'Analog Dinosaur' succumbs to the joys of FBA : enter Raspberry Pi 2/IQ-Audio DAC+!!

[lovejoy]

Looks very cool Marco - I'm thinking I may well go down this route myself. I have a question about how it works though.

As I understand it, the Pi2 has on board regulation which uses switching mode regulators - Are these removed/bypassed, and if not, do they have an effect on what the external PSU is doing?

[Marco]

Hi Richard,

That's probably more a question for Paul. I think that they are by-passed, and Paul's own bespoke regulators in the SR3DR are used instead. Hopefully Paul will come along soon though and answer your question

Glad you like the PSU. It looks great in the flesh and feels reassuringly 'chunky'. It certainly makes the RPi sound more finessed and 'grown up'. It's all about removing noise, as computers are inherently rather noisy buggers (and that's one of the things that can make digital replay sound 'hard').

Remove said noise as much as possible, and that's when the music starts coming through, and the whole sound as a result opens up and becomes more relaxed and 'musical'. It sounds simple, but it's precisely what's wrong with most FBA devices: not enough attention is paid to noise suppression.

The wall-wart switch-mode power supply, which comes with the RPi is pretty decent, but switching to the SR3DR is akin to the effect one would expect from a major amplifier upgrade: just much more subtlety and control, together with significantly increased resolution. It's a complete no-brainer! If you want to turn your RPi into a veritable high-end music streamer, that's how to do it

Marco.

[Marco]

Just to add this if it helps, which I received in a PM from Paul, in reference to 'what's in' the SR3DR:

Regarding the internal components etc. the transformer VA rating is 60VA and the regulator circuit topology is my standard PR3 (positive regulator 3) series regulator circuit as used in the standard SR3 power supply. The main difference is the additional regulator stage, which enhances the performance with regard to supply line rejection and reverse transfer interference rejection back to the mains supply from the Pi digital processing activity. The supply line rejection also applies to any noise and rectification ripple generated by the rectification process prior the regulation stages.

Marco.

[Paul Hynes]

Hi Rich,

The plan is to remove the on board regulator chip and replace it with high performance regulators, preferably on the board, but this will depend on the actual current required by the individual supply rails, as this will dictate the size of regulator module I will have to use. I have some small high-speed regulator modules but space is quite restricted, so they might be better sited next to the Pi motherboard adjacent to the site of the original regulator chip. I will also remove any unnecessary components associated with the regulator chips that might interfere with the workings of the regulator upgrade.

Regards
Paul

[guyb]

Hi Guy,

I would be disinclined to have the mains transformer and rectification in the same enclosure as the Pi as stray field interaction is usually very difficult to deal with in a single enclosure. I usually keep the master supply with transformer and pre-regulation in a separate remote enclosure and then apply local regulation in the signal processing enclosure as close to the load as possible.

Regards
Paul

I thought that may be the case. As I can't find any decent cases for the Pi and I like things looking uniform and matching I thought it, from a purely cosmetic aspect, it might look quite cool. I guess if I bought a PSU from you maybe I could buy an empty case that I could somehow mod to fit the Pi (assuming that you would of course)

Based on your above comments, are you planning on offering a customised Pi that has been modified for better use with your PSUs or are you just thinking of modding your own?

Guy

[Paul Hynes]

Hi Guy,

I might be able to arrange something along the lines of a machined case if there is enough interest. This would not be viable as a one off because of the tooling set up charges.

If the Pi regulator upgrade is as successful as the SL1210 internal regulator upgrades I will be offering a modified Pi that has the 2nd level of regulation and the SR3 will be the master external power supply.

Regards
Paul

[badsoden]

Hi Guy,

I might be able to arrange something along the lines of a machined case if there is enough interest. This would not be viable as a one off because of the tooling set up charges.

If the Pi regulator upgrade is as successful as the SL1210 internal regulator upgrades I will be offering a modified Pi that has the 2nd level of regulation and the SR3 will be the master external power supply.

Regards
Paul

Hi Paul,

Tried sending you a PM but your inbox is full. I would be very interested in a machined case for my Raspberry PI and DAC board. Let me know if you go ahead and any more details if you get that far.

Thanks

[Paul Hynes]

Hi Chris,

I have cleared some space in my in box.

Ok, you and Guy have started the ball rolling for interest assessment for a machined case.

Is anyone else interested? If so please state your interest on my PHD thread at :-

http://theartofsound.net/forum/showt...528#post653528

This will avoid cluttering up the main Pi thread here.

Regards
Paul

[guyb]

Join the queues and bide your time. All out of stock vendors will get their new supplies at much the same time. Shortest queue is the only option or look for a S/H one.

Managed to get one

Really interested to see how it compares to using my Pi with my DAC!

Do you guys think it will be better - everyone seems to think it is great.

I will be using it with my Chord Chameleon Silver Plus interconnects - I hope these will match the DAC+ well and I don't have the problems some have had with interconnects.

[montesquieu]

Managed to get one

Really interested to see how it compares to using my Pi with my DAC!

Do you guys think it will be better - everyone seems to think it is great.

I will be using it with my Chord Chameleon Silver Plus interconnects - I hope these will match the DAC+ well and I don't have the problems some have had with interconnects.

Rather depends on your DAC I suspect!