Whoops

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #160 on: August 19, 2020, 09:03:49 PM »
I have basically put the black to where it says AC on board, put the yellow to where it says AC on board, then i combined the red and orange and put them both to CT & CT.

Should be good, both CT points should connect to each other.
Check it out measure continuity between those 2 points.
Also reference with the schematic


Whoops

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #161 on: August 19, 2020, 09:04:56 PM »
This will also work



TillM

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #162 on: August 20, 2020, 02:51:49 AM »
Too much power?

It's 700mA per each primary. So it's good to power 4x 312 Mic preamps plus phantom power and still have some good safety margin.

No I mean I would take a transformer with 15vac at the secondaries.
But that’s just my choice.
« Last Edit: August 20, 2020, 03:11:17 AM by TillM »

Whoops

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #163 on: August 20, 2020, 03:06:27 AM »
No I mean I would you a transformer with 15vac at the primaries.
But that’s just my choice.

Oh yeah, the 18VAC will rectify to 25,4VDC
A little more heat and wasted energy
« Last Edit: October 26, 2020, 09:32:12 PM by Whoops »

Whoops

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #164 on: August 20, 2020, 03:11:56 AM »
When you center tap them, you get 36vac.
So you have to put them in parallel.
So that you just connect the AC on your PCB.

Sorry TillM this is not correct, the CT is the 0V reference and connected to ground. So it's 18VAV on each side of the secondaries with opposite polarities

TillM

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #165 on: August 20, 2020, 08:19:53 AM »
Sorry TillM this is not correct, the CT is the 0V reference and connected to ground. So it's 18VAV on each side of the secondaries with opposite polarities

Thank you for your explanation.

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #166 on: August 20, 2020, 06:50:00 PM »
Sorry TillM this is not correct, the CT is the 0V reference and connected to ground. So it's 18VAV on each side of the secondaries with opposite polarities

Thank you so much for your in-depth explanation and diagram, This has been so helpful and very much appreciated!! Both you and Tiim.


JW

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #167 on: October 26, 2020, 12:58:11 PM »
Howdy folks,

I have a couple CAPI ACA boards that can fit 4 opamps each for a total of 8. I don't see why I couldn't put 8 in a single rack enclosure with the the ML12 power supply?

Couple questions though. Is there a stated maximum amperage for the ML12 supply? Or is it just up to the LM337/317 pair? I think a couple people have built 8 channel units, so that's why I'm here. On the 2520 data sheet I remember around 80mA current draw at absolute worst case scenario. If we over estimate for the possibility of (even more dramatic current drawing DOA's?) Let's say 120mA per channel X 8 = 960mA. A 1.2A PSU would cover just about any scenario I imagine.
 
Is there a torroidal power transformer one would recommend for this kind of power that could fit in a 1RU chassis? And should I be looking at changing the 337/317 transistors for something slightly higher?


3nity

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #168 on: November 15, 2020, 03:35:07 PM »
 Hello good people.
I'm helping a friend completing this project but no more schematics..
I'd like to find a pin out for the fet DI2. 5 pin connector..please let me know if you have it please e mail me at mayaaudio AT gmail.com please.

Thanks
Life is a path, death the destination.

TillM

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #169 on: November 16, 2020, 11:14:20 AM »
I will take a look on my HDD when I’m back home.
I am sure I still have the manual.


3nity

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #170 on: November 16, 2020, 06:44:25 PM »
Thanks
Life is a path, death the destination.

Whoops

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #171 on: November 16, 2020, 09:58:35 PM »
Hello good people.
I'm helping a friend completing this project but no more schematics..
I'd like to find a pin out for the fet DI2. 5 pin connector..please let me know if you have it please e mail me at mayaaudio AT gmail.com please.

Thanks

Hi Jorge,
if you use wayback machine website and post the dead links there you can access the files

https://web.archive.org/web/20160322190325/http://www.whistlerockaudio.com/cart/documents/ML12/ML12%20v3.0%20-%20Schematic.pdf

https://web.archive.org/web/20160218185143/http://www.whistlerockaudio.com/cart/documents/ML12/ML12%20v3.0%20-%20PCB%20Manual.pdf

https://web.archive.org/web/20160322215846/http://www.whistlerockaudio.com/cart/documents/ML12/ML12%20v3.0%20-%20Mechanicals%20(PCB%203.1).pdf


Best regards

3nity

Re: Whistle Rock Audio ML12 preamp BUILD/HELP thread!
« Reply #172 on: November 18, 2020, 08:04:01 PM »
Thank you whoops!
Life is a path, death the destination.