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-   -   BOSOZ help needed (http://www.diyaudio.com/forums/pass-labs/69426-bosoz-help-needed.html)

lgreen 9th December 2005 07:46 PM

BOSOZ help needed
 
I've managed to get a pair of Kari's X-CCS-BOSOZ boards and put them together.

Problem is that the L/R channels don't use any power, after turing the thing on, and off, the power does not drop, and there is no output. Overnight the + rail went from +60 to +54 for example.

Link to schematic.

Link to image of my board

Perhaps I oriented something incorrectly?? the + and - DC inputs? The MOSFETS? The voltage references?

I don't think that there were any errors on Kari's L/R preamp boards (unlike the 2 on the power supply) but I could be wrong.

edit- the power supplies are working, +60V and -8V DC. The 22.1 ohm resistors are under the board so you don't see them. I have no grounds connected to the inputs and outputs, yet (no signals going in or out at this point) figured that the DC power supply ground would be sufficient to get it up and running, and that one is connected.

anyone?

steenoe 9th December 2005 08:03 PM

Quote:

Link to image of my board
Pretty sight:) Do check your wiring again! As far as I know, the boards are supposed to work. Did you swap in/out wires with the ground wires or something like that? I just happened to do that on one channel of a preamp:xeye: Take a really close look at all your wiring. I just built the Twisted BosoZ, which is based on Kari's schematic, and it works (wonders!) Good luck:)

Steen:)

lgreen 9th December 2005 08:09 PM

Quote:

Originally posted by steenoe
Pretty sight:) Do check your wiring again! As far as I know, the boards are supposed to work. Did you swap in/out wires with the ground wires or something like that? I just happened to do that on one channel of a preamp:xeye: Take a really close look at all your wiring. I just built the Twisted BosoZ, which is based on Kari's schematic, and it works (wonders!) Good luck:)

Steen:)

Yeah, I checked the wiring. Hmm.....is the silkscreen ok on those boards? anything shown backwards?

I'll take some DC measurements and post results if this can't be solved asap.

steenoe 9th December 2005 08:19 PM

Quote:

Hmm.....is the silkscreen ok on those boards? anything shown backwards?
Come to think of it, not many people reported about finishing Kari's BosoZ! Maybe there could be a mistake somewhere, as there is on the PSU board? I guess you catched the one on the PSU??

Steen.

hifimaker 9th December 2005 08:30 PM

Search Kari's board thread. There was an error with the diodes in the PS.

-David

steenoe 9th December 2005 08:46 PM

2 Attachment(s)
Quote:

There was an error with the diodes in the PS.
Yep, I quote: Important! The diodes on the positive side has a silkscreen error! Just turn the diodes 180degrees and you should be fine.
Also D9 and D10 are connected wrong. Please connect them as the picture here:
I just took a pic of the pic from Kari's homepage:D Hope you can see it:) Luckily enough, I did print it out, when the homepage was still running:) Here you go:) Hope this is the answer!

Steen:cool:
Sorry if this is the problem, I took it for granted, that you knew about it!

lgreen 9th December 2005 08:54 PM

Re: BOSOZ help needed
 
Quote:

Originally posted by lgreen
***
I don't think that there were any errors on Kari's L/R preamp boards (unlike the 2 on the power supply) but I could be wrong.

edit- the power supplies are working, +60V and -8V DC. The 22.1 ohm resistors are under the board so you don't see them. I have no grounds connected to the inputs and outputs, yet (no signals going in or out at this point) figured that the DC power supply ground would be sufficient to get it up and running, and that one is connected.

anyone?

I wish!!!! actually I caught the errors in the power supplies and fixed them as per everyone's posts. So its not that....

steenoe 9th December 2005 09:10 PM

Quote:

So its not that....
Darn:bawling: Well, I have a pair of Kari's boards too:) I will try to see if I can solder them up, next week and find the faults, if there are any! At this point I cant offer you better than that:) I recommend that you check the wiring again, though:xeye: Could someone please give a link to a working preamp of Kari's?? Please come forward if you know of one!

Steen:cool:

lgreen 9th December 2005 09:41 PM

The only other attempt at Kari's boards that I know if is by dhole
here.

I just replied, wonder if he got them working.

AR2 10th December 2005 06:26 AM

Maybe the fact that Colombo is not delivering parts from the group buy is not as bad. Otherwise we all will be pulling our hairs.
Sorry Lgreen
:devilr:
I still hope for the parts so I could join you in finding the problem. This whole thing was a problem - long wait for the boards, mistake on boards, no parts... Unfortunate. And I have 6 boards!!!


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