Holger

The reawakening of a beautiful old lady...(API 312)
« on: May 15, 2007, 05:56:54 PM »
This is my version of a late 1970 API 312 PreAmp.
I like the old Altec design so...





I bought an API 312 MicPre from David Kulka.
The 312 schematic told me that there's a dedicated VU meter output. I had an old Altec meter panel in my storage so I decided to use the meter panel and a 2 HU case I once bought from Purusha to house the preamp because it perfectly fits with the meter panel. The meter panel only consisted of the VU meter and the switch.
It took me a while to bring the switch back to life. All in all I spend some 750$ for the parts, but it's worth every buck.
I used Joe Malone's wonderful GoBetween, DI  and 3 rail power supply PCB to finish the preamp. Thanks Joe.
It's one of the best PreAmps I ever used... It's quite, has a wonderful spectral balance and  less pop/plop noises than other MicPre's... I wonder why... :grin:


idylldon

The reawakening of a beautiful old lady...(API 312)
« Reply #1 on: May 15, 2007, 06:09:55 PM »
Very nice work, Holger.  I, too, am a fairly recent convert to the API 312 and I can't believe I went so long in my studio without having them around.  Wouldn't mind adding another pair.

Cheers,
--
Don

3nity

The reawakening of a beautiful old lady...(API 312)
« Reply #2 on: May 15, 2007, 07:13:41 PM »
Woooaaa that's really cool, same old pres...new faces.....like it!!
Altough i found it to be a little expensive! maybe cuz i build 2 for almost 450$..

Anyways worth the expense!!
Life is a path, death the destination.

Holger

The reawakening of a beautiful old lady...(API 312)
« Reply #3 on: May 15, 2007, 07:44:13 PM »
Quote from: "3nity"
Woooaaa that's really cool, same old pres...new faces.....like it!!
Altough i found it to be a little expensive! maybe cuz i build 2 for almost 450$..

Anyways worth the expense!!

See, it's the fair market price you have to pay for the components in these days... David Kulka gave me some further information about the card I've racked so far. I am quite happy. It was worth the effort.

Stagefright13

The reawakening of a beautiful old lady...(API 312)
« Reply #4 on: May 15, 2007, 09:49:54 PM »
Wow congratulations! Very nicely done! Bet she sounds great.

I love api's they just sound cool. I have 4 Eisen API's and 2 more on the way. :)

John
Amateur experimenter

bernbrue

The reawakening of a beautiful old lady...(API 312)
« Reply #5 on: May 16, 2007, 09:32:24 AM »
Hi Holger,
thats a real beauty. Very nice work. I always stated that elderly ladies were much more charming than younger ones.  :wink:
Weiter so!!
regards
Bernd

[silent:arts]

The reawakening of a beautiful old lady...(API 312)
« Reply #6 on: May 16, 2007, 10:41:45 AM »
:shock:
Very nice and clean work :thumb:  :thumb:  :thumb:

reminds me that I still have to rack another 312 I bought from David ...

AnalogPackrat

The reawakening of a beautiful old lady...(API 312)
« Reply #7 on: May 16, 2007, 11:41:20 AM »
Love that look.   :thumb:

A P
If it is to be, it is up to me.

Holger

The reawakening of a beautiful old lady...(API 312)
« Reply #8 on: May 17, 2007, 11:04:44 AM »
Thanks to all. This encourages me to develop more old fashion design ideas.

Holger

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #9 on: June 11, 2011, 11:56:57 AM »
Old thread but I recently did some improvements here.

I removed the original Altec meter switch and replaced it with a Lorlin to switch two different sources to the
now added JLM meter buffer.  I furthermore added an input and output XLR.

The output transformer has two secondaries. The first goes straight to the main output XLR. The other goes to the second
male XLR and is parallel wired to the Lorlin. One can use this signal for additional monitoring.

The second input is wired directly to the Lorlin. I can use the meter now for the MicPre itself, additionally I can meter the second input.
The meter can also be switched off.

Little investment, more functionality. Still cool looking  :)






Re: The reawakening of a beautiful old lady...(API 312)
« Reply #10 on: June 11, 2011, 12:53:17 PM »
Nice.

I did a rack of 6 of these...with original components. They have a neat sound. I'm not sure which input you have, but mine have the 2622's. I find mine to have a soft kind of edge but give good transients.

Edit: Oh.. The input is right there! :) I didn't see the mod #. The Jensen...maybe slightly brighter than mine...
« Last Edit: June 11, 2011, 01:53:56 PM by desol »

reqaudio

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #11 on: June 11, 2011, 02:21:34 PM »


Nicely done - very clean and neat.

...and roomy, the Cadillac of API 312s!

Ayman59

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #12 on: May 17, 2013, 06:53:39 PM »
Hi Holger,

I would like to know what is the pot value and type you used for this project? I do have an api card and want to tease it with a U87 clone I made  :)

Cheers,
Jérôme

Holger

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #13 on: May 19, 2013, 08:34:13 AM »
I can't remember exactly, I think it was an 10k. I need to open it and look.

ruairioflaherty

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #14 on: May 19, 2013, 11:46:42 AM »
Hi Holger,

I would like to know what is the pot value and type you used for this project? I do have an api card and want to tease it with a U87 clone I made  :)

Cheers,
Jérôme

From memory 22k or 25k rev log is the norm for a 312 circuit.

weiss

Re: The reawakening of a beautiful old lady...(API 312)
« Reply #15 on: March 09, 2015, 07:59:53 PM »
what a clean build! awesome ;)


 

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