Sound loss on custom Performa 637

[CC_333]

@Trash80toHP_MiniCongratulations! This almost makes me want to get a 6400 just to see (hear?) what all the hype's about. Almost.

@LaPortaI wonder if there's normally some kind of ground connection in the wiring harness that has become disconnected somehow? It seems dumb that it would work fine without a ground all this time, and then suddenly not work unless grounded?

I have somewhere a spare harness I could send you, if you want to test this out?

PM me if interested.

c

 

[LaPorta]

I believe that it always needs grounding. Looking back in older photos, it was up against the floppy chassis, grounding it. When I moved it, that was gone. The box normally inserts into part of the metal chassis, which in turn contacts the power supply. With it all torn apart, that connection is lost. 

 

[Trash80toHP_Mini]

@Trash80toHP_MiniCongratulations! This almost makes me want to get a 6400 just to see (hear?) what all the hype's about.

Thanks. If you haven't got an Apple TV/Video System MedusaMac in your collection, get one. The 6400 is the one to get as it's a one way board swap 6500 "upgrade." I'll have to test the AM/FM Tuner box at long last, never did try it out in the 24 years I've had it.

@LaPortaI wonder if there's normally some kind of ground connection in the wiring harness that has become disconnected somehow? It seems dumb that it would work fine without a ground all this time, and then suddenly not work unless grounded?

I'm sure LaPorta is right about chassis ground connection being a requirement for proper function, else the PCB inside wouldn't be soldered directly to the side/bottom of its can. I think we should consider the results I've gotten a question mark for rigorous testing. Heaven only knows when my setup was coincidentally touching the chassis. It could also be a logic board model variable? My setup is designed for easy access testing of the entire Quqdra 630 mobo drawer series right up to the 6500/TAM Gazelle logic boards..

I have no photo references as I'm not doing any documentation of my BenchMac/MaxiTAM of that type until the bench is cleared for Alchemy/Gazelle testing of PCI card compatibility and the Riser development project.

I see the 6500/TAM Gazelle Architecture as analogous to the IIfx flyer in the Macintosh II grouping. Both are akin to experimental testing of higher velocity loads against the tried and formula of a well tuned varmint rifle. The significantly higher bus clocks place rounds on target faster, but fail to hit the center ring reliably.

 

[Trash80toHP_Mini]

Success! First test of the day has the 6290(?) driving the Ersatz Bose setup of my MaxiTAM BenchMac very nicely. []

@LaPorta could you test one of your Quadra 630 boards in the 6400 with powered speakers and balanced subwoofer stereo enhancement? With a 6400/6500 Audio/Monitor Connection Subassembly infusion, any matched impedance sub driver and a box for it might be tucked away in your custom case? An external box to match a pair of powered speakers could be very nice too.

 

[LaPorta]

The issue I have is the 630 MBs did not function in the 6400. There must be something about it that is not compatible.

 

[Trash80toHP_Mini]

I thought testing the two 630 boards in the 6400 and got sound was how you discovered yours was not a logic board problem? Are you saying the 630 won't drive the sub balanced with the externals? They have to be plugged into the rear jack for it to work correctly, which way did you test in the 6400?

BTW, I think I now have a new CD player setup in the bedroom, switched the multi octave testing "pieces of you" Jewel CD out for "No Exit" and the baseline of Blondie's "Maria" is simply amazing! []

Now I understand the TAM/Sound System fixation, that Bose Acoustimass Speaker/Sub setup must be incredible for a computer speaker system.

 

[LaPorta]

No, I tested it in my 6300, which had the exact same hardware as a 63x. The 6400 wouldn’t even start or display an image on the monitor with the 63x board.

 

[Trash80toHP_Mini]

HRMMM? Most interesting. :huh:

Is the OS installed on the 6400 Q630 compatible?

It the monitor setting on the 6400 Q630 compatible?

Do you have an OS install CD available to boot the 6400 from with video set to a compatible resolution?

I can't imagine the Q630 board not working in the 6400 hardware state with those two variables in line with its capabilities, but it could be something I'm missing?

 

[LaPorta]

Likely something else going on. Nothing from the 6400 at all. OS/CD would make no difference, as the screen should at least come up.

 

[Trash80toHP_Mini]

Dunno, there's always a lag, the screen doesn't come up from onboard video until the drivers load from ROM or Disk? I'd think it would at least come up in 640x480 even if the system/logic board combo is whack, but now I have my doubts about that.. I'll have to test mine when & if I can find the damn thing.

Apple TV/Video System is up and running on the 6500 board from the 8.1 partition on the test drive. The installer floppies that came with it don't even recognize the OS9 partition? It "just worked" on a random dive that's probably from the 6290 that I must have had in the 81/100 with VideoVision Studio at some point. Crazy mix of stuff on there and only one document.

Hooked up a spare nine year old DVD player from a hacks project. No S-Video cable handy but it looks passable from composite. Was really testing sound quality and that's just great, I'll compare its sub-enhanced goodness to what I get from the HDTV speakers alone off a real HDMI DVD feed. Can bop back and forth on the inputs, but I'm afraid that'll have me recapping an ancient 5.1 receiver and adding yet another remote to the nightstand. :

It's only a busy looking 27.75 inch diagonal 4:3 picture on the 800x600 desktop which though a bit distracting, is the largest screen I've had from anything in the collection to date. Gotta go through the HDTV manual to see if I can get it to display exact;y what I'm throwing at it all centered up. Too many inputs are close, but no cigar or even farther off target. Not a great computer monitor so far, but it does rock 800x600!