68kMLA Classic Interface
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| Pro Audio Spectrum 16 PatchPanel - Schematic Development for Reproduction | ||||||||||||||||||||||||||||||||||||||||
| Posted by: Trash80toHP_Mini on 2024-01-03 20:51:05 Saw this: working toward it. 😉 | ||||||||||||||||||||||||||||||||||||||||
| Posted by: smiba on 2024-03-27 12:16:39 Here is the uncropped and non-resized version of the image on my wiki (https://retro.woof.tech/index.php?title=Apple_Macintosh_IIci): View attachment DSCF1194.JPG | ||||||||||||||||||||||||||||||||||||||||
| Posted by: demik on 2024-03-28 14:44:34 As promised on the NUBUSPAS16-DB thread, here are my notes Connector Incomplete connector pinout, card side
__________________________________
\ /
\ 09 08 07 06 05 04 03 02 01 /
O \ 18 17 16 15 14 13 12 11 10 / O
\ 26 25 24 23 22 21 20 19 /
\________________________/
01 MIC L
02 MIC R
03 IN1 L (Crosstalk at -20dB ?!)
04 IN1 R
05 GND
06
07
08
09
10 IN2 L (Crosstalk at -20dB ?!)
11 IN2 R
12 IN3 L (Crosstalk at -20dB ?!)
13 IN3 R
14 GND (Digital)
15 +12V
16
17
18
19 IN4 L (Crosstalk at -20dB ?!)
20 IN4 R
21 OUT L !
22 OUT R !
23 GND (Joystick ?)
24
25
26Other informations: - only +12V found, no -12V (audio) or +5V (MIDI, Joystick). Either theses are generated on the patch panel, or the card is off spec. - joystick seems to be doable without much component, but don't know enough about theses - I got a bad crosstalk (-20 dB !) when using the left channels of line in 1-4 - the MIC input is actually a stereo line input. Some circuitry on the patch panel do the microphone preamp part and convert that to a stereo line signal Test points A few test points around op amps
Other informations: - U11B is likely a buffer op amp for the OPL - Miximg op amps are gain 1, with 20kΩ + 20kΩ feedback - Inline outputs resistors are 47Ω - U15B is analog switch. For muting inputs ? Misc - No idea about the custom IC (Thunder) on the left. It's somewhere in the audio inputs paths and maybe line out as well - Microphone preamp is maybe discrete, maybe using the custom IC - headphones amp is discrete - either it's generating -12V from the +12V or all pampas are braised and DC coupled (= bad). U5A or U6A ? - I'm 90% sure, besides power, that the joystick lines are on on the card. Some go to the NE558 IC, which, was used with some PC Joysticks - no idea about MIDI, but it probably need some opto couplers - don't understand what the LF347s are for. They are duplicating a signal, that's sure. DC biaising ? Hope it helps | ||||||||||||||||||||||||||||||||||||||||
| Posted by: smiba on 2024-05-10 13:30:57 Would it be of help if I open up the patch panel I have and make some pictures of the PCB? I have a full set | ||||||||||||||||||||||||||||||||||||||||
| Posted by: Unknown_K on 2024-05-10 14:24:47 On the Pro Audio Spectrum 16 ISA card some of the custom chips are just relabeled parts from other manufacturers. https://www.dosdays.co.uk/topics/retro_review_pas16_pt2.php | ||||||||||||||||||||||||||||||||||||||||
Posted by: demik on 2024-05-17 10:56:29Would it be of help if I open up the patch panel I have and make some pictures of the PCB? I have a full setNot for me, but it may be interesting of other people show up. I wouldn't bother to open it if not needed as the plastic may break On the Pro Audio Spectrum 16 ISA card some of the custom chips are just relabeled parts from other manufacturers.Thanks. Nice article! Unfortunately the chip on the patch panel doesn't seem to exist on ISA cards | ||||||||||||||||||||||||||||||||||||||||
| Posted by: stynx on 2025-11-23 02:57:59 I recently got a PAS16 NuBus in box but without the cable. The original owner lost the cable in the mid 90s and has put the card back in the box because of that. Is the cable 1:1 or has it some custom pinout on either side? Is the cable insulated or are some lines specially coupled? -Jonas | ||||||||||||||||||||||||||||||||||||||||
Posted by: stynx on 2025-11-23 02:59:55  | ||||||||||||||||||||||||||||||||||||||||
| Posted by: Trash80toHP_Mini on 2025-11-23 11:15:00 Glad to see more activity on this front again. Been wondering, is the PAS16 setup better than the G3 system/personality card, same or less capable? | ||||||||||||||||||||||||||||||||||||||||
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