I know, the answer must be hidden in the threads, but search did not help.
So for any newbie building a Buffalo DAC with IVY who wants to look up the minimum ratings:
The transformers for the Placid Power supplies are rated
2x9V / 30VA
2x15V / 50VA.
But there is a lot of headroom.
What is the minimum VA one needs for driving a single and a bipolar Placid?
All the best,
Salar
So for any newbie building a Buffalo DAC with IVY who wants to look up the minimum ratings:
The transformers for the Placid Power supplies are rated
2x9V / 30VA
2x15V / 50VA.
But there is a lot of headroom.
What is the minimum VA one needs for driving a single and a bipolar Placid?
All the best,
Salar
Salar - i recently built Buffalo 3 with Legato 3.1 using standard 30VA Traffos (from on TPA site, though there's no longer 30VA option for 15V)
smooth dancer - Could you please describe the changes in sound when going from standard traffos to big ones? I built Buffalo 3 recently and due to shipping cost ordered only 30VA traffos, but now i think of jumping to something like 100VA for Legato (i guess 30va should still be enough for dac part?).
I already feel like sound could use more dynamics and attack compared to my older 4397 based dac with discrete output. Although there's a lot of stuff that makes me happy - the cleanness, precision, no "sharp edges" or digital grain. Maybe bigger traffo and increasing voltage to 15V should add that little bit of dynamics and attack i'm missing.
smooth dancer - Could you please describe the changes in sound when going from standard traffos to big ones? I built Buffalo 3 recently and due to shipping cost ordered only 30VA traffos, but now i think of jumping to something like 100VA for Legato (i guess 30va should still be enough for dac part?).
I already feel like sound could use more dynamics and attack compared to my older 4397 based dac with discrete output. Although there's a lot of stuff that makes me happy - the cleanness, precision, no "sharp edges" or digital grain. Maybe bigger traffo and increasing voltage to 15V should add that little bit of dynamics and attack i'm missing.
Hello to all,
thanks for the replies.
Maybe I´ll have to be a little more specific:
I will build an amp, with Buffalo and IVY and the needed Placids, all stuffed in one cabinet,
using a custom made toroid transformer with 6 secondaries.
The cabinet for all the components and pcb is very, very tight.
It took me two days just to shuffle around drawings of the pcbs to make everything fit and ensure heat dissipation.
So every mm is needed and there is literally no space to waste for any additional copper windings or VA that do not make sense.
In the moment a transformer with 300VA for the amp alone plus 30VA and 50VA secondaries would be too big.
(BTW, we are talking about 30/50 total, for both secondaries?)
There might be some headroom in my design, but as a start
a statement about the minimum VA for the current Placids would be very helpful.
thanks for the replies.
Maybe I´ll have to be a little more specific:
I will build an amp, with Buffalo and IVY and the needed Placids, all stuffed in one cabinet,
using a custom made toroid transformer with 6 secondaries.
The cabinet for all the components and pcb is very, very tight.
It took me two days just to shuffle around drawings of the pcbs to make everything fit and ensure heat dissipation.
So every mm is needed and there is literally no space to waste for any additional copper windings or VA that do not make sense.
In the moment a transformer with 300VA for the amp alone plus 30VA and 50VA secondaries would be too big.
(BTW, we are talking about 30/50 total, for both secondaries?)
There might be some headroom in my design, but as a start
a statement about the minimum VA for the current Placids would be very helpful.
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Why so small cabinet ? It just complicate things. I guess you want to get the best sound out of your dac ?
I ended up with two cabinets. One for the trafo's and Placid BP's, and the other one for two BIIIse in dual mono.( with Placid HD's and Ivy's.)
Big enough trafo's is a must to get max out of the Buffalo dac.
( Sry for not give an answer to your question )
I ended up with two cabinets. One for the trafo's and Placid BP's, and the other one for two BIIIse in dual mono.( with Placid HD's and Ivy's.)
Big enough trafo's is a must to get max out of the Buffalo dac.
( Sry for not give an answer to your question )
The answer is easy then - the smallest traffo Twisted Pear offered previously was 30VA, now they only offer 50VA for BP, so I guess 50VA is optimum but since 30VA worked - it's minimum. At least I use it with 30VA for now and it work, although like I said earlier - I feel like It could use a bit more dynamics\attack and I expect to get that with new 100VA trafo and new Placids.
I'll report back when I triy 100VA traffo - if difference will be huge the 30VA probably won't be a good choice then...
I'll report back when I triy 100VA traffo - if difference will be huge the 30VA probably won't be a good choice then...
That's not at all what that thread is saying.
The Placid is not drawing that much; the boards he is powering is drawing that much. The Placid, by itself, will draw slightly more current than you set it to shunt.
You need to determine the load you are presenting to the Placid (what modules you are powering), plus the shunt overhead.
The size of your transformer is dictated by this, not the Placid itself.
My BIIIse with Tridents draws around 550mA (with Exa) Shunting appr.60mA
Ivy around 150mA ( 75mA from each half on Placid BP ). Shunting appr. 60mA
In my BIIIse's the I2C header feeds Exa usb-I2s device with 3v. If not using the I2C on BIIIse, I guess 490-500mA current is correct.
Ivy around 150mA ( 75mA from each half on Placid BP ). Shunting appr. 60mA
In my BIIIse's the I2C header feeds Exa usb-I2s device with 3v. If not using the I2C on BIIIse, I guess 490-500mA current is correct.
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Hello Smooth Dancer,
60mA shunting is for the new HD Placids?
Then absolute minimum transformer should probably be:
BIIIse = 610mA x 9V = 5.5 VA
IVY = 210mA x 15V = 3.1 VA
I guess even 10VA for the Buffalo IIIse and even 5VA for the Ivy should be
sufficient without stressing / heating the transformer?
Anyway, for my design I will choose the "old" transformer ratings of 15VA for the Buffalo and 30VA for the IVY.
This is almost three times available current for the BIIIse and almost ten times current for the IVY.
All the best,
Salar
60mA shunting is for the new HD Placids?
Then absolute minimum transformer should probably be:
BIIIse = 610mA x 9V = 5.5 VA
IVY = 210mA x 15V = 3.1 VA
I guess even 10VA for the Buffalo IIIse and even 5VA for the Ivy should be
sufficient without stressing / heating the transformer?
Anyway, for my design I will choose the "old" transformer ratings of 15VA for the Buffalo and 30VA for the IVY.
This is almost three times available current for the BIIIse and almost ten times current for the IVY.
All the best,
Salar
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I finally installed my new custom made 100VA trafo (placid 2.1, 13V) and the difference is...huge.
To be honest - i didn't expect this, but a friend of mine who professionaly work in this field told me that because my stock 30W trafo was getting warm\hot - it is a bad sign and it may be working out of it's optimal\linear range and only then i finally i decided to try replacing it...
To make description short - the improvements are largely in dynamics and bass with some additional cleanness as bonus. The buffalo was always nice and clean, but slightly anemic compared to my other dac. Now the dynamics is overhelming and it got what was missing - the "bite" and attack as well as firm bass.
So i guess one should not use Legato 3.1 with anything less than 50W
To be honest - i didn't expect this, but a friend of mine who professionaly work in this field told me that because my stock 30W trafo was getting warm\hot - it is a bad sign and it may be working out of it's optimal\linear range and only then i finally i decided to try replacing it...
To make description short - the improvements are largely in dynamics and bass with some additional cleanness as bonus. The buffalo was always nice and clean, but slightly anemic compared to my other dac. Now the dynamics is overhelming and it got what was missing - the "bite" and attack as well as firm bass.
So i guess one should not use Legato 3.1 with anything less than 50W
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How would this happen? I could understand maybe clipping with not enough power, but better sound with excess power? Can someone explain the science?
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