525 build thread

[duantro]

Sorry I meant i was probing on A1. corrected that typo.  I'll try lifting the wiring from A1 output to the output pot and see if signal comes back
Edit: I lifted wire labeled #1 from meter board, assuming it is the connection from A1 output to the output pot. It sure is fun trying to figure out where all these traces lead without any schematics correlating to the off board pcbs, besides 1 goes to 1,...Anyway I am still not getting VAC on output of A1. I'll try to reflow some solder on the pins of A1sockets...

 

[duantro]

That didn't do anything. swapped out 2520 yet again- nothing. I'm geting +_15vdc on A1 pins. Found a broken ground wire that went to SW5A pos 0,.... got excited,... re soldered, and still nothing. Must have been a casualty from all of the assembling/ disassembling. A ribbon connector ala 4kcc sure looks smart now. I'm going to have to walk away...

 

[dmp]

Did you pull A3?
Swap Q1?

 

[duantro]

Yes, pulled A3, and just swapped Q1, I know it's got to be something simple, but I'm at a loss

 

[dmp]

What value is R7 trimmer?

 

[dmp]

Something around A1 is messed up. Since you have another one that works, compare everything around there.

 

[duantro]

R7 is 5k. It looks like I'm not getting input to A1 Let me trace through it. Thanks for all of the suggestions.
Edit: A4 does check out. Signal is making it to  the side towards the edge connector of R1

 

[duantro]

Q5 emitter- base gives me .6vdc

 

[HerbertR]

View attachment VID_162092953185F.mp4
Hi, I bought a old Rev.1 PCB a few weeks ago of the LAZ525 at the Black Market and built it. Really lots of components and cabels for a 500 Unit. To get this piece working there are a lot of Mods with the
old Version to do. But not a real big challenge. The sound of the this piece is really fantastic. On Vox and Guitars this piece is a real Competitior to a 1176. Mid forwarded, slightly open and snappy, with the typical API Vibe.... Whithout any doubt, fantastic!
Someone should sell that PCBs again. This Design is much to good to disapear in the drawer....

 

[Rob Flinn]

View attachment 80785
Hi, I bought a old Rev.1 PCB a few weeks ago of the LAZ525 at the Black Market and built it. Really lots of components and cabels for a 500 Unit. To get this piece working there are a lot of Mods with the
old Version to do. But not a real big challenge. The sound of the this piece is really fantastic. On Vox and Guitars this piece is a real Competitior to a 1176. Mid forwarded, slightly open and snappy, with the typical API Vibe.... Whithout any doubt, fantastic!
Someone should sell that PCBs again. This Design is much to good to disapear in the drawer....

That is the first board Peter did, the second version was slicker & much easier to build. I have both. Peter disappeared after this. The last I saw of him was when I met him for a few beers in west london maybe 8 or 10 years ago.

 

[Sspxp]

how close are one of these to the 525

im interested but it looks like the guy is MIA too

seems to be the only 525 clone made

 

[Potato Cakes]

It is the original schematic with an added attack control. It calibrates per the original manual. The differences will be what is decided for op amps and transformers. Also, when asking how close is it to a real (insert vintage piece of gear) one has to also specify which serial number they are referencing.

Thanks!

Paul

 

[Sspxp]

i mean like is it more similar to the reissue or vintage one? if those are different

no preference, but theres not a lot of documentation on this clone since its not as popular

 

[Potato Cakes]

The schematic used is the original, so I suppose the answer would be the vintage version.