MOTM

Hi,

My MOTM system has expanded and the non MOTM modules are really power hungry(ZO,
Time Machines,etc...). I also have a MOTM-650.

I have been to Dave's Hot Rod MOTM site to read about upgraded power supplies and
wiring and it's still not clear what the most practical what of going about this is.

I will eventually have around 40 modules divided into 2 homemade cabinets that I would
like to use one power supply for. They will not be just for home use because I plan on
touring with them(states,europe,etc).

I would like to know:

What power supply to use?

The best way to connected the cabinets power-wise? 4 connector Neutrik?

And and any other useful information you may have discovered.

Thanks in advance.

David Scott Stone

If it were me, I'd run a supply in each cabinet. Some redundancy,
especially when touring. Half the load on each, less noise coupling.
Higher reliability since there aren't external cables and connectors.

I slave the AC mains from a single power switch. I run a power supply
in each of my 5 cabinets with the max at 24U or about 16 modules. My
10U of digital modules are in their own cabinet with a dedicated power
supply. Just my opinion. Can't have enough power supplies.

Dave

--- In motm@yahoogroups.com, "earthtodylan2000" <sir_dss@...> wrote:
>
> Hi,
>
> My MOTM system has expanded and the non MOTM modules are really
power hungry(ZO,
> Time Machines,etc...). I also have a MOTM-650.
>
> I have been to Dave's Hot Rod MOTM site to read about upgraded power
supplies and
> wiring and it's still not clear what the most practical what of
going about this is.
>
> I will eventually have around 40 modules divided into 2 homemade
cabinets that I would
> like to use one power supply for. They will not be just for home use
because I plan on
> touring with them(states,europe,etc).
>
> I would like to know:
>
> What power supply to use?
>
> The best way to connected the cabinets power-wise? 4 connector
Neutrik?
>
> And and any other useful information you may have discovered.
>
> Thanks in advance.
>
> David Scott Stone
>

I agree with Dave, use redundant supplies and lots of them, and keep
the digital modules in a separate cabinet with their own power
supply. Although the MOTM-900 power supply suggests how many modules
you can safely power with it, that number goes way down once you
start adding non-MOTM modules and other daughterboard enhancements.

I currently have 6 cabinets, each cabinet has 36U of modules, and
each cabinet has their own MOTM-900 supply. For the past few years
most of my cabinets have had a few empty spaces in them so each power
supply has had to serve about 15-18 modules. But over the past few
months I've been filling up the cabinets and finding, especially
after adding additional daughterboards to many of the modules, that
I'm running the power supplies dry (the non-MOTM modules are the
worst power hogs). Now I'm going to have to disassemble the whole
thing and double-up the power supplies in each cabinet. groan.

>If it were me, I'd run a supply in each cabinet. Some redundancy,
>especially when touring. Half the load on each, less noise coupling.
>Higher reliability since there aren't external cables and connectors.
>
>I slave the AC mains from a single power switch. I run a power supply
>in each of my 5 cabinets with the max at 24U or about 16 modules. My
>10U of digital modules are in their own cabinet with a dedicated power
>supply. Just my opinion. Can't have enough power supplies.
>

On 4/11/07, earthtodylan2000 put forth:

>What power supply to use?

I would recommend a Power One supply. You need to add up the current
requirements of all your modules, then choose a supply that provides
more current than that. Considering inrush current, and that
manufacturers might underestimate the current consumption of their
modules, this is a case where more is more.

>The best way to connected the cabinets power-wise? 4 connector Neutrik?

Larry and I had discussed using 4-connector Neutriks. You might want
to check the archives. Using speakons offers several advantages --
excellent strain relief, designed to carry large voltages and
currents (250V/30A), work well with large gauge wires (up to 10AWG),
and are available in numerous mounting configurations (cable,
chassis, pcb, screw terminal, etc.)

>And and any other useful information you may have discovered.

Although I haven't had any ground issues interconnecting my MOTM with
other gear, it is best to keep the ground paths as equal as possible.
I would recommend using one large power supply, using DC cables of
equal length, and using a star configuration as much as possible. If
you use two power supplies, you might want to connect their grounds
together.

At 10:36 PM 4/10/2007, earthtodylan2000 wrote:

>...
>The best way to connected the cabinets power-wise? 4 connector Neutrik?

If you decide to do this, instead of using one supply per cabinet,
you might take a look at what Synthesizers.com does. There are
"Inter-Cabinet DC Power Cables"
(http://www.synthesizers.com/q101.html) that use 4-pin connectors,
wired as described at http://www.synthesizers.com/technical.html

See also the Q103 DC Power Interface Module
(http://www.synthesizers.com/q101.html).
--
john


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I have 3 cabs each with 48u of modules with one 900 PSU per cab. About
1/3 of the modules are MOTM, 1/3 Oakley and 1/3 misc.

FWIW I found that using CGS PSU delay boards to stop all the modules
powering up at once in each cabinet makes the 900's way more stable.
They can tolerate many more modules.

I probably should calculate the actual current usage per PSU to make
sure it's all safe but i understand the 900's will auto-shutdown if
you milk them too hard.

ac

On 4/11/07, Scott Juskiw <scott@...> wrote:
> I agree with Dave, use redundant supplies and lots of them, and keep
> the digital modules in a separate cabinet with their own power
> supply. Although the MOTM-900 power supply suggests how many modules
> you can safely power with it, that number goes way down once you
> start adding non-MOTM modules and other daughterboard enhancements.
>
> I currently have 6 cabinets, each cabinet has 36U of modules, and
> each cabinet has their own MOTM-900 supply. For the past few years
> most of my cabinets have had a few empty spaces in them so each power
> supply has had to serve about 15-18 modules. But over the past few
> months I've been filling up the cabinets and finding, especially
> after adding additional daughterboards to many of the modules, that
> I'm running the power supplies dry (the non-MOTM modules are the
> worst power hogs). Now I'm going to have to disassemble the whole
> thing and double-up the power supplies in each cabinet. groan.

This is what it says:

"Connectors: 6 pin male circular DIN with metal hood.
Cable: 4 conductor, 24awg stranded.
Maximum Current: 1 amp"

Imho, that is insufficient for what the original poster is doing.
Nor are DIN connectors particularly road-worthy.

Also, using speakons with common electrical cable would cost less money.

On 4/11/07, John Mahoney put forth:

>At 10:36 PM 4/10/2007, earthtodylan2000 wrote:
> >...
> >The best way to connected the cabinets power-wise? 4 connector Neutrik?
>
>If you decide to do this, instead of using one supply per cabinet,
>you might take a look at what Synthesizers.com does. There are
>"Inter-Cabinet DC Power Cables"
>(http://www.synthesizers.com/q101.html) that use 4-pin connectors,
>wired as described at http://www.synthesizers.com/technical.html
>
>See also the Q103 DC Power Interface Module
>(http://www.synthesizers.com/q101.html).

I should add that even with my supplies lightly loaded I had trouble
with them powering up correctly. I ended up designing my own PS
sequencing circuit before Ken did his to solve the problem. I keep an
excel spreadsheet of my current. I have measured all of my modules so
these are representative currents. The first 4 are all 800 mA power
supplies and the last is a 400 mA supply. I was seeing power-on
problems on the 461/448 and 324/231 loads. I do have before and after
photos of the supplies with my delay if people are interested. It
made a big difference in shortening the power up from 40 mS to around
5 mS.

For external loads, such as my keyboard, I use the Tyco CPC Circular
Plastic Connectors which seem to work very reliably. I don't remember
the current rating but I doubt that they would be suitable for an
entire cabinet.

+15 -15
--- ---
568 379
461 448
324 231
334 114
265 251

http://modularsynthesis.com/modules/DJB-Power/djbpower.htm

--- In motm@yahoogroups.com, ac <analoghell@...> wrote:
> FWIW I found that using CGS PSU delay boards to stop all the modules
> powering up at once in each cabinet makes the 900's way more stable.
> They can tolerate many more modules.