Divide and conquer

Power Conditioner Audes DT-3600

Audes
That‘s right, there was something. Namely a visit to Jõhvi in Estonia this summer, the photo documentation of which you as a regular reader will surely remember. You can‘t? Then you are welcome to take a look at the story online at lp-magazin.de with even more pictures.  

By then at the latest, you will be fully aware that we are dealing with a manufacturer with a high level of vertical integration, for whom mains filters in various forms have now developed into an important branch of business.  

Power Conditioning
What all models have in common is the fact that an isolating transformer serves as the central functional component. While conventional transformers change the voltage between the input and output sides (in this case the primary and secondary sides), the isolating transformer keeps it constant - at least in the long term. Due to its magnetic properties (the inductance), the transformer attempts to counteract short-term voltage changes on the primary side and keep the secondary voltage as constant as possible. This is a low-pass filter effect, which is very desirable here: unwanted high-frequency voltage components (mains interference) simply do not get through. The energy storage effect of the transformer also ensures a certain stabilization of the output voltage during load changes - we are also happy to accept this fact.  

The greater the inductance of the transformer, the greater the filter and storage effect. Audes recognized this early on and has since been working intensively on the development of fairly large-calibre isolating transformers. The Estonians produce monsters with a load capacity of up to five kilovolt amperes - or 5000 watts, which sounds better, but is not quite technically correct.  

Recently, they have started to offer devices with several isolating transformers. The crowning glory of these is the DT-3600 power conditioner, which is the subject of this article. The device, which can handle a total of 3600 VA, weighs a heavy 61 kilograms and costs an impressive 10,000 euros.  

In return, you get an extremely impressive monument in plain black or white, which you should think carefully about housing and transporting beforehand, as this is quite a challenge.   

Two circles
The filter effect of the DT-3600 is spread over two circuits.

Eight of the twelve rear sockets are connected to the output of a massive 3300 VA toroidal transformer. This is where power-hungry consumers such as integrated and power amplifi ers are connected. A second, much smaller transformer serves the four „Group 2“ sockets, which are intended for small consumers such as source devices. This division is not set in stone; it would also be possible, for example, to connect only (small) consumers powered by a switching power supply to the small circuit and reserve the higherload part exclusively for conventionally powered consumers. The purpose of this division is precisely to create as thorough a separation as possible between the two sections so that interference cannot couple back and forth between the two worlds. Analog components on one side, digital devices on the other? You can try that too.  

DC blocker
But that‘s not all. The DC-3600 also has a switchable DC voltage filter that removes any DC components from the input voltage. This reduces any mechanical humming noises that may occur in the loads and the filter transformers themselves, and it also sounds better. Audes also builds something like this as an external ballast, which we have already tested.  

Appearances
In contrast to the early Audes mains conditioners, there are now beautiful analog pointer instruments. The DT-3600 has three of them. One shows the mains voltage, one the current flowing from the large transformer and one the current flowing from the small one. The latter in particular makes sense, because with a maximum current of 1.5 amperes, you want to keep an eye on consumption. Three pleasantly discreet LEDs signal the presence of mains voltage, the operational readiness of the BC blocker and the activity of the separately switchable „Group 2“. On the back there are the corresponding switches and one that switches the back lighting. On the input side, there is a 20 ampere IEC socket and a reliable connection cable is included. The twelve sockets are made in Germany and are of good quality. This can also be said about the housing, which is made of a highly damping and heavy composite material, not entirely dissimilar to the well-known material Corian.  

Listening test
As always when using Audes‘ potent power conditioners, the switch from a standard mains supply is nothing short of a shock. So much more space, a much improved dynamic response, more fervor and expression in vocals - it‘s hard to believe how much we cut down our music reproduction these days without the use of such a tool. We did our experiments with an integrated amplifier, a phono preamp and a turntable and found out a few interesting things. Firstly, the record player clearly wants to be in „Group 2“. Nina Simone clearly sounds more confident and expressive when the turntable is decoupled from the main consumers. This is especially true for the Transrotor Alto TMD, which is powered by a switching power supply. The phono preamplifier - in this case the Unison tube from this magazine - was allowed to remain in Group 1 and got along splendidly with the Exposure integrated amplifier. Of course, I also connected my notebook power supply for fun. When it‘s plugged into group 2 with the turntable, its influence is almost inaudible; in group 1 together with the integrated amplifi er and phono preamp, it sounds noticeably grayer and duller. This means that the isolation effect of the two transformers is clearly audible and welcome.

Very convinced by this result, we have decided to permanently entrust the DT-3600 with powering the system in our listening room. The sonic gain from the device is so convincing that there is hardly any alternative.