Get audio data out of equipment. - Page 1
Forum section: electronics / projects

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 03, 2019, 03:55:31 pm
content: Hi, i like to get audio data out of synthesizers.These things are complicated, suppose i find in what chip the data is, how do i get the bytes out ?These synths contain multi-samples.Do i have to wreck these equipments before i can get it out ?, maybe i will.Or can i read all data without cutting and de/re-soldering ?I dont have a digital scope, i like to buy one for this project if it is needed.I mean, can i use the USB datalogger on a scope for this ?thank you

author: magic
author_rank: Super Contributor
timestamp: September 03, 2019, 07:08:16 pm
content: You want a realtime digital output or the samples?For the former, locate the DAC and intercept its input signal.For the latter, I doubt it's going to be easy and deliberate copy protection schemes may be in place to prevent cloning by shady competitors.

author: Bassman59
author_rank: Super Contributor
timestamp: September 03, 2019, 07:10:11 pm
content: Quote from: Jan Audio on September 03, 2019, 03:55:31 pmIf you want to get digital audio data out of a synthesizer that doesn't have a standard port for such (like USB), then the obviously place to start is at the DAC chip. RTFDS for the DAC to determine its digital interface (likely I2S, but there are others) and monitor it with a 'scope or data-logger. You might need to solder some short wires to the signal lines.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 04, 2019, 01:17:43 pm
content: The samples are stored in ROM, and figure out how the data is stored for each sample.First synth has ICs :3 x TC534000P ( 8 x 512Kbits ) , i think the multi samples are stored here.2 x 27C512 ( 8 x 64Kbits ) , what would be in here then ?I think the ROMS are degrading, build year 1989.

author: oPossum
author_rank: Super Contributor
timestamp: September 04, 2019, 01:35:03 pm
content: A TL866 can read those. The TC534000 isn't explicitly supported but it has a standard pinout so it can be read as a 27C040.It would be best to remove them for reading. Use a proper vacuum desoldering tool so you don't damage the PCBs.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 04, 2019, 01:50:48 pm
content: Ok thanks, so no chance to just hook up some gear.I will damage the PCBs because i am an amateur.I,m very bad with those vacuum things, i might as well not use it, it flys out of my hand.

author: oPossum
author_rank: Super Contributor
timestamp: September 04, 2019, 01:57:13 pm
content: Quote from: Jan Audio on September 04, 2019, 01:50:48 pmNot one of those, something like a Hakko FM-204 or FR-301.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 04, 2019, 01:59:02 pm
content: Thanks, only wow they are expensive, for that money i can buy oscilloscope.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 04, 2019, 05:02:26 pm
content: An alternative would be a temperature controlled soldering iron, some solder wick, some flux, and some patience.It takes some time, but it's entirely possible to remove through hole parts without a desoldering tool (or even with one of those cheap one shot solder pumps), you've just gotta take the time to do it and have the iron set low enough not to cook the chips.Of course you don't want to be dragging the wick around when removing the solder, and sometimes it helps to flux the wick directly for better wicking action. Yes, there is more potential for damage than using a vacuum, but it's entirely doable.

author: james_s
author_rank: Super Contributor
timestamp: September 04, 2019, 05:38:32 pm
content: It's just not worth it though, proper vacuum desoldering tools are just not that expensive, particularly the Chinese ones, some of which work ok.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 04, 2019, 06:28:44 pm
content: Even if you are able to read the chips it will not be very usable because the data will be compressed and encrypted. Been there, tried that

author: magic
author_rank: Super Contributor
timestamp: September 04, 2019, 06:38:16 pm
content: Quote from: Jan Audio on September 04, 2019, 01:17:43 pmThe first one appears to be a mask ROM, it isn't going to lose data.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 05, 2019, 12:21:19 pm
content: Quote from: PA0PBZ on September 04, 2019, 06:28:44 pmHi, what synth you have the datas from ?maybe you can email me if its not to big ?thanks

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 05, 2019, 12:32:26 pm
content: Hi Jan,The data was from an old drum computer (Cheetah md16), I didn't read the chips myself but someone else sent me the files and asked me to have a look.All I got from it was a headacheI'm not sure if I still have the data and also not sure if I should share because it is not my own data.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 05, 2019, 01:55:30 pm
content: Ah no problem, i dont need drums, thanks.Anyways i was thinking : how can these small ROMs contain all these samples, maybe i overlooked some bigger ROMs.And no problem i see these ROMS are socketed in online picture, hope mine is also.Next synth wont be this easy.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 05, 2019, 02:03:53 pm
content: Quote from: magic on September 04, 2019, 06:38:16 pmAh nice, i did not know this exists.Intresting.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 05, 2019, 03:34:45 pm
content: This thing has 19 adress inputs :https://datasheetspdf.com/pdf-file/1092402/Toshiba/TC534000P/1Anyone know how these work ?thanks

author: Bassman59
author_rank: Super Contributor
timestamp: September 05, 2019, 04:20:12 pm
content: Quote from: Jan Audio on September 05, 2019, 03:34:45 pmThese are the simplest things ever. Tie the chip and output enables low. Drive an address. The word stored in that address appears on the data bus.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 05, 2019, 04:25:00 pm
content: So i can use all 19 pins from 0 to -1 ?Then i can dump it into SD card, and done.

author: Bassman59
author_rank: Super Contributor
timestamp: September 05, 2019, 04:30:48 pm
content: Quote from: Jan Audio on September 05, 2019, 04:25:00 pmRig up something that can drive the addresses in sequence from 0x00000 to 0x7FFFF and capture each word. If you have an FPGA or microcontroller board lying around this is trivial. Design a serial port that transmits the address and the corresponding data back to your computer where it can be stored in a file or whatever.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 06, 2019, 10:43:36 am
content: Ok 0x7FFFF, will hook up a 40 pin 8bitter.First i need to spend some time with FAT32 for this SD card.

author: james_s
author_rank: Super Contributor
timestamp: September 06, 2019, 10:25:09 pm
content: Why not just use a proper eprom programmer to read them? Something like a TL866 will do it and they are under $40.

author: 2N3055
author_rank: Super Contributor
timestamp: September 07, 2019, 08:24:45 am
content: Quote from: james_s on September 06, 2019, 10:25:09 pmSeriously, what James said, I bought TL866 to repair single device. It was that cheap.I had to copy contents of Dalas chip with calibration constants..Then I realized it was full blown programmer that works really well.. Best buy thing ever.Used many times since.Just get one..

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 07, 2019, 11:12:44 am
content: Because mine is cheaper, cost nothing, already have the parts.Thanks+ i hate computers, USB and everything windows.

author: 2N3055
author_rank: Super Contributor
timestamp: September 07, 2019, 07:01:26 pm
content: Quote from: Jan Audio on September 07, 2019, 11:12:44 amFair enough. Good luck!