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View Full Version : Regulated Linear Power Supply for Raspberry Pi + Pi 2



bumpy
01-06-2017, 12:11
£150 inc postage

This power supply does a wonderful job of improving sound from the RPI - power supplies are everything. Have a read up of the reviews on line.

It supplies 5 volts either to an RPI, or without the adaptor, to any device needing 5volts

I bought it from new, it is just over 1 year old and is unmarked.


20442204432044420445


From the manufacturer

MCRU and Longdog Audio have developed a regulated linear power supply based on the multi award winning 2 case design which was reviewed by Hi-Fi Choice magazine and award 5 stars and a recommended badge. Here is a review of the 5V power supply we sent to Hi-Fi Choice.
Our power supplies improve sound quality based on 100's of satisfied customer feedbacks. The raspberry Pi and Pi 2 requires 5V DC to power it, it can be powered by the voltage from a USB socket but this can be noisy, using a fully regulated design will enhance performance and get the very best audio sound from the Pi when used as a music source.
The Pi uses a micro USB socket for power, we supply a DC plug to micro USB adpater cable to connect the linear psu to your Pi.
The design rational from Longdog founder Nick Gorham is below.
When thinking of regulation, it’s worth remembering the Roman god Janus. Who was the god of gateways, and was a two faced god looking in both directions. Likewise a good voltage regulator is required to look in both directions at once. From one direction you have the mains supply, with the ever increasing noise, distortion and random variation that exists on our household mains supply. In the other direction you have the device you are supplying power to. The load will be asking constantly varying current, and the job of the regulator will be to ignore the varying load and to supply a rock steady voltage that ignores the changing load.
To ask a single regulator to perform both tasks means that it can not do either as well as it could. We don’t ask our regulators to be two faced, we split the two functions into two separate regulators and put them both where they can do the best job.
The first regulator is close to the mains supply, its job is to take the incoming mains and convert it into a low(ish) noise DC supply, and to isolate the mess that is our household power lines from what follows. In most power supplies on the market, the output of the first stage would be directly connected to the load device, and that would certainly be an improvement over the supplies that most manufactures provide. But we can do better by adding the other face of Janus to the system.
The second regulator is supplied with a clean low noise supply, and its job is to handle the changing demands of the load. To do that, it needs to be as close to the load as possible. So we remove the second regulator from the main box, and place it close to the load, both electrically and physically, that removes it from the noise and interference of the mains supply, and allows it to spend its time looking towards the load. Typical commercial voltage regulator chips are general purpose devices, but are not quiet enough for the task on hand, so the second regulator uses a bespoke regulator based on a low noise multi stage filtered voltage reference, a low noise error amplifier and a high current low resistance mosfet. To allow it to handle the changing load it also needs to supply current on demand, so all the remaining space in the second regulator is filled with low impedance capacitors to act as a local energy source.
Using the two stages of regulator, we achieve a noise floor equal or better than most battery supplies, and a effective source resistance of the order of 0.02 ohm (and the short cable run to the load avoids increasing this valve by adding copper where its not needed, and the use of a discrete regulator design allows that tiny value to be maintained way above the frequency any audio device operates at.

mikeyb
01-06-2017, 13:39
Ampage?

It's probably 2a but thought I'd ask.

I had one that I sold recently and they do make a good difference​over the usual wallwart supplied with most devices.

bumpy
01-06-2017, 14:44
Ampage?

It's probably 2a but thought I'd ask.

I had one that I sold recently and they do make a good difference​over the usual wallwart supplied with most devices.

I cant find the amperage anywhere on the MCRU Web site, but it says it replaces any Walmart switching power supply. It certainly never got more than mildly warm running the RPI

eksiil
01-06-2017, 16:53
would it not suit a Pi3?

bumpy
02-06-2017, 12:09
would it not suit a Pi3?

I'm sure it will suit the Pi3 but I was just quoting from the MCRU advert.

bumpy
06-06-2017, 16:50
And for those wondering if it comes with a box.

WESTLOWER
06-06-2017, 21:41
Top box that ! Glwts chris

bumpy
09-06-2017, 10:02
Top box that ! Glwts chris

Thanks. Worth the entrance money on its own. :)

bumpy
23-06-2017, 14:12
Now £140 inc postage

bumpy
24-07-2017, 20:08
Xx

struth
24-07-2017, 20:31
Still happily using a powerpack battery for mine. I dont leave mine on so it lasts for an age

GJO
25-07-2017, 07:43
Inappropriate post

bumpy
17-09-2017, 17:24
xxx

bumpy
26-01-2018, 19:22
Forgotten all about this, so thought I would give it a bounce.

bumpy
18-02-2018, 15:32
bumpy

Markiii
18-02-2018, 18:06
I'll take it please fella

bumpy
18-02-2018, 18:55
I'll take it please fella

I see you're local to me Mark. If you want to collect I will knock another fiver off and it's yours for £135. If you want, you can have a little listen to my system which is very different to most.:)

Markiii
18-02-2018, 19:12
I'll be passing you next Friday afternoon if your about?

bumpy
18-02-2018, 19:31
I'll be passing you next Friday afternoon if your about?

Next Friday would be good, and early afternoon even better. I will pm you my address before then.

Cheers Chris