chipss36

Re: Access-312 Build Thread
« Reply #560 on: March 11, 2018, 07:43:28 PM »
Yes it’s the power supply many used , and has a dead link on the first page.

I have the board but zero info on it.
« Last Edit: March 12, 2018, 12:30:16 AM by chipss36 »


Whoops

Re: Access-312 Build Thread
« Reply #561 on: March 12, 2018, 04:52:16 PM »
That PSU is long gone and it was just a sugestion at that time.

Don't worry about it,
you can use any 3 rail PSU.
You need +16V, -16V and +48V for the phantom power

You can buy this one with "extra aux rail" option:

https://pcbgrinder.com/POWER-SUPPLY-PSU-LM317-LM337





chipss36

Re: Access-312 Build Thread
« Reply #562 on: March 12, 2018, 05:56:08 PM »
 Buying another is an option but was not the question asked.
Just saying.
Still looking for documentation on the psunaversal power supply.
Thanks.

bxt403

Access-312 board for API 325 line amplifier (or equivalent)
« Reply #563 on: April 03, 2018, 08:15:39 PM »
I noticed that the Access 312 board can be converted to into a 325 circuit fairly easily (after some component value changes and removing the input transformer). This is useful when you  want a pair to be used for stereo signals (where the gain switch for two modules is a double pole type: one pole per module)

I've cross-referenced with the API 325 manual's "Line or Booster Amplifier" section and it looks like the 325 has "Open" for a 6dB minimum and maximum value of  42dB @ 240 Ohm (for the column that corresponds to the output transformer's wired as two windings in series like it is on the Access 312).  That means (for those who might want to wire a pair of  Access 312s as a pair of 325s for stereo signals and since a double pole 2 throw switch is easier to wire than a 9 to 12 pole one):  12dB = 39K Ohm,  18 dB = 13K Ohm, and 24dB = 5.6 K Ohm). 

The components that change are all the ones from the signal input to the transformer input.  Everything related to the +/- 16 to 20 Volt power input can be left the way it originally is on the Access 312 schematic (although you might want to increase the two 35V electrolytic capacitors to around 50V if you intend on supplying +/-20V to the modules).

 




« Last Edit: April 14, 2018, 09:29:06 PM by bxt403 »

3nity

Re: Access-312 Build Thread
« Reply #564 on: May 26, 2018, 10:36:29 PM »
Bxt403.
In fact I used a 312 PCB stuffed parts like a 325 for a poor man eq gain stage..works perfectly.

Life is a path, death the destination.

Le Roux

Re: Access-312 Build Thread
« Reply #565 on: July 15, 2018, 04:37:33 PM »
Thought I'd add a pic of my 4 channel build

Love this preamp!

3nity

Re: Access-312 Build Thread
« Reply #566 on: July 15, 2018, 10:30:34 PM »
Nice build.
Love the vertical mounting of the boards.
The di is the Bo Hansen?

Cheers.
Life is a path, death the destination.

Le Roux

Re: Access-312 Build Thread
« Reply #567 on: July 16, 2018, 04:08:17 PM »
DI is JLM

Bo Hansen would have been awesome! Totally forgot about that project!


 

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