API 312 Thread!

[MikoKensington]

You are most definately a bad-ass.

 

[Zee1usa]

Nice Pics ! That is a wicked looking box. I cant wait to hear mine.. I am almost finished! Thanks to you.

Z

:thumb:

 

[Viitalahde]

Damn Fabio, nice looking stuff! :thumb:

 

[smallbutfine]

Wow.
Very cool design, Fabio.
:thumb: :thumb: :thumb:

 

[colonelmot]

Hey All

Some dumb questions

Where can I get the a PCB mount grayhill switch or subsitute for my API 312 - I'm in Australia - Farnell only seems to stock non PCB mount ones

Where can I get the c&k switches (or subsitute) listed on baumans partlist?

Does the JLM input transformer work in this preamp? what about his 990 Opamps?

Thanks

Tom

 

[Greg]

Fabio:

:shock: It's about time you got those damn things finished !!! :green:

Nice work !!! :thumb:

 

[AnalogPackrat]

Sweet! Love that retro brushed aluminum panel. :thumb:

A P

 

[Bauman]

Thanks guys!! It was hard work on the mechanicals, first time to me. It is good to be back on the soldering iron and finishing this micpres... hope to jump in another thing before Christmas and then to get a very necessary vacations on January when I will meet
Dan in Argentina to check his U47 (can't help it, even in vacations!!! haha)

:guinness: :guinness: :guinness: :guinness:
many cheers!!

Fabio

 

[laitue5]

Great looking box!

By the way I worked on my 312 too?
But I have a lot of more work before plug it on AC.
:green:

I think I found answers to the questions I asked here:
First version my ?rotary project? for Fabio?s 312 board

This is what I draw for using a rotary to switch from these values:

• 150 Ω mic input (Cinemag 75101APC)
• 600 Ω mic input (Cinemag 75101APC)
• line input
• Hi-Z input

I learned a lot of things in this little ?sub-project? :grin: Thanx all!
I hope I made no mistakes and maybe it could help someone here.
What do you think about the schemo?

One question is remaining:
Do you think that I can use a level trim and a rotary gain selector at the same time as in my schemo?

 

[laitue5]

Line In come into the Cinemag? Do I have to wire the Cinemag for 150 Ω or 600 Ω on primary for line operation?

 

[laitue5]

Since line in signal need to go to input transformer, I corrected the schemo:

Am I right? :green:

 

[kdawg]

A note on the Grayhill rotary switches... I just called Grayhill and ordered two of them here in the US (1-708-354-1040). They said they were in stock and $16 a piece! So funny, I never thought of just calling the manufacturer before... http://www.grayhill.com - you can' t order them online though there.

-kdawg[/url]

 

[laitue5]

Great! I?ll do this if I need more.

 

[kdawg]

I have the Cinemag CMOQ-2S for output - but I'm a little unclear on the wiring. Is it like: (excuse my ASCII :grin: )

IN 1---\ || /-- OUT 1
| || |
| || |
/--/ || \-- OUT 2
| ||
\--\ || /-- OUT 1
| || |
| || |
IN 2---/ || \-- OUT 2

or do I parallel the inputs... or do I serial the outputs? Thanks

-kdawg

 

[laitue5]

Sorry, I can?t understand this ASCII schemo. Could you try drawing a bitmap ?

 

[kdawg]

OOps.. sorry it was 3AM, didn't realize that looked so bad.

Well here's the cinemag colors... I just don't know if I'm supposed to tie the primaries together or what...

-kdawg

 

[Svart]

Hey Fabio, 100pf from in- to out fixed the noise issue!

thanks!

this thing rocks! now i have to get the 2520s working.

 

[kdawg]

Help - my toroid is cooking! I am using Fabio's PSU312 with 2 R312 rev 3 boards. With no load, I was able to get +/- 15V, ~42V, and +5V. With load, voltages are still stable, but I hear the toroid actually starting to sizzle.

For R1/R2, I'm using 10 ohm 5W.
For R10 I'm using 450 ohm 5W

Toroid is a Amveco 62075 2x22V / 35VA. 120 volt setup. Green to VAC1, Red and Brown to center, Blue to VAC2.

I saw something about lifting R10 that is on the other side that goes to LM7805 and running it to + side of C1 - do I need to do that?

For the few seconds that I can turn them on, at least the preamps are passing audio! So close... thanks

-kdawg

 

[Svart]

??? :shock:

it should not be cooking at all. You need to check for shorts! 35va should be plently without getting hot. I am using 50va and it's cold to the touch.

check your caps and make sure there are no 'lytics backwards. that's the first thing that comes to mind when you say that everything works but the toroid is getting hot..

remember to start at the PSU and work out towards the other parts.

 

[CJ]

Sorry for the OT, gonna ship these away so...not enough here for a thread, just a pic of an API output that Soundguy wanted in a "Plexi" motiff, and another Neve output, this time with flying leads, gapped with 0.001 instead of 0.002 for better inductance, and also with the plexi look and some kind of weird bird on it. :shock:

did anybody notice the girls dreadlocks?