Soekris' DAC implementations

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Thank you Rudy,

I already use it while not understood all (self lake of knowledge). But can this soft take into acount some exceptions : like my only 11.3 VAC at secondaries output with my 9 V R-core ? I mean here it's less than x 1.41 !

Have to say than after I don't understand all the curves ! :eek: while able to read the results with numbers....

Good idea, will re test it ! must be somewhere at home on a XP pc ! If it shows the VDC & AC peak to peak it will be enough as the R-core is below a torroid in relation to the results: my understanding is this design was maid for torroids.
 
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Thank you Rudy,

I already use it while not understood all (self lake of knowledge). But can this soft take into acount some exceptions : like my only 11.3 VAC at secondaries output with my 9 V R-core ? I mean here it's less than x 1.41 !

Have to say than after I don't understand all the curves ! :eek: while able to read the results with numbers....

Good idea, will re test it ! must be somewhere at home on a XP pc ! If it shows the VDC & AC peak to peak it will be enough as the R-core is below a torroid in relation to the results: my understanding is this design was maid for torroids.

The sqrt 2 multiplier to get peak voltage from RMS voltage is the same no matter what trafo. I personally prefer toroids as they're usually smaller, with better load regulation, with significant smaller inductive field and less noisy. But you can use any trafo meeting the specs minimum spec.
 
Ah, this time I can answer (I hope !) : 10 VA is what is absorbed by the traffo not by load.

Dangerous for the traffo if the load ask more than the traffo can give only.

Here this is not the case as it seems the load needs 5 W so 5VA or maybe better to say 7.5 VA peak to peak (technicians will rectify if I'm wrong) ?

So with more than 7.5 VA you are good. Some says than traffo between 30 VA and 50 VA are the quietest...

There are some direct links in the Vendor thread for torroids in the official thread.
 
:( Harghhh !

I was believing it was what the seconadry which is "absorbing" in continue this VA capacity due to its winding while the load can takes its own need into this limitation !

:sad: Ok, i come back to lego and saucepans this time ! This night I melt all my devices to makes a frying pan and come back to the kitchen where the place of a french is ! :snoopy:
 
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To reduce the risk for some DIYers, probably Sokries could recommend one or two "official" third party trafos for this DAC on the front page?

There are two multicomp transformers sold by Newark/Farnell/Element14 that have been suggested in the Vendor thread.

2x7AC 7VA (cheaper and 20 in stock)
MCFM70/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 7VA | element14 Australia

2x7AC 5VA (more expensive and currently out of stock)
MCFM50/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 5VA | element14 Australia

The links are to the Australian website but it's easy enough to change location using "Change Country" at the top right of the page.

The 2x7AC 5VA is also available from a UK based seller on eBay (more than 10 in stock)
MCFM50 07 Multicomp Mini Toroidal 5VA 2X 7V | eBay
 
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More alternatives...

Nuvotem - Talema
Open toroids sold by Digikey. RS Electronics (not Rad*o Sh*ck) sell the PCB mount versions.

Open toroid:
62020 - 2x7AC 5VA - http://www.digikey.com/product-detail/en/62020/1295-1108-ND/3881389
62030 - 2x7AC 7VA - http://www.digikey.com/product-detail/en/62030/1295-1059-ND/3881371
62040 - 2x7AC 10VA - http://www.digikey.com/product-detail/en/62040/1295-1058-ND/3881370

Encapsulated PCB mount:
70020K 2x7AC 5VA
70030K 2x7AC 7VA
70040K 2 x7AC 10VA

Thanks. That's certainly a useful piece of info.
 
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The footprint for the XLR jacks matches Neutrik NC3M**H jacks:

A- Series: "The `State of the Art` receptacle. Round plastic body XLR pcb mount panel connector. These have the smallest size and highest packing density (23mm between centres). New designed tulip type female contact on 3 pin versions and fork type on 4 and 5 pole female connectors with hard gold plating and polished contact areas."

NC3MAH

----

AA-Series: "New most cost-effective round plastic body XLR PCB mount panel connector. Front panel cutout and pcb layout 100% compatible to A series. New "tulip" type contact design with high contact pressure for highest durability."

NC3MAAH

----

B-Series: "Same as A series with exception of a metal mounting flange featuring continuous circumferential ground contact to chassis for best EMC practice. Available as 3 pole female and male connectors including a special version with 8 ground contacts (-E) for best conductivity of mating shell to ground."

NC3MBH
NC3MBH-B
NC3MBH-E

----

You can always wire from the board to panel mount XLR if you prefer.
 
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The uk.farnell.com website indicates that farnell/element14 are expecting 25 x MCFM50/07 to be available for delivery on the 25-Jan-2015. Supplier lead time is listed as 13 weeks.

I guess eBay option may be safer if you're in a hurry.

I was surprised too for such a quick delivery. In CPC's delivery info page short lead time is described as item is not backordered but instead is available in supplier and can be shipped quickly. It took just 2 days for to me receive it. Hope this happens to be the case for the rest of the items I ordered :)
 
I don't know if im either going to order custom 2 x 7V r-core, OR if i should order a 2 x 9-12V r-core and rectify it feeding the dac with DC. I would actually like it better if it was possible to bypass the rectifier & first dc-regulator stage, feeding DC direct to it. With a shuntreg or so. Even though it seems like the PSU is designed well - we all know PSU can have a big impact on sound quality, so it would be good if it was possible to do that and try for ourselves.
 
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The footprint for the XLR jacks matches Neutrik NC3M**H jacks:

A- Series: "The `State of the Art` receptacle. Round plastic body XLR pcb mount panel connector. These have the smallest size and highest packing density (23mm between centres). New designed tulip type female contact on 3 pin versions and fork type on 4 and 5 pole female connectors with hard gold plating and polished contact areas."

NC3MAH

----

AA-Series: "New most cost-effective round plastic body XLR PCB mount panel connector. Front panel cutout and pcb layout 100% compatible to A series. New "tulip" type contact design with high contact pressure for highest durability."

NC3MAAH

----

B-Series: "Same as A series with exception of a metal mounting flange featuring continuous circumferential ground contact to chassis for best EMC practice. Available as 3 pole female and male connectors including a special version with 8 ground contacts (-E) for best conductivity of mating shell to ground."

NC3MBH
NC3MBH-B
NC3MBH-E

----

You can always wire from the board to panel mount XLR if you prefer.

Just so you don't run out and purchase XLR connectors:

The dam1021 R-2R DAC will be delivered with 2 pcs NC3MAAH connectors, 1 pcs 26 pin header, 1 pcs 10 pins header and 1 pcs 4 pins power header. They're not soldered on so you can decide which parts to mount yourself, or you can solder wires on.

Since this is diyaudio I assume everybody have a soldering iron and whatever else you might need....
 
Just so you don't run out and purchase XLR connectors:

The dam1021 R-2R DAC will be delivered with 2 pcs NC3MAAH connectors, 1 pcs 26 pin header, 1 pcs 10 pins header and 1 pcs 4 pins power header. They're not soldered on so you can decide which parts to mount yourself, or you can solder wires on.

Since this is diyaudio I assume everybody have a soldering iron and whatever else you might need....

Soren, thank you so much for your thoughtfulness! I hope the documentation writing is going well.
 
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