Image of Maestro Pro

Image of Maestro

High Res Version of Maestro Pro (1142 x 458)
Hi Res Version of Maestro Front (765 x 421)
Hi Res Version of Maestro Back (762 x 447)

The Maestro Pro is a full length Zorro II digital input and output soundcard with optical and coaxial iterfaces, the maestro is only a half length Zorro II card. It works with 16 bit and 32, 44.1 and 48 kHz. The only native software to support the Maestro Pro is "Samplitude" from SEK'D. There is a generic driver called maestrix.library from aminet as well as an AHI driver. The Maestro (ie not the Pro version) has digital input only.

Maestro Pro sound card Channel Swaping FIX!

Some Maestro Pro sound cards don't seem to be able to sample digital Audio without the channels swapping (at random) this can be seen best by setting the REC LEVEL of your DAT/(A to D converter) so that one channel is at a much lower level than the other, then recording some stereo sound with Samplitude, then when you view the wave forms for the right and left channels you will see sudden jumps and reductions in amplitude for the opposing left and right channels.

Apparently the Maestro Pro lacks A "Low Impedence Ground Plane", this is usually where there is an internal layer in the PCB that is connected to zero volts or Ground at each of the chips Hround pins and is usually a solid layer of copper. Electric current likes to flow back to Ground from the chips on the card, the same way that it got to the chip, so connecting any old wire may not work, it has be like a flat plane across the whole card.

THE FIX (as done by Simon Noble)

Well, I made a Ground plain from some prototyping PCB and soldered small off cut component legs to the MPro (see pic) these legs should be attached to the GND pins of all the chips on the MPro, I also did this to all the capacitors and any other component that had a Grounded pin, also where tracks passed through the PCB. This may have been over kill :-)

then having cut the Prototyping PCB into squares (to ease the fit over the cut legs) I soldered it down to the MPro.

MAKE SURE THAT YOU ONLY CONNECT THE GND LINES ON THE CARD TOGETHER
(test this with a continuity tester before you put the card back in you're computer). One wrong connection could destroy your computer. Check and double check!

Important Point: The Ground plane should be as close to the card as you can get it, mine was less than 5mm away. (see pic)

SIDE ON

Lastly but not least you should connect all the tracks on the Prototyping PCB together, I made connections at right angels to the tracks with more component legs (see pic) these were soldered to each track.

Thanks to Sebastian Schorch, Solon Lutz, Iggy Drougge, Simon Noble and NicDouille