We've tested and found several amplifiers that perform especially well with JansZen loudspeakers, and comport nicely with our tenet that transparency is essential to reliving the recorded performance, yet these still allow for variations in taste.
Bear in mind that the sensitivity of the Carmelitas is about 84 dB/1W/1m and of the Valentinas is about 87 dB/1W/1m (based on pink noise, which best represents real world sensitivity). This means the Valentina will give a maximum SPL of about 103 dB from 40W, about 105 dB from 60W, and about 107 from 100W. Beyond that, the speakers can reproduce brief transients, such as drum whacks and string plucks, up to about an additional 3 dB, but not steady state. This bit of extra headroom for transients makes music sound more realistic when the average playback level is high. Subtract 3 dB from the maximum SPL figures stated above for the Carmelitas.
Solid State: The clearest sounding solid state amplifier we've tested to date is the Benchmark AHB2. This is a unique, 2-channel amplifier priced at $3,000 and sold direct on a 30 day trial. Its 100W/ch/8Ω power (190W/ch/4Ω) provides sufficient headroom for moderate playback levels. For maximum reproduction of transients while the playback level is already high, a pair of them set into monoblock mode (bridged) will more than do the job.
Hybrid: The best tube/solid state hybrid amplifier we've tested to date is the 400R from Audio by Van Alstine. This is a wonderful sounding, 2-channel amplifier that puts out about 225W/ch/8Ω. It's sold direct at $2,900 on a 30 day trial. This amplifier has been popular with JansZen owners who want the best of tube sound without any compromises. It also can drive the speakers to their absolute maximum SPL on transients.This is the amplifier we use at the factory for demonstrations as well as for our own listening pleasure.
Its triode input stage is run lightly, so the tubes are bound to last for decades. That stage is followed by a bank of special power MOSFETs for driving the output, with a minimum of circuitry in between. (MOSFETs are type of transistor, but like tubes, they function as voltage controlled current sources, with silicon taking the place of a vacuum, so the sound is less transistor-like than from more commonly used bipolar transistors.) Every DC supply within the amplifier is individually regulated, providing exceptionally high immunity to mains power fluctuations as well as a high degree of indifference to load demand.
Tube, with transformer output: The traditional tube amp we like best, and which several JansZen owners report as giving incomparably good results in their systems, is the Decware Zen Mystery Amp (ZMA) at $5,700. It was designed by Steve Deckert with his usual goal of simplifying the circuitry as much as possible, for the purpose of providing the greatest transparency. This transparency is just as with his low power amplifiers, despite delivering 60W/ch (KT88) or 40W/ch (EL34) output.power. Practically infinite tube rolling opportunities are provided by the wide tube compatibility (6N1P / 6922 / 6DJ8 / 7DJ8 as well as KT77, EL34, 7027, 5881, and 6L6). Some will find 60W or 40W is not enough power, but JansZen owners' experiences say that anyone who plays music at moderate levels will be quite satisfied.
Tube, transformerless: A very interesting and great sounding 2-channel tube amplifier is the ZOTL from Linear Tube Audio (LTA) at $6800. As with the Decware amplifier, several JansZen owners report exceptional results with this amplifier in their systems, especially when paired with the microZOTL preamplifier at $4400.
The first surprise is that it's as light as a solid state amplifier, and then that its frequency response is flat to extremely low frequencies. Both characteristics are thanks to the lack of heavy output transformers. This isn't accomplished with a big bank of tubes running in parallel, but by down-converting the tube impedance to speaker level using advanced circuitry. You might recognize this as a David Berning design, which it is, but at a far lower price than his usual. The power output is 40W/ch, which some will find inadequate, but again, JansZen owners' experiences say that you'll be quite satisfied, as long as you aren't expecting to see your belly shake.
So far, we've found only one company whose DACs can take a standard CD and make it sound like it's analog without the drawbacks. In addition, their DACs can handle up to DSD256 natively and PCM up to 24/384, and do so with exceptional aplomb. That company is exaSound. Their 2-channel DAC is the e32 Mark II, which we use here at the factory for demos and our own enjoyment. They also make an 8-channel DAC, a streamer, a combination streamer/DAC, and two music servers.
These are USB DACs, but also have S/PDIF inputs (both wired and optical). There are both RCA and balanced XLR outputs. Extreme USB de-jittering and power supply filtering contribute to their silky smoothness. Their way of handling the volume control conserves the entire bit depth and leaves the S/N ratio at the limits of measurability. The latest professional Sabre DAC ICs are employed, and the surrounding circuitry squeezes every bit of potential from these remarkable chips.
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