wall. So the room can really suck up speaker output. Thanks.
Showing 3 responses by atmasphere
Hi Chris, the answer has to do with the 'voltage source' quality of most transistor amps. What we are talking about is the fact that regardless of load, a transistor amp will (attempt, at least, to) put out the same voltage. For example, in the case of an 8 ohm load, a 100 watt transistor amp will put out about 28 volts. Into 4 ohms, it makes that same voltage- that's 200 watts. What happens with higher impedance loads? It makes the same voltage- 16 ohms and 28 volts is 50 watts; into 32 ohms that would be only about 25 watts. Most transistor amp employ a fair amount of feedback, which helps to 'linearize' the voltage response (according to the rules of the Voltage Paradigm); this helps flatten the frequency response of the amp a little but also means a 100 watt amp is not going to be making much power on the Sound Labs, and is why the speaker gets paired with what appear otherwise to be some very high powered transistor amps, to get around this phenomena. But regardless of the power, it will never be 100% successful if the amplifier cannot satisfy the rules that the speaker operates by. IOW, the rules of the Voltage Paradigm don't help you all that much when faced by the load of a typical ESL. If you had an amplifier that made constant **power** into all loads, then you would get much flatter response out of the speaker (most people have **no idea** how well they play bass, for example). Amps that can do that on the Sound Lab are very few and far between. This is part of the reason that the speaker has such a varied reaction amongst audiophiles: no doubt most people have not heard what the speaker can really do when driven right. |
Gammastrep, your speakers are fundamentally different from box speakers as you know. The impedance curve is the result of 2 factors, neither of which has anything to do with resonance. The result is that the 'conventional wisdom' about using a transistor amp to make the speaker sing is wildly inaccurate. first, read http://www.atma-sphere.com/papers/paradigm_paper2.html Your speakers are a Power Paradigm technology, so voltage-source power amps like big transistor amps are all going to have similar issues- too bright in the highs and not nearly enough bass. If you think about it, lets try the example of a 600 watt transistor amp. Into the bass, which is over 30 ohms in some areas, that amp will only make about 150 watts. IOW, any 200-watt tube amp will be able to keep up with it, as a tube amplifier will be able to deliver substantial power into an impedance like that. Any time you mix Voltage and Power paradigm technologies, you will get a tonal anomaly, in this case too much highs and not enough bass. The bottom line is that you need to seek a tube amplifier if you wish to get the most out of this speaker. As you have noted, that tube amp should be capable of some power. IME you will need about 200 watts per channel to get things happening. |