Search found 23 matches
- 12 Mar 2024, 14:18
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
but how will you MIDI control it???
- 24 Feb 2024, 08:10
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
There are still some wrong bits to the puzzle ;-) There is no 47n followed by a 100k to ground between U9a and U9b in the "secret" section - U9a output connects directly to U9b input ;-) I wonder what those 14 pin devices with the sanded tops are - they appear to be supplied by the +5 and...
- 23 Feb 2024, 14:16
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
- 23 Feb 2024, 10:35
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
- 23 Feb 2024, 08:55
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
- 08 Feb 2021, 19:07
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
Hi all! Looking for someone who could pull the firmware out of his (hers) PSA-1's eeprom. I've got faulty PSA-1 that fails to boot. p.s. have a response from SansAmp guys that the'd try looking for one, but I'm afraid it could end with nothing (you know, besides digging in a pile of old design file...
- 16 Aug 2017, 16:21
- Forum: DIY Projects
- Topic: Baja Music Man guitar and bass onboard preamps [documentation]
- Replies: 503
- Views: 183913
Re: Baja Music Man guitar and bass onboard preamps [documentation]
TI is stopping the LM4250 production, stock up while you can
https://tech.ebv.com/PCN/pcns_show.php?pcn=1502911127
https://tech.ebv.com/PCN/pcns_show.php?pcn=1502911127
- 22 Jun 2017, 09:53
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
turns out it was not the EPROM device but the PC, after unfreezing another XP machine with a working parallel port from cold storage it worked...
- 21 Jun 2017, 14:13
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
darn, the EPROM reader does not work, it always reads the upper and lower 4 bits the same and of course it's 20ys old with no support...
- 21 Jun 2017, 12:47
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
yeah looking at the actual binary data, it looks fishy. guess something went wrong reading it out. back to the drawing board...bajaman wrote:says it is corrupt even when renamed
- 18 Jun 2017, 09:39
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
well, I don't have any idea what the legal implications are. so I err on the side of caution...Dirk_Hendrik wrote:Why not?
- 17 Jun 2017, 16:23
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
Hey, how is the dumping going? I'm really looking forward to it! I wrote a little disassembler which lets you analyse the contents of the EPROM. I was hoping to fix the broken bytes by the help of that, but it seems there are just too many of them. :( You can find the source code here: https://gith...
- 04 May 2017, 11:51
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
slowly since coworker decided to give it to a friend so I am waiting for the EPROM reader come back...
- 17 Apr 2017, 16:14
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
I have a working PSA 1 and an eprom reader so I will try to dump it next week
- 29 Mar 2017, 08:15
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
before you burn another transformer, check the board for a short to GND on any of the three power rails: 1) measure the resistance to GND on the three regulators, 5V, 15V, -15V on both input and output pins, see the internet for the data sheets (7805, 7815, 7915) 2) check the capacitors in the power...
- 27 Jul 2015, 10:44
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
Further question, av500, on your sketch of the amplifiers circuits you list the unknown IC's (ones with the code ground off) as DS1267. I'm sure that somewhere else on a forum (perhaps this one) I saw that conjecture was that these "unknown" IC might be opamps. Can you expand on how you d...
- 21 Jul 2015, 09:22
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
remove the transformer and then measure the resistance to ground of the +/- 15V supplies. The transformer and regulator overheating means that you most likely have a short circuit to ground. if you indeed find a short, the game is to find what part causes it. remove all caps first, they can go bad e...
- 12 Feb 2015, 14:53
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
From that to another topic: Those diodes... In back-to-back configuration like that they pretty much have to be Zener type. What's the Zener voltage? Close to supply rails or much lower? It's a somewhat important detail. I just checked, the diodes are marked 1N5230B which makes them 4.7V types: htt...
- 11 Feb 2015, 22:13
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
From that to another topic: Those diodes... In back-to-back configuration like that they pretty much have to be Zener type. What's the Zener voltage? Close to supply rails or much lower? It's a somewhat important detail. thanks for the insight, I'll have a look at the zeners and report back here. O...
- 11 Feb 2015, 22:00
- Forum: Boutique Stompboxes dissected...
- Topic: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
- Replies: 69
- Views: 82057
Re: Tech21 SansAmp PSA-1 PCB traces and schematics [traced]
wow, thanks for redrawing this!DimebuGG wrote:Schematic redrawn...