The Alpha I Tower I received this past week had the sound card along with a PIII 550E processor. This one was from November 2000, my new Alpha II case was April 2001.
Huh? Can you remind me please, bearing in mind I have never needed to build a kit from scratch............
I drew up a partial schematic for this card. I obviously can't figure out the capacitance values of the capacitors from pictures and the unpopluated schematics but I just put in question marks for the unknown values. I also used resistor symbols for the capacitors because I can't find the proper symbols in the libraries I have (They're probably there but I'm an idiot). It would be awesome if someone could get the capacitor values but I know that's a lot to ask because someone would have to remove them from circuit. I've tried to figure them out from the datasheet but it doesn't give many clues. By no means am I an electrical engineer or an EAGLE expert so don't expect this to be perfect. This doesn't include connections to two components I can't identify. From the pictures I have I believe one is labeled "7z66g" on the front right side of the board about an inch up in an sc70 package. I also don't know what the yellow thing is directly above the marking on the board that says "+3.3VD" I also have designed the AMR slot package to specifications according to the PDF. I don't really know what I'm doing so don't expect this to be very accurate. I have most of the parts on the way for a franken-alpha. Maybe when I have the funds I'll try to make this board if I can finish it. Edit: I should also mention that I have not yet included the audio out port. I have to find the library or create my own part. If i were to to do this I would probably use a modern, readily available audio port. Also in reference to the AC97 codec component I used, It's a 9707 as opposed to the 9701 because it has an identical pinout with the exception of a few extra features. Double edit: I'm pretty sure the yellow thing is just a jumper and the mystery component is an NC7SZ66. I'll post completed schematics (excluding resistor and capacitor values) sometime tomorrow. Triple edit: Here's what I believe to be the completed schematics http://i.imgur.com/baUqyrx.png
J15 [-] +5VD [-] [ ] +3.3VD X1 GOLLEDGE 24.576MHZ MS03509 L2 000 U1 WM, WM9701A, 06AAXFR U3 78L05A, ST, K005 U4 7Z66f C52 10uF 50V C53 10uF 50V C49 10uF 50V C06 10uF 50V C38 10uF 50V C28 2.2uf 50V C35 2.2uf 50V C37 pink C30 pink R33 2200 R34 4782 R36 2200 R37 4782 R45 1002 R57 49R9 C50 brown C51 brown C45 brown C43 brown C40 brown C34 pink C33 pink R32 49R9 C27 brown C15 brown C32 brown The metal bracket is stamped: 5001, Globe, NJ 07092 800-227-3258 http://www.globebrackets.com Global HQ Globe Manufacturing Sales, Inc. 1159 US Route 22 East Mountainside, NJ 07092-0213 sales@globebrackets.com Tel: +1 908-232-7300 Fax: +1 908-232-5202
Thanks a ton! I found a few mistakes and missing things in my last schematic but I think I have it finished correctly now. I'm in the process of designing the board to AMR spec. Should hopefully have it posted soon. Edit: I'd like to rearrange the components so everything is a little neater. I also need to mess around with the settings in EAGLE to change the trace clearance because nothing will connect to the AC97 codec chip. The resistors and capacitors are not surface mount in my design but I could easily change that. I have also included the schematics, board file, and libraries I have used up to this point in case anyone is interested in them. If anyone finds errors in the schematics please let me know! https://mega.co.nz/#!p99VwJAZ!JxAz3vo5p-4p9ISpaVT3pSyEW8P6iauD-FAI_42126A
I'm glad to see others making progress on this. Hopefully a solution is near. I've also been working on this in my spare time. The first board rev is nearly done and I'll be sending it to the fab in about a week.
If nothing else we could probably drill a hole in a blank bracket... wouldn't be nearly as cool though. @aspect What would it cost to have a board like that fabricated? The sites I was looking at were saying $200+ for a single two sided board.
My intention is to break out the two channels of audio out to RCA jacks to ease connecting to a TV. Still looking at candidate PCI brackets to help with this. Less than $50 for three. There are a number of discount fabs out there that'll do boards for dollars per square inch. Finding one that will gold plate the connectors (for the bus edge connector) is the real differentiator. Here's a great list of some of them: http://www.ladyada.net/library/pcb/manufacturers.html
Every time I've used my Alpha's it was with a LCD screen via VGA, yes it has S-video but I've never used it, so if you went with RCA jacks that would make it difficult to use PC speakers without an adapter. I'd stick with the original audio jack. Also there is a pre-Alpha case on eBay thats overpriced, basically what they looked like before MS painted them and slapped a piece of aluminum on the front. 321433356148 for those interested in a case for their franken-alpha.
My current PCB just has a four pin header which different connectors could be plugged in to. It wouldn't be too hard to fashion both RCA connectors and a 3.5mm jack output using the same card.
@aspect your schematic looks really nice! It would be nice if you could contribute it to the Github Repo of CodeASM (https://github.com/CodeAsm/AlphaSound) so we can all profit from your work. Of course, only if you want to.
I'll think about releasing the files once I've completed and tested the design. There's quite a lot of work to do before that can happen. I'm about a day or two out from sending the layouts to a fab and ordering all of the passives and the Wolfson chips. Currently need to track down a reliable supplier for those.
@aspect Okay, thats something I understand! I hope that everything is working out fine. Good luck, hope these chinese resellers are selling original chips.
The PCBs and components arrived last week. I assembled a board quickly as a proof of concept and it, a little surprisingly, works. I can get audio out of the dashboard's music player, where previously the audio player would just refuse to play anything. I haven't yet loaded a game onto my alpha kit to test that out. I'll give that a shot after the weekend. The audio path is super noisy. I'm going to make some revisions and get another spin of the board. I can confirm that the more available WM9707 chip works fine. I ordered mine from mouser. I believe the only difference between it and the WM9701 is the number of available outputs. Please excuse the state of the board. I wasn't terribly careful. I still have every intention of getting these in the hands of people who want them.
Load the Simpson's game for the test, as the other game for Alpha's crashes too much. Can you make a video so I can hear the noise, oscillator maybe?
Sure, I'll make a recording when I run the Simpsons game. It sounds like it's not isolating noise from the PC very well since the whine changes in pitch as load is placed on the CPU and/or GPU. It could be that some parts are too close to the GPU. It also certainly could be noise from the digital side of the card. I didn't fit the analog side power supply inductor that the documentation indicates since I didn't see it fitted to the actual engineering cards people have photographed. That's probably where I'll start.
