Sorry people, but I am still waiting for infos
about some chips. In the meantime some brave souls amongst you may
try to build a pre-amp (or have a spare one in a drawer) and attempt
what is described below, that is to grab the analog signals, amplify them
in order to keep a decent S/N ratio before delivering the audio outs to
the external mixer. Consider this to be a guide though, I have no specs to
give as far as components go, please tell me if
Keep in mind that althought it is not difficult, maximum care must be taken
when performing this kind of customization, in order not to fry your
computer or card or whatever. Although it seems unlikely to me, the
implementation of components might differ from version to version, so
check the connectivities first to make sure you are on the right signal
path. For example, make sure the left out from one chip goes to the
left in of the following one, after passing through OP AMP, resistors
and more condensers...
If you haven't done so yet, read the
preliminary notes and get the
datasheets to make sure you know what you are
doing and more importantly, to check whether I made any mistake. Also,
getting help from friends in the electronics sphere would be a really,
really good idea.
From here on (actually, right from the beginning), the orientation of the
card is assumed to be : audio I/Os on the right and ISA connectors at the
bottom, electronics facing you.
The Wavefront Sub-Hack
You should know by now that NEC ÁDP6376 is the DAC
for the Wavefront synth. The DAC is located to the right of the IDE
connector. This is also where the OPL3 and its DAC, as well as the quad
OP AMP C084 are clustered. I could work out the ÁDP6376 connections as
Fig. 1: ÁDP6376 pins.
You "just" have to draw some wires from the L and R outs to the ins of
your pre-amp with as short paths as possible, probably shielded too. If you
are luckier and have a DAC in your drawer (from a broken CD player), you
may try to pick up the digital data (LRCLK, SERDATA and BCLK), send them
out and DAC them outside the computer. It seems easier to me to derive the
signals from here because there's more "room" to perform a modification
than in the periphery of the WF chip itself.
Discussions on how to concretely achieve either transfos
The FM Synth Sub-Hack
I'm aware that it sounds kind of "exotic" to
try to improve the FM synth part, but it's nevertheless 24 more
voices, isn't it ? And if it is separated, it can be passed
through external gears to deepen/thicken uzw..., cook it. The dedicated
DAC is called YAC512 and needs two external OP AMPs to trigger
sampling/conversion. Here it goes:
Fig. 2: YAC512 pins.
The audio signals CH1 and CH2 correspond (on my card) to right and left
respectively. The maximum output amplitude is 2.5V according to the
datasheet. There again, if you have a handy pre-amp, it should be straight
forward. Less obvious might be the external DAC route. As you can see from
the YAC's datasheet, it is not a standard format. So the only way to go is
the YAC way, i.e. you can not choose your favourite DAC... Unless someone
comes up with a brilliant
Flee to Main Stage.
You missed the whole story ? It's here.
Get more detailed infos from Chips & Tricks.
Have a look at the actual work and the