Søren posted recently that a manual will be ready when the boards ship - he was finishing the firmware for release and would start writing the documentation once that was done.
There was some discussion in this thread about multi-board setups. You'd have to dig back and find the posts.
** Just checked the first post and see that Soekris has just updated it with information that first batch is sold out, and second batch is close to being sold out.
I wonder how many DIY oriented products sell 600 boards in less than 3 hours?
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I suspect most members have their preferences set so that they see the most recent posts when they click on a thread.
Paid for one 0.2%. Thanks Soekris.
Please for the traffo: how much VA advised if a 2x9V ?
2x9V trafo is not recommended as it don't leave margin for line voltage and load variations....
But not much power is needed, playing music at full power here I have a load of 2.2W at +-10V DC.
There is a Farnell part that was suggested by a member:
MCFM50/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 5VA | element14 Australia
Element14/Farnell are out of stock.
However, there is a UK based eBay seller who does have stock:
MCFM50/07 Multicomp Mini-Toroidal , 5Va 2X 7V | eBay
I got one from this seller and the transformer arrived in Farnell packaging.
MCFM50/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 5VA | element14 Australia
Element14/Farnell are out of stock.
However, there is a UK based eBay seller who does have stock:
MCFM50/07 Multicomp Mini-Toroidal , 5Va 2X 7V | eBay
I got one from this seller and the transformer arrived in Farnell packaging.
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Søren has repeatedly said 6-7V and 5W, and said a couple of posts prior to mine that 9VAC is too high.
10V refers to DC voltage - and obviously if you rectify 7VAC to DC you get:
7 x 1.414 = 9.898V DC or close enough to 10VDC
The reason Søren is warning against using 9VAC is that the rectified DC voltage is:
9 x 1.414 = 12.726VDC which is fine while the Trafo is loaded.
But the off load voltage output by the transformer can rise by around 18-23%. The one I linked to has a regulation spec of 18%.
So unloaded:
7VAC x 18% = 8.26 x 1.414 = 11.68VDC
9VAC x 18% = 10.62 x 1.414 = 15.016VDC
Even at 18% off-load regulation the 9VAC secondaries are at the maximum limit of the board.
The 10VAC Trafo you think Søren was proposing:
10VAC x 18% = 11.8VAC x 1.414 = 16.68VDC = toasted Soekris R2R DAC.
cheers
Paul
I will use 15-0-15-0 troidal transformer and this regulator.
4.17uV Ultralow noise DAC power supply regulator +-12/15V 1A - DIYINHK
at the end u get 12v 1A regulated power.
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There might be a qty 5 limit for first batch to control things, but send the website where you ordered a note and I'm sure they will combine....
You also need to account for line variation, I typical put that at +- 15%.
So at max 16V DC internal gives: 16 + 0.5 (diode bridge) / 1.15 (high line) / 1.25 (load reg) / sqrt2 = 8.1V
And at min 7V DC internal gives 7 + 0.5 (diode bridge) * 1.15 (low line) / sqrt2 +1 (ripple) = 6.8V
So trafo have to be specified at 2x 7V-8V AC when you account for line and load regulation. But nothing stops you by powering it by a DC power supply....