corona impact on production and sales


New digital audio interface and protocol

Backwards compatible with Toslink interface and S/PDIF protocol. Our new electro-optical digital audio interface and low jitter protocol eliminates -unwanted- jitter in digital audio source, digital audio interlink, and all DAC circuits even when significant crosstalk is present. It has to be generated directly by software (UPL96ETL and U192ETL).


USB transport with ElectroTos/Toslink interface and low jitter ElectroTos protocol

Backwards compatible with Toslink interface and S/PDIF protocol. Supports asynchronous USB audio Class 2, 44.1/16 to 192/24. Based on XMOS XU208. Low jitter system and audio clocks, 24MHz, 22.5792MHz, 24.576MHz. Each oscillator has separate RF supply noise filtering. Advanced synchroniser / driver circuit for XMOS jitter attenuation. USB bus powered (5V).


Very clean USB memory stick -reference- transport with ElectroTos/Toslink interface and ElectroTos low jitter protocol.

Backwards compatible with Toslink interface and S/PDIF protocol. PC app for controlling the UPL96ETL over USB. Supports WAV files using ID3v2.3.0 metadata with jpeg/png cover-art. User interface with CD display on USB memory stick and lookup/seach in all CDs on all USB memory sticks that have metadata imported previously. Supports 44.1/16 to 96/24. Based on STM32 ARM. Low jitter system and audio clocks, 24MHz, 22.5792MHz, 45.1584MHz, 24.576MHz, 49.152MHz. Each oscillator has separate RF supply noise filtering. Advanced synchroniser / driver circuit for jitter attenuation. USB bus powered (5V).


Discrete, ultra low noise multi-pattern fractal DAC with ElectroTos input.

The DA96ETF pairs with U192ETL or UPL96ETL, these support the ElectroTos low jitter protocol. Note: the DA96ETF does not support standard Toslink protocol, it will only produce noise when attempting to drive it with standard Toslink sources. Sample rate support: 44.1, 48, 88.2, and 96 KHz. Bit depth: automatic (ElectroTos protocol). Standard digital audio protocols are no longer used / generated anywhere in the DA96ETF. D/A converter type: Fractal multi-pattern converter, 32 bit core / channel (this type of converter is -completely- different from all existing audio D/A converters). Fractal multi-pattern converters offer extreme long term accuracy (with given component tolerances), low output impedance (375 Ohms), and extremely low digital interface switching noise because of the parallel data interface (highest switching frequency equals the sample rate / ELE latch signal). System: unfiltered NOS (fully passive output circuit). By using 88.2 or 96 KHz, 2 x oversampling can be obtained. Included power supply: external, 5V/100mA (4.8 ... 5V5), connection USB-B (large).

Also see: Resolution and clarity


Passive stepped volume attenuator.

Manual operated 24 step volume attenuator for our DA96ETF.


Passive stepped universal volume attenuator.

Manual operated 24 step universal volume attenuator for existing DACs.


High resolution headphone amplifier using a large bandwidth servo system to drive the headphone speakers.

The high resolution headphone amplifier uses a servo system that produces no cross-over distortion at all and consumes constant power (power ratio method). The speaker distortion basically vanishes and offers the most realistic detailed high resolution music reproduction.


Active open baffle speaker based on a servo amplifier.

The OBS100 is an active open baffle speaker that is based on a servo amplifier, similar to the one used in the SHPB10. The OBS100 senses and corrects speaker membrane movement. The ac voltage generated by the voice coil is used as feedback signal for the servo. The result is much lower overall distortion, higher resolution and compensation for voice coil temperature changes and related distortion. The servo amplifier soft clips similar to a tube amplifier. The audio spectrum is mainly reproduced by one 8" full range speaker that acts as point source, this helps to get clean coherent music reproduction. Two large 15" bass speakers only support the lowest frequencies below 100Hz. The servo ensures that bass reproduction is unexpectedly good for an open baffle speaker. The OBS100 offers realistic music reproduction and high resolution.


Howto connect our audio components to each other, and howto connect them to existing audio components.

Our audio components are designed to perfectly complement each other. Using one of our transports in combination with our DAC, volume attenuator and headphone amplifier or our active open baffle speaker will produce music instead of sound. With this combination you can exactly hear what we hear and enjoy music like never before, just like we have for the last couple of months.
Apart from buying a whole set you could also start with improving your current setup. Our two transports can be used with any DAC equipped with a Toslink input, the UPL96ETL and the U192ETL will introduce you to ElectroTos technology and could already improve sound quality significantly. Also our SVC24U stepped volume attenuator and our SHPB10 headphone amplifier / OBS100 active open baffle speaker could also be a big improvement in sound quality with existing audio components. Check out the connection diagram below to see how to connect our audio components to each other, or howto connect them to existing audio components.

When connecting our U192ETL or UPL96ETL transports to an existing Toslink DAC make sure to disconnect all other inputs from the DAC !

Resolution and clarity

The sound quality of an audio set depends on the cumulative distortion introduced in the entire audio signal path.

It is best to avoid audio components that are not strictly required like pre amplifiers and coupling caps for example. It would be best to connect the DA96ETF directly to the power amplifier input, and use a shunt volume control like our SVC24 to control the volume. In order to get an impression of what the DA96ETF is really capable of one can directly connect high Ohmic studio headphones like the Beyerdynamic DT 990 pro to the DA96ETF outputs, if these play too loud one can add a shunt resistor of 33 ... 100 Ohms or use our SVC24 shunt volume control. This can serve as reference when attempting to get similar resolution and transparency out of the speakers. Similar applies to analogue sources like vinyl and tape, so this is by no means a DAC only problem!

The amplifier - speaker combination causes most degrading as related distortion is always very high (typically 2 ... 20%). This is mainly caused by the steering method (constant voltage steering). This steering method is not optimal to drive a speaker voice coil where the magnetic field depends on the Ampère windings. The result is both, resolution and transparency loss.

Tube amplifiers are more compatible with most speakers as tube amplifiers are usually based on quasi constant current steering, this will increase resolution and clarity compared to semiconductor amplifiers that are based on constant voltage steering. This may be one of the reasons why tube amplifiers are still popular.

If a semiconductor amplifier fails to offer similar resolution and clarity compared to the DT990 studio headphones reference, there is an easy trick to improve this. It is not the perfect solution but it can help to come closer to the studio headphones reference.

Connect a 4.7 Ohms power series resistor between the semiconductor amplifier output and an 8 Ohms speaker, or a 2.2 Ohm power series resistor for a 4 Ohm speaker. This will shift steering from constant voltage to quasi constant current steering. The optimal series resistor value equals approx. speaker impedance divided by 1.6. Use power resistors with a rating of amplifier output power divided by 2.6, so for a 40W rms output amplifier use 15W series resistor.

Our SHPB10 headphones buffer and OBS100 active open baffle speakers are based on novel servo amplifiers that ensure that the speaker membrane accurately tracks the signal. This way we have almost no loss of resolution and clarity in the amplifier - speaker combination.