BAE PSU and 2 racks

[Geoff_T]

Originally Posted by a.beck

Mine does this also. (sorry to continue the hijack)

I emailed BAE about this and also running 2 racks from the one PSU, and there was a bit of back and forth, but once they found out I bought mine second hand and not from them, they didn't reply again.

Hi

This is a never ending tale...

The problem is that the various modules available seem to range from 50mA to over 250mA so it is a lottery what modules are fitted and what the current draw, both normal and start up surge, finishes up as.

So, as I posted before...

Option 1 is pull the heavy draw modules out at start up and push them in when fired up... Not a good suggestion

Option 2 is have a power supply that can handle 11 times 250mA = 2.75 amps times 2 to allow for the surge = around 5 amps... Just for one rack, by the way.

Option 3 is to make the power supply at least 3 amps and slow start.

Even trying to run two racks on one small power supply is asking for problems.

The is no substitute for conservatism with power supplies... They are the most neglected aspect of any amplifier.

My GTQ2 channels take around 100mA and I use a one amp power supply for each motherboard.

When I built racks for eight Neve modules, each drawing around 110mA, I used a five amp power supply.

Posted from my iPhone and back from my month long vacation

[jlaber]

Originally Posted by Geoff_T

Hi

Yes but they don't mention, I presume, the in rush current at start up as any big power rail capacitors charge up.

Posted from my iPhone

Good point. I'll add inrush to my spec. I avoid over-sizing bypass caps for this reason.

[bexarametric]

Someone should just make a really badass power supply so we can make this work. It would be nice to power three or four racks with one power supply. It seems that if you do a slow start and have plenty of headroom, that it wouldn't be a big deal.

Vintech, Chandler and Wunder already use this concept with their products (not the slow start up, but the one power supply for multiple units)

Geoff. How much would it cost to make a power supply that could pull this off? I'm just curious because I don't have the slightest idea. For all I know, it would cost $2,000.

[msquared]

Buzz Audio's stated power reqs:
Elixir - 150mA
Essence - 120mA
Potion - 120mA
Tonic - 120mA

500 Series Products from Buzz Audio

[Geoff_T]

Originally Posted by bexarametric

Someone should just make a really badass power supply so we can make this work. It would be nice to power three or four racks with one power supply. It seems that if you do a slow start and have plenty of headroom, that it wouldn't be a big deal.

Vintech, Chandler and Wunder already use this concept with their products (not the slow start up, but the one power supply for multiple units)

Geoff. How much would it cost to make a power supply that could pull this off? I'm just curious because I don't have the slightest idea. For all I know, it would cost $2,000.

Hi

It would cost peanuts

You could use a LM339 five amp regulator with a capacitor on the adjust pin to create the delay.

The circuit is in the National Semiconductor application notes for those that need to know how.

The mindset that one supply can handle two racks should be dropped.

The currents in the post above may not include the surge current...

Posted from my iPhone

[a.beck]

Originally Posted by Geoff_T

The mindset that one supply can handle two racks should be dropped.

Then BAE should drop the 2nd connector from theirs. If that wasn't on there to begin with, this wouldn't even be in question. Alternatively, they could always, you know, make some documentation available on the subject. Crazy, I know...

[Steve Honest]

just call them, i did , and he told me , that the 2nd hole is suited for the 2 unit rack they do, i think its called the 2 ad or somehitng like that,
makes sense , but i agree they could put it up on there website and let us know what its for.
cheers
steve

[TAVD]

Originally Posted by bexarametric

Someone should just make a really badass power supply so we can make this work. It would be nice to power three or four racks with one power supply. It seems that if you do a slow start and have plenty of headroom, that it wouldn't be a big deal.

Vintech, Chandler and Wunder already use this concept with their products (not the slow start up, but the one power supply for multiple units)

Geoff. How much would it cost to make a power supply that could pull this off? I'm just curious because I don't have the slightest idea. For all I know, it would cost $2,000.

You should look at the 51x psu that's popular with the DIY community. It's intended to power +/- 16 volt and +/- 24 volt rails. With a simple change, you could make the +/- 24 volt rail a second +/- 16 volt rail. They also use the higher current voltage regs that Geoff mentioned in a previous post. That would allow you to run 2 BAE racks from one psu. Two psu will fit in a 2u enclosure.

[Geoff_T]

Originally Posted by bexarametric

Someone should just make a really badass power supply so we can make this work. It would be nice to power three or four racks with one power supply. It seems that if you do a slow start and have plenty of headroom, that it wouldn't be a big deal.

Vintech, Chandler and Wunder already use this concept with their products (not the slow start up, but the one power supply for multiple units)

Geoff. How much would it cost to make a power supply that could pull this off? I'm just curious because I don't have the slightest idea. For all I know, it would cost $2,000.

Hi

A PS... The fact that Vintech, Chandler and Wunder make supplies with two outputs is not really relevent (albeit those with long memories can recall issues some had ) because their's are single channel modules aka Neve style and not an 11 unit 500 series rack.

The order of complication due to variance of current from other manufacturers products is much greater.

[Geoff_T]

Originally Posted by TAVD

You should look at the 51x psu that's popular with the DIY community. It's intended to power +/- 16 volt and +/- 24 volt rails. With a simple change, you could make the +/- 24 volt rail a second +/- 16 volt rail. They also use the higher current voltage regs that Geoff mentioned in a previous post. That would allow you to run 2 BAE racks from one psu. Two psu will fit in a 2u enclosure.

Hi

That one puzzled me if you mean PSU's for the 51 series Neve. That beast was about 7U high and was filled with Kingshill individual PSU's that I believe are no longer made.

So I assume that for rack mounting 51 series channels someone came up with a smaller offering?

[TAVD]

^Nope, I meant 51X. It's an evolved DIY modular system, backward compatible with 500 series. I actually never made a connection to Neve 51 series until you mentioned. I don't know if the name was intended as a nod to Neve or just a coincidence.

[Geoff_T]

Originally Posted by TAVD

^Nope, I meant 51X. It's an evolved DIY modular system, backward compatible with 500 series. I actually never made a connection to Neve 51 series until you mentioned. I don't know if the name was intended as a nod to Neve or just a coincidence.

Hi

Then it's merely a coincidence that the type number matches the Neve console series and the +/-24v (actually 25v) and +/-16v were the same supplies that console needed and have no connection with 500 series racks without the modifications you suggested.

[r.staettler]

so no one is using ONE PSU for TWO racks?

i am wondering if its different with the 6 slot BAE rack/PSU...
does anyone know how much mA the PSU of the 6 slot BAE rack provide?