Search found 23 matches

by av500
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...
by av500
23 Feb 2024, 14:16
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]

agung wrote: 23 Feb 2024, 14:15 Oke thanks.. Your update schematic look like different for value part and others with Stephanovitch layout.. Please tell me, which one we must follow?
actually Stephanovich edited the file, I just posted it.
by av500
23 Feb 2024, 10:35
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]

looking at my original photos it's +/-15V
agung wrote: 23 Feb 2024, 09:57 Hi thanks
Are you sure u9 and u10 supply voltage 5v simetris, ? Or 15v ? It's tlc2272
by av500
23 Feb 2024, 08:55
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]

agung wrote: 23 Feb 2024, 04:22 Hi
Iam plan to build layout for this. Anybody can tell me for c1 and c2 value for BUZZ area?
see here:
Sansamp_PSA1_schematic_fixed.png
by av500
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...
by av500
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...
by av500
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...
by av500
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]

bajaman wrote:says it is corrupt even when renamed
yeah looking at the actual binary data, it looks fishy. guess something went wrong reading it out. back to the drawing board...
by av500
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]

Dirk_Hendrik wrote:Why not?
well, I don't have any idea what the legal implications are. so I err on the side of caution...
by av500
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...
by av500
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... :(
by av500
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
by av500
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...
by av500
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...
by av500
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...
by av500
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...
by av500
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...
by av500
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]

DimebuGG wrote:Schematic redrawn...
wow, thanks for redrawing this! :applause: :applause: :applause: