19" 9volt rack mount unit

[Trunker]

I am in the process of tidying up our front of house racks (I am fed up with the cable spaghetti) and I am looking for a unit that will feed 8 Alesis/any 9volt units without having to use any of the bulky 'wall-worts' that power them at the moment. Can anyone point me in the right direction please. I cannot find quite what I need atm. Thank You.

[DrV]

I am in the process of tidying up our front of house racks (I am fed up with the cable spaghetti) and I am looking for a unit that will feed 8 Alesis/any 9volt units without having to use any of the bulky 'wall-worts' that power them at the moment. Can anyone point me in the right direction please. I cannot find quite what I need atm. Thank You.

 

Sounds like a nice little DIY project - 1u chassis or open shelf containing a 9volt laptop style PSU (class II type with floating outputs), a box with a DC input connector, 8 flying leads and 8 resettable fuses (polyfuses) on a bit of Veroboard...

 

Dave

[boswell]

I'm trying to do the same thing but want to keep away from switch mode laptop types due to noise etc. It's to power a load of Mic receivers.

Looking for a linear 9v 5A regulated supply, tried RS,CPC and a google search, not found any so far under £100,

otherwise its build one!

[DrV]

I'm trying to do the same thing but want to keep away from switch mode laptop types due to noise etc. It's to power a load of Mic receivers.

Looking for a linear 9v 5A regulated supply, tried RS,CPC and a google search, not found any so far under £100,

otherwise its build one!

Point taken although a class II type inside an earthed metal box with an RFI filter on the output leads should be pretty quiet. There's plenty of audio kit around using switch mode PSUs on low level signals.

 

A compromise if you are building one yourself would be to use something like a bank of LM2675-ADJ step down regulators. They switch at secondary voltage so don't radiate anything much, the input can be anywhere between about 12 and 40v so you don't need a huge smoothing cap for the reservoir and they are amazingly efficient and have their own thermal protection. Thinks - must apply for a sales job at National Semiconductor sometime :)

 

Dave

[Lamplighter]

I have been using 2 switch mode supplies to power my radio racks for the last 3 years with no noise problems. One is a 12 volt 10 amp unit supplying the receivers, UHF and VHF, spread over 3 racks. The other is 24 volt 2 amps for the UHF aerial distribution amplifiers. This keeps the weight of the racks low enough for me to transport them without assistance. Each receiver is fed via a suitable polyswitch (PTC) to prevent total shutdown if one receiver decided to short the supply. The 12 volt unit would happily adjust for 9 volts.

Brian

[ablett]

This is the guy to talk to...

 

www.orchid-electronics.co.uk or 01392 438844

His name is John. He can make you anything for this industry! He is very reasonably priced and his quality of work is outstanding.

 

Give him a call.

[J Pearce]

Would a guitar pedal power pack do the job? Mount it on a 3U blanking plate if it needs to be rack mounted.

[Quincy]

I have used these guys a couple of times, they do just about everything!

 

http://www.allpsu.co.uk/

 

Andrew

[jamesperrett]

I am looking for a unit that will feed 8 Alesis/any 9volt units without having to use any of the bulky 'wall-worts' that power them at the moment.

 

Many of the Alesis units that I've used are AC rather than DC. Feeding them 9V DC may not blow them up but it may not be sufficient to power some parts of the unit as a 9V AC supply will translate to just over 12V after rectification and smoothing. It is also possible to derive bi-polar supplies from AC but not from DC.

 

I seem to remember that Studiospares used to sell a 9V supply with multiple outputs but you may well need a custom PSU if the Alesis units are AC input.

 

James.

[Alec]

Many of the Alesis units that I've used are AC rather than DC. Feeding them 9V DC may not blow them up but it may not be sufficient to power some parts of the unit as a 9V AC supply will translate to just over 12V after rectification and smoothing. It is also possible to derive bi-polar supplies from AC but not from DC.

 

Yes, they're a complete pain, aren't they. Some old Lexicon units use the same.

 

At least now we seem to be settling on 12V DC for most items, which makes it much easier to mix & match adapters.

 

Can't believe how at home, my family believe that: if an adapter fits, it's fine to use it. Have found things with adapters supplying 3 times the voltage before. However many times I chastise them for this, they still are incapable of reading the numbers...

[Trunker]

Thanks for all your replies. I haven't got the rack in front of me atm, so unsure of if it is AC or DC. The unit is to power 4 Alesis 3630 Compressor/Limiter/Gate units, 2 Midiverb 4 units, Microverb 3 unit and A N OTHER. There will also be at least one Graphic EQ and an Aural Exciter in there, so I am wondering if I should just put an 19" 8 way 13a plug-board in there instead because the Graphics take 13-IEC leads. Maybe the easiest route looking at it.........

[timtheenchanteruk]

can tell you the midiverb and microverb are 9V AC, got one of each infront of me. would think the rest of the alesis offering are also AC.

[Robin Pratt]

The 3630 compressors are certainly AC, and my experience of trying to run several from a single power unit was lots and lots of hum. In the end went for a 1U box with multiple small torroidal transformes each with 2 isolated output windings and that worked perfectly.

[Trunker]

The 3630 compressors are certainly AC, and my experience of trying to run several from a single power unit was lots and lots of hum. In the end went for a 1U box with multiple small torroidal transformes each with 2 isolated output windings and that worked perfectly.

 

That don't sound like what I want :) Lots of hum on a recording or live sound job = less and less work. I am beginning to disown this idea and go down the 13 amp round mount socket route, even though I am still going to have cable management to do.

[djmatthill]

Heres a thought.

 

What about a 2 or 3U rack box (like the type that rack mount PCs use)

 

Screw two 4way mains sockets and use the existing "wall wort" PSU`S you have.

 

Now I would fit a couple of fans and drill plenty of air holes in the top and rear - Unles your rackbox has air vents and fans included ....

 

Then mount a IEC socket on the back and 8 DC style sockets , or some other multi pin socket (small EDAC)

 

Then maybe a Illumiated rocker switch on the front panel ????

 

Search EBAY for all the above.... cheao cheap cheap ..

 

Maybe even buy an old rackmount PC that has died and canablise it ????

 

 

 

 

COST .. £50ish