120V Rail 24-Ch. Summing and Monitoring Console

Fundamental research

Shortly after the turn of the millennium, SPL laid down new foundations for the improvement of analog audio signal processing. Thanks to new components, circuitries and manufacturing methods, we were able to increase the operating voltage enormously.

Up to then, average operating voltage ranged form 30 to 36 volts (+/- 15 or 18 volts, considering that voltage supply is symmetrical). Maximum operating voltages reached 60 volts  (+/- 30 volts). At the core of our new technology are the handmade OP-amps that operate at 120 volts (+/- 60 volts), which means that we have in fact doubled the highest levels ever reached until then.


Next-Generation Analog

The first products to integrate the 120-volt technology were exclusive, handmade custom solutions for major mastering studios. At the time, music production had already been uprooted by digital technology and the changes it brought with itself in terms of outfitting and workflow in music studios. Coincidentally, a new „mastering“ sector had already been established — both in terms of the actual process and the gear in studios. If traditional recording and mixing studios were on their way to digitalization, the most sophisticated mastering studios were and have always been keen on analog technology, including high-quality signal processors that can still make a difference compared to the widely available software solutions. But also technically demanding requirements such as superior sounding and designed switching and monitoring consoles were among the products we were able to offer. While analog technology was being heralded as dead, SPL was decisively going in the opposite direction: we were able to deliver analog products of the highest quality whose performance surpassed all previous specifications — regardless of whether it was in the analog or digital realm.


Why is a high operating voltage so important?

If we consider that the basis of every circuit is directly related to a voltage/performance ratio, the operating voltage is crucial for the performance of any circuit. Given that audio technology is conceived to translate sound into voltage, doubling the formerly highest operating voltage available results in a great improvement, specially with regard to signal dynamics and the way they are processed. Technically speaking, a wider dynamic range also means that the gap between the actual signal and other undesired signals, such as noise and distortion, is larger — in the case of the Neos console, for example, this results in not hearing any noises at all, regardless of the situation.


Highest performance for ultimate sound quality

Our measurements reveal the improvements the 120-volt technology offers in comparison to standard solutions. All these advantages are due to the oversized signal traces, the rigorous selection of every single element and, of course, the handmade components that contain no unnecessary audio processing parts (which are very common in mass-produced operation amplifiers). But the technical specifications and design say very little about the actual sound of an audio equipment. At the end of the day, an audio device has to prove itself in use in the hands of sound engineers and musicians. We can state with great satisfaction that our solution not only prevailed — ever since their introduction, our 120-volt products have passed all tests and proven worthy of the best. Now the Neos console represents a solution that transfers unsurpassed performance into ultimate sound quality.


Integration and wiring examples

With a 24-channel interface and DB 25 connectors in TASCAM standard, wiring is almost too easy: connection is given and channel assignment follows the DAW setup.
The following examples cover a bit more complex scenarios that may yield some inspiration for individual solutions.


Three eight-channel converters

A common way to feed the 24 channels of the Neos would be to use three eight-channel D/A converters. As a rule, one converter is defined as the main converter and the two others are connected in chain. As long as the converters have the same DB25 connectors the connection is straight forward and the channel assignment corresponds to the one in the DAW’s setup.

A high-quality two-channel converter might the best option to record the signal of the Neos’ Rec. Out. The A/D stage could also be integrated through the S/PDIF inputs of the main converter. The recorded signal can be routed to the two-channel converter through the S/PDIF outputs of the main converter, whose D/A output would then be connected to the Tape Return of the Neos.


Converters with separate outputs

If the analog outputs of the converter are available as separate XLR and jack connectors, a clever channel assignment could save converter channels. Typical sessions have usually four mono channels (vocals, snare, kick, and bass) while the rest of the elements are available as stereo stems in the DAW (keyboards, guitars, backing vocals, overheads, toms, etc.). In this scenario you can make the final mixdown with the Neos. Nevertheless, do take into consideration that the more channels available for a production, the better.

Here is an example of such a session: once again we have three eight-channel converters, however this time they have separate outputs connected via eight XLR/jack-to-D25 snake cables. In the DAW, route the four mono channels to outputs 5, 6, 7, and 8 of the first converter. Afterwards, connect the converter outputs with the Neos DB25 inputs 1, 3, 5, and 7. That way, the mono signals are now controlled by the first faders of the Neos — and considering that the input paths are stereo, whenever you use mono signals one of the channels is free (in this example, DB25 outputs 2, 4, 6, and 8). All other stereo stems from the DAW should be routed to the Neos through the two other converters. On the first converter you still have four output channels left, which you can use for the Tape Return input of the Neos and a headphones mix.