GOLDMUND - Swiss Made High-End Audio Equipment

The study of the new Goldmund “Universal Preamplifier” concept started in 1999. Facing the huge sonic difference between highest quality D/A converters and Analogue preamplifiers compared to very poor sounding Multi-channel processors, Goldmund decided to unify the 2 domains in a single machine which would provide even better sound than Analogue preamplifier and extreme quality for the Multi-channel domain.

The Research started with the following goals :

• The sonic result of a “Universal Preamplifier” used in a 2-channel system should be better than the sound quality of a Goldmund Mimesis 22 Analogue Preamplifier, considered as the best available analogue reference.
• The “Universal Preamplifier” should considerably improve the sonic quality of Multi-channel encoded sources to establish a new standard level of performance, unknown before but appropriate for Goldmund Customers.
• The “Universal Preamplifier” should be as easy to use as an Analogue Preamplifier. A simple input switching between a 2-channel and multi-channel source should automatically activate all needed circuits accordingly without the user even noticing it.
• The “Universal Preamplifier” should accept digital and analogue inputs including multi-channel analogue.
• The “Universal Preamplifier” would need no equipment change for a customer migrating from 2-channel to multi-channel.
• The “Universal Preamplifier” should impose no constraint in speaker number or speaker placement in order to improve the surround quality and help the installation in critical decorations.
• The “Universal Preamplifier” should accept all existing multi-channel formats and integrate new emerging formats by a simple software download.

• The Direct PCM Path

  The Goldmund Format Detector circuit takes each input and inspects in real time its format before running it either to the multi-channel decoder or directly into a PCM direct path. This improves greatly the reproduction of 2�channel sound avoiding the path through the decoder with its severe signal restrictions and anyhow adopted by all other multi-channel processors.

• The Digital Signal Integrity circuitry

  In order to keep the initial signal quality, all digital signals run and processed in the “Universal Preamplifier” are first up-sampled to 96kHz 24 bits to avoid the unavoidable losses in further processing, including matrixing and volume control. It allows to really run the DSPs in full float precision with zero-error.

• The Parallel Input Processing

  All analogue and digital inputs are run in parallel to the matrixing circuit to allow a maximum of separate zones running different sources. Despite its extreme cost, it makes the “Universal Preamplifier” able to run a maximum of external zones and to act as a real Analogue multi-channel preamplifier

• The full Inputs and Outputs Matrixing

  All input signals as well as the 8 output channels issued from the Goldmund Decoder are parallel fed to a DSP Bank where they may be mixed, adjusted in level, in phase, in delay to build more output speakers different signals over the number of usual multi-channel format

• The Stellavox A/D circuitry.

  Ultra-high quality A/D circuitry is used to enter the analogue inputs into the system. One of the professional A/D circuit used by Stellavox for its laboratory-grade reference A/D machines is used for each analogue input channel.

• The Full-Digital approach

  In a typical 2-channel or multi-channel system, the analogue circuitry and cables are the major source of signal quality loss. Adopting a system’s topology where the D/A are pushed from before the preamplifier to before the power amplifier and close to it, is suppressing most of these losses. The “Universal Preamplifier” will have only digital outputs so the longer cables (up to the power amplifiers) are run in digital with no loss, even in large rooms Home-Theater installations.

• The Goldmund Decoder DSP Software.

  A seriously improved multi-channel decoding quality is achieved by using a specially-developed Goldmund decoder software, a higher standard multi-channel DSP decoding algorithm using the AudioNetworks DASE technology to rebuild signal quality after decompression.

After 3 years of technological research and concept creation, a typical strategic approach from the company, the Goldmund Development Team started the final development in January 2002. The team used 4 engineers :

• Sebastien Benz (Alize4 - Alize5) : Hardware digital.
• Raphael Pasche : Hardware digital and DSP software.
• Antoine Petroff (Job4 - Job5) : Hardware analogue and power supply.
• Alain Capt : Microprocessor software.

Despite the extreme circuit complexity and the level of software required, only 52 month/man were spent for the 3 units.

During the development of the Goldmund “Universal Preamplifier” the development team encountered new major challenges :

Hardware Challenge

• Multiple clock noise avoidance for signal integrity

  On a very complex board that includes digital audio signal at various frequencies (44.1 kHz, 48 kHz, 96 kHz), Ultra-fast DSP clock, CPLD clocks and 2 x separate Microprocessor clocks, all these signal interfere and usually create noise and imprecisely timed signals which may be ruining the quality of the sound. In such environment, only an ultra-professional approach of the PCB design can make the whole system perfect.

  Using a fully automated ultra-dense SMD technology is mandatory and the 4-layers layout challenge is even higher. This is by far the most difficult design in such a high-technology unit and it took the team the highest effort to achieve the unique performance of the main board, now the same in the 3 Goldmund “Universal Preamplifiers”.

Software Challenges

• Extreme DSP software compacity and time-efficiency

  To minimize hardware cost and keep the extreme precision signals in the DSP operations need a very optimized DSP code where any single instruction counts. Having 44 x input signals and 32 x output signals at 96kHz 24dB to process simultaneously with the maximum precision and in real time has proved to be a software nightmare.

• Very fast microprocessor software for invisible automation

  When a user press one input button on the remote, the 2 microprocessors inside the unit have to process with literally zero-delay an extremely complete set of :

  • various tests on the signal to detect its format unequivocally
  • reload the decoder DSP with the software for the found format
  • load the Matrixing DSP bank with the appropriate levels, mix and delays for the 32 outputs usable for this format.
  • Take all precaution so the other playing sources, zones etc remain unaltered.