API 312 Thread!

[ask]

First, a thanks to Fabio, and all supporters! :sam: :thumb:

re 512: Would a Jensen™ JT-115K-EPC fit the (fabio) board, it's a 1:10 that Eisen specifies for their 512 clone?

"northsiderap" mentioned a jensen 115, but not which type. Are you still out there?

Are cinemags the only trannies with dual impedance?

re DI: Would there be any issues in installing a JLM DI, so that the DI signal travels through the I/P tranny?

 

[BR]

Hi ask,

re DI: Would there be any issues in installing a JLM DI, so that the DI signal travels through the I/P tranny?

you bet. I'm doing that on my next pair. It's probably the best way. (disclaimer: the before mentioned is only an opinion, not fact)

Gil

 

[ask]

Thanks.
So it's DIYable? Does anyone know which "fabio"-parts could be left out, when skipping the standard DI?

[quote author="BR"]Hi ask,

re DI: Would there be any issues in installing a JLM DI, so that the DI signal travels through the I/P tranny?

you bet. I'm doing that on my next pair. It's probably the best way. (disclaimer: the before mentioned is only an opinion, not fact)

Gil[/quote]

 

[JLM Audio]

re DI: Would there be any issues in installing a JLM DI, so that the DI signal travels through the I/P tranny?

The JLM DI will work fine in there. Just cut the cable coming from the input XLR and wire it in and give it +12v to +48v and your done.

 

[BR]

hi ask,

just look at the schem and find the section with all the DI components and leave them out, or pull them.

here is the schem:

http://www.braudio.com/product_files/CAN312_schem.pdf

Let me know how it turns out. I'm planning on doing the same thing.

 

[drpat]

...

 

[mhartman]

I'm having a problem with Bauman's 312 PSU that I'm hoping you guys can help me out with. I put it together using Greg's BOM. I just hooked it up earlier today and the + and the SW outputs are dead on. The - output, however, won't go any higher than 13.6V (9.5 is the V when the adjustment is at its midpoint) and the 48v rail is only reading 26V. Anyone have any idea what I screwed up? I have checked it over and I don't see any short or anything installed in the wrong place or backwards. Any help is greatly appreciated.

Mike

 

[louder]

alo
is the power tranny correctly connected?.
best regards
pedro

 

[mhartman]

Thanks Pedro.

I'm fairly certain that I have the power tranny wired correctly. I used the Amveco from the BOM and I wired the red/yellow violet/black to the AC common and hot. Then I wired blue and green to the outer inputs "~" and red and brown the the inner inputs "G". This is how it looks like others are doing it.

I am getting 26VAC from both when I take a reading from green or blue to the brown/red wires.

 

[louder]

alo
looks fine.
did you ground the psu?
best regards
pedro

 

[mhartman]

No, I didn't do anything with the ground wire from the socket. How do I wire the ground prong of the AC into the system? Thanks again for your help.

Mike

 

[Greg]

Did you pull the 5V from the R1/C1 juntion, or did you build it exactly as it is on the PCB?

 

[mhartman]

[quote author="Greg"]Did you pull the 5V from the R1/C1 juntion, or did you build it exactly as it is on the PCB?[/quote]

I built it exactly from the PCB/Parts list. I saw some messages regarding changing something in the R1/C1 junction, but didn't really get the drift of what the change is. Would you mind elaborating what the change is?

BTW, does anyone know what part would cause my negative 15 rail to be low on power (13.6V max)? The positive rail and the SW rail are perfect, it is the the 48V and negative rails that are too low.

Thanks,
Mike

 

[3nity]

why wouldn't you post a pic so we could take a look?? i'm gonna fire mine maybe tomorrow!

 

[mhartman]

Good idea. I'll upload it when I get off of work.

BTW this is my first DIY project. I was just happy that it didn't blow up in my face. But, I would like to get it working so I can hear my API pres.

Mike

 

[mhartman]

Here's a pic of the PSU. I am aware that I'm somewhat of a hack, it's my first PCB assembly. I hope to be a bit better when I get to the JLM boards for the DI/Go Betweens.

Thanks again for the help.

Mike

 

[spica]

Does anyone have a good pic or two of how they have everything grounded? I'm having some minor ground hum and am having some trouble getting it smoothed out. For reference, I have 4 312s and the power supply (which I don't think is introducing any noise itself) in one box. I'm a bit confused with the difference between "audio ground" and power ground and where/how to implement both correctly to reduce noise. Also, I don't believe my apartment has a true ground (most outlets are 2 prong and I think most of those that are three don't have the ground prong connected to anything), so maybe that is part of the problem.

:?:
:?
Thanks.

 

[mhartman]

Good question Spica. I am also interested in seeing how people are grounding things.

Mike

 

[Greg]

Go back and re-read the parts that talk about taking the SW 5V from the R1/C1 juntion. It's very important. Otherwise, you'll be loading the 48V when you start switching things on. I'm at work and cannot explain entirely at the moment.

Not sure about your negative rail problem.

 

[mhartman]

Thanks Greg. I'll look at the thread more closely. Of course (murphy's law), the negative rail problem is what is really keeping me from trying things out. I'm thinking that the voltage regulator may be bad on my negative rail. My reasoning is that I switched all parts, 1 at a time, from the + rail to the - rail and the + rail kept on working pefectly. The only part that I couldn't switch was the regulator. Also, I am getting the same amount of voltage going into the regulator on both rails. So, I'm waiting on a new one to see if it does the trick. Thanks again.