Ghielmetti Digital or Analogue Patch Panels
Ghielmetti patches all; These are patching systems all suitable for AES/EBU digital audio, RS232 and other data applications, as well as analogue audio. Please contact our sales team for further information and advice on all items in the extensive Ghielmetti range.
The basis of the system is a series of pairs of gold plated contact wafers, which run vertically within each panel (three pairs of wafers per channel per layer - A, B and ground). There are two layers of contacts in each panel, without connection between the layers. Circuit routing is by pins which make connections between the layers. Pins are either factory fixed, for the rear hard-wired connection, or inserted by the user at the front to establish routings. In its basic form therefore, the patch panel has no “normalling”. By the design of the exact lengths of the contact wafers, the precise patching and normalling possibilities are achieved.
Routing is achieved by inserting a plug into the lower row (the connection is made by the long pins on this plug linking the front and rear contact wafers). Patching does not break any contacts, so a “source” on the top row is simply patched to the “destination” on the lower row, just like a conventional jackfield. Effectively, with a plug inserted, the panel acts like a “half-normalled” jack field, which is the way virtually all jack fields are wired in use.
The major differences are that as there are no socket switch contacts, as in a normal jack-field, a possible source of noise is removed. Additionally, “sources” and “destinations” are in the no-load state until connected by a normalling plug or patch cord, unlike a jack-field where “normal” paths are chosen at system installation, which can result in unwanted normal paths at a later date.
All connections are 3-pole, fully isolated. The fourth pin on the patching connectors is a polarizing pin to ensure phase integrity, and performs no electrical function.
Unlike conventional jack-fields, Ghielmetti patch panels are suitable for use with both analogue and digital signals, even mixed within the same panel. Exceptional cross talk performance of over 120dB between adjacent channels (pro series) ensures that even low level digital signals pass with a minimal error rate, even when adjacent to channels with high level signals. Both balanced AES/EBU 110 ohm and unbalanced SPDIF 75 ohm signals can be handled.
The Economy range of lower cost panels omit the screening wafers that are fitted between adjacent channels in all other types. This reduces the adjacent channel separation to 80dB. Otherwise, they are similar in construction to the standard design.
Panels are available with various terminations. These are modular units that plug onto the back of the panel (one module per 8 channels, except SAG type which is one connector per channel), thus enabling cable termination to take place without the patch panel itself being present.
A special panel version is for RS422 or RS232 connections: this uses adjacent pairs of sockets effectively as one socket to connect all functions of the RS422 protocol, including the Sony-specific priority signal on pin 5 of the D-sub 9-pin connector. The stereo patch cords are used with this panel.
Certain models are available with electro luminescent strip front panel illumination. A special 230V AC power supply is included with each panel. These models are denoted by ‘Light’ in the order code.
3-pole normalling plugs are available in a variety of colors to assist identification. 2-pole normalling plus are also available for the purpose of normalling both signal legs but NOT the cable screen, e.g. for use in fault-finding. Locking normalling plugs are also available to deny access to the upper input connection for use where high signal integrity is necessary e.g. digital audio/data. Patch cords are available in mono (single channel) or stereo (paired channel) types.