Two Box server with linear power supply

[Aryoh]

This is my attempt to create a music server with external linear power supply. It will be a two-box solution but of a slightly more modest scale as far as the processor is concerned.To begin with, some photos of the power supply.

 

 

[Aryoh]

Few photos of the actual music server. At the moment he will replace my 2011 mac mini, ant in the future i plan to use him as a NAA end point. This is Supermicro  motherboard with Xeon E3 1271 processor,  32GB memory and Intel XA520-SR fiber optic card. 

Chassis is HDPlex 2nd Gen H5, and i also use 400W dc-atx converter.

[Aryoh]

Power supply case with switch and output connectors. I use balanced EI transformer, Cree schottky diodes with snubber capacitors and a LC filter with 200000 mF capacitance that will feed HDPlex DC-ATX converter. Another two transformers are for 5 and 12V DC.

[Aryoh]

12 hours ago, Gavin1977 said:

Great posts - would you be able to provide a schematic of your power supply design / components used?

 

I would like to build something similar.

Thank you Gavin1977, i would  be happy to give you a parts list, schematic is simple, it is classic choke linear power supply with large capacitor bank and some extra Mundorf filter capacitors.Idon't know if i'm going to break the forum rules if i post links to manufacturers of some specific components so i can send it to you via PM.

[Aryoh]

13 hours ago, Gavin1977 said:

Great posts - would you be able to provide a schematic of your power supply design / components used?

 

I would like to build something similar.

I use custom made EI transformer with extra copper shield, it is balanced design with 2x10V secundary voltage so i could use 20V imput to a bridge rectifier. Choke is high current Hammond 10A - 10mH , and for bridge i use 6 Nippon Chemi-Con 33000 mF/ 63V capacitors.

I also use Cree Silicon Carbide Schottky Diode C3D16065, and some aluminium polymer capacitors before choke.

[Aryoh]

7 minutes ago, Gavin1977 said:

How is the heat production?

 

You use what looks like some off the shelf PCB's, what's the source?

https://sjostromaudio.com/pages/index.php/hifi-projects/138-rfb03-the-high-current-ultra-fast-rectifier-bridge

[Aryoh]

58 minutes ago, nickquick said:

Hi,

That is a very nice looking build.

 

I am a few years into developing a linear power setup pcbs upwards. Your linears look like Sigma 11 type units, is that right ?

 

If I might offer some thoughts based on experience here which 200,000uf is a LOT on the input of the HDPLEX. Here with a very similar design I am finding that as little as 15,000 after the bridge and 12,000uf after the linear supply feeding into the 400w hdplex is where the sweet spot lies (low esr caps in both locations). Too much capacitance and the  sound gets very solid / slow and dynamics and detail really suffer. Feeding the HDPLEX for good SQ seems to be as much about speed and transient response as it is about ripple performance.

 

The HDPLEX 400W IMHO is an amazing piece of kit, its hard to credit the level of performance available from it if its fed with a really well optimised linear supply. If you havn't already voiced the setup with different levels of capacitance I would at least give it one try tuning this can be  it can be night and day in terms of SQ.

 

Another point you might want to consider. I can see that your HDPLEX is a V2.0x but it may be worth checking exactly which version. HDPLEX recently bought out v2.01 of their 400W DC ATX. I was frankly shocked at the difference in sound quality compared to the earlier v2.00 and have been poking around at board level of  the units to work out what is driving the change to SQ. As the component cost of building such a nice linear supply is pretty high its probably a good investment of $95 to get the 2.01 version if you don't already have it.  

 

It will be nice to hear how it all works out for SQ.

 

 

Hi, nickquick

Thank you for the comment, my LPS for SSD and 12V reserve are based on the Sigma 11 with few modification, I try to use the highest quality components to get the best possible result, but the final result will be seen when everything is put together.

As far as capacitors are concerned, choke plays a big role, i have seen some fantastic results with a 3 times larger bank of capacitors in the LC combination.

 At the moment I'm trying to connect everything into a whole and I'll try fine tuning later so another HDPlex 400 is in the future  

The plan is to assemble another server with a stronger processor for HQPlayer , then I would use this one as NAA, so I will need another power supply, in that one i will try some other LC combination  

When it's all over I'll do my best to share the sound quality information  

 

 

[Aryoh]

31 minutes ago, nickquick said:

I looked again at the pictures of your supply in its chassis. 

 

For my comments on capacitance values to apply I had assumed that the HDPLEX was being supplied by one of the s11 modules or another linear supply circuit that is not visible.

 

If there is no linear regulation in line with the HDPLEX then the cap values are not going to apply well. What are you using to in the design to supply the HDPLEX ? 

 

 

I assumed you were thinking of a combination with Sigma, but my main power supply uses HDPlex as a voltage regulator, which it actually does given that it has a variable input voltage of 16-30V.

 

[Aryoh]

4 hours ago, Dev said:

 

@Aryoh Does the heat pipes clear the DRAM ? Given the spec of 1.26" clearance I though it could barely make it even with a low profile RAM. I was contemplating the HDplex H5 chassis in my build as well but wasn't sure of it.

 

 

Yes, they are about 2-3mm above DRAM that i use.

[Aryoh]

11 hours ago, sandyk said:

Why are there "snubbers" across the Cree  Schottky Diodes ?

 I use the Cree C3D06060A in my Class A amplifier's dual PSUs, but without snubbers.

 You shouldn't need to use them at that location as our own John Swenson shows here in his +5V Linear PSU with a choke input filter

Yes, there are different approaches to this design with schottky diodes but since these are diodes for higher currents I opted for snubbers:

[Aryoh]

Here are a few more photos, power supply is complete, I inserted RFI filtering,  now it's time to complete the server.

[Aryoh]

Today i also received an SSD, Intel MLC, this would be for OS.  On the back of the HDPlex I inserted the power connectors, I still have to mount the 5V connectors. I decided to modify the CPU heatsink, I will make longer copper tubes so I can use the heatsink on the other side of the case as well. I will use acetone as the cooling medium in heat pipes. 

[Aryoh]

Various Molex connectors and housings came from the Mouser. I have not yet decided what kind of conductors I will use for ATX cables, Mundorf and Neotech are a bit too expensive for the diameter of the conductors I need, but Jantzen proved to be very good for me

[Aryoh]

4 minutes ago, matthias said:

@Aryoh

 

Really nice work 🙂

 

BTW, the rack for your gear is also very nice with the stainless steel feet.

 

What is it?

 

Thanks

 

Matt

thank you, it is a rack made here in Croatia, it is completely made of stainless steel.  The shelves are from 40 mm plywood, them i made.

[Aryoh]

10 hours ago, matthias said:

 

Do you have a link?

Is it possible to buy it?

 

Thanks

 

Matt

I can send you a link but I don't think they produce them anymore. 

https://robertoshop.hr/police/

[Aryoh]

I managed to bend the copper pipes, now there is still shortening to measure, filling with fluid and closing the ends