In this age of digital studios, it is not uncommon to find several different pieces of equipment that utilize the lightpipe audio stream in a facility. With computer interfaces, digital consoles and, of course, ADATs incorporating the ADAT optical standard, the need for a patch system should seem obvious. With the introduction of the PBP-362 patch bay, Hosa Technology has “seen the light at the end of the cable,” so to speak.
Product PointsApplications: Studio, broadcast, post production, multimedia
Key Features: Lightpipe through and split capability
Price: $325 with one module
Contact: Hosa Technology at 714-736-9270, Web Site
The PBP-362 ($325) is a one rack-space, modular, multifunction patch bay system that processes ADAT lightpipe signals. The chassis can accommodate four separate modules. Each module has three pairs of lightpipe jacks, front and rear. The unit comes shipped from the factory with just one module, giving it the capability to handle 24 channels of audio. Additional modules (MFO-363, $250) can be added as the need arises. There is also a splitter module available (MSP-364, $85).
The MFO modules come configured for half-normalling operation but they may be reconfigured for non-normalling or straight-through function by repositioning a jumper on the module’s circuit board. In half-normalled operation, the top rear jack serves as the input from a source while the bottom rear and top front jacks act as outputs of that source signal. If you insert an additional source into the bottom front jack (unused in half-normalled mode), it creates two straight-through paths. The same can be accomplished by moving the module’s jumper to bridge pins two and three instead of one and two (factory setting).
It should be noted that Hosa recommends not using the PBP-362 like a traditional patch. This refers to the practice of sending an output from the bay back into another channel on the bay. Apparently, the lightpipe signal is difficult to reproduce or clone (which is what the PBP-362 does) and building a clone from a clone may produce unwanted artifacts.
Each module has three LEDs to indicate the presence of incoming signal on a lightpipe port. Power is delivered to the installed module via a wall wart type transformer (pos. tip, 7.5VDC, 1500mA). If you have additional modules, then the supplied daisy chain cable must be attached to provide power for them.
In setting up the PBP I installed the two additional modules that came with my review unit. This took about ten minutes with the supplied Allen wrench. The faceplate of the PBP is attractive even without all four modules installed. Empty module bays are covered with a black metal plate. It should be noted that there is no chassis housing for the PBP-362. This can be a double-edged sword as it allows easy access to the circuit boards and the jumpers but it also permits dust, smoke and moisture to reach critical components in the modules. (The manufacturer insists that all critical components are safely sealed and that standard maintenance with compressed air will take care of any unsightly dust build-up – Ed.) The PBP-362 comes with port plugs for all the lightpipe terminals – a critical place to keep contaminants out of.
I evaluated the PBP-362 in my project studio, using it to direct lightpipe signals between a digital console, a computer with a MOTU 2408 interface and a pair of 20-bit ADATs. (Manufacturer suggests using an external sync/clock when using possibly conflicting equipment – Ed.)
After purchasing a few additional lightpipe cables and a ten-minute hookup, I was up and running. I recorded some overdubs for a project I am working on. The part was a guitar arpeggio that went through the console to the PBP and then into one of the ADATs. From there I dumped tracks from the ADATs to the computer, via the PBP. All this was done with no audible artifacts and no detectable difference in audio quality. While I did make sure to use the shortest cables possible, I wondered if using long cables, both in and out of the unit, would cause degradation. According to Hosa at distances greater than 27 feet one should move from plastic fiber to a Glass Fiber Single Mode cable with amp/repeater boxes, e.g. Hosa’s OGC-361 ($499).
I found the PBP-362 to be a handy, time saving tool that was easy to install and operate. With a modest price and a high convenience factor, the PBP-362 is a bonus for any studio with a number of lightpipe devices.
Spirit 328 digital console; Pentium III computer with MOTU 2408 interface; Alesis XT20 ADAT recorder.