Smart Sound P1000B & P2000

Do you want to hear how good your audio equipment can really sound? Martin Walker investigates a product that may significantly improve the sound of your studio.

A contaminated mains power supply can be the cause of a great deal of studio malaise. It's all too easy to assume that one simply gets a 50Hz sinewave coming out of the wall at 240 volts RMS (in the UK), and we only really notice if it disappears altogether. However, a lot of electrical grunge can be introduced into the mains by nearby industrial premises, old or poor‑quality wiring, RF interference, thermostats clicking, fridges buzzing... the list goes on and on.

Short‑duration, high‑voltage spikes can cause havoc with computer equipment, but it's possible to remove these by fitting transient suppressors at the source of the problem. However, basic distortion of the mains sinewave isn't as easy to remedy. Mains power waveforms may include several percent total harmonic distortion and while well‑designed mains power supplies in our studio equipment can normally remove the effects of differential distortion (between live and neutral) when they convert the AC supply into DC voltages for the internal circuitry, what they can't do is deal with common‑mode distortion (where the same interference is present on both wires) — for this you require a substantially engineered mains isolation transformer.

Enter the Smart Sound P1000B and P2000 Power Conditioners. These are essentially large toroidally‑wound 1:1 transformers, which are designed to operate extremely quietly so that they can be used within studios. I was supplied with the larger of the two models, the P1000B (205 x 205 x 305mm), which can handle a maximum continuous current of 4.5A with peaks of 9A — the smaller P2000 (102 x 205 x 305mm), though otherwise functionally identical, has only half its sibling's current handling. Both units incorporate a thermal safety cutout switch which operates at 98°C.

The P1000B occupies a utilitarian metal case and is extremely heavy, weighing in at 28kg. Installation is simplicity itself — just unplug your existing audio gear, plug the conditioner into a convenient wall socket and then connect your audio gear to the double‑switched mains socket at the far end of the conditioner box.

I first tried the P1000B with a run‑of‑the‑mill (£600) hi‑fi system, and the difference was remarkable. No subtle changes here — from the moment I powered the system up it sounded like one twice the price. The most obvious change was that everything seemed to come into focus — I could hear details that were previously inaudible, and the stereo imaging was considerably improved. The bass end was also considerably deeper and more powerful, and the top end had greater clarity and resolution. Frankly I was amazed at the difference!

I then carried the box into my small studio, and plumbed in as much of my gear as I could manage. The differences were still there, but perhaps not so marked — perhaps more expensive units have better‑engineered power supplies. Despite this, there were still distinct sonic improvements, particularly where digital circuitry such as CD players and soundcards were concerned.

The only downside is the price: this is a heavy, extremely well‑engineered specialist transformer, and therefore very costly to manufacture. The kilowatt (1000VA) version I tried retails at £399, but you should be able to run the majority of your audio gear from this (add up the VA ratings printed on the back of each case to make sure). The smaller P2000 500VA version is also available at £299. Since the most significant improvements seem to be with digital equipment, you could leave your power amps on a separate circuit and use the smaller conditioner on the remainder of your lower rated gear. Sadly, an even cheaper 250VA version designed primarily for digital audio equipment had to be removed from the range because so many people ignored the power rating, used it with power amps, and burnt out the windings (despite an internal thermal fuse that normally resets automatically).

Using the P1000B was a sobering experience. After hearing what my gear is capable of when the pollution of the mains supply is removed, I'm not looking forward to removing this product from my studio and becoming infected again. Professional studios would be well advised to investigate this range of products as soon as possible. Rack mounting versions are also expected shortly, and special versions are also available for step‑up and step‑down use with 120V equipment or supplies.