Legato or IVY III outputs for Buffalo II?

[pelliott]

I had to increase to voltage across R1 and R2 to .3vdc in order to get a healthy 12volts when I loaded with the Lagato.
Just curious, will current demands go down or up if I increase voltage toward 15v. I have plenty of ventilation and the PS is in a different box than the Buff/Lagato.
After almost 100 hours it is really sounding very good. I am using the OPA2227 in the buffer.

[Russ White]

Yes, the current demanded will go up with the voltage.

I am glad you are enjoying it!

Cheers!
Russ

[needsp]

Hi Pelliot

When I went from 12 to 15V, the total current (for just the I/V stages- no buffers, no Bal/SE stage) increased from 180mA to 200mA

Paul

[chipzahoy]

Just one more question concerning Legato's construction options. If I wish to filter GND, do I place C1-C4 over the purple and green pads?

Thanks!

[needsp]

Hi chipzahoy

Al you need to do is look at the tracks on the underside of the board, and trace them back to the supply inputs. Then you'll be certain!

Paul

[chipzahoy]

Haha, I would, except my Legato probably won't arrive until September (still waiting for my BufII pre-order). I guess I'm just being a little too enthusiastic

[igwt]

Hello Russ,
Is the current listed in the Legato manual 360ma total or 360ma per rail?+/-

Thanks-
igwt

[AussieAmpBloke]

igwt,

Both!
360mA per rail is 360mA through the whole thing.

[prooptiki]

Originally Posted by AussieAmpBloke

igwt,

Both!
360mA per rail is 360mA through the whole thing.

Originally Posted by needsp

Hi Pelliot

When I went from 12 to 15V, the total current (for just the I/V stages- no buffers, no Bal/SE stage) increased from 180mA to 200mA

Paul

The current without buffers, and Bal/SE stage is ok around 200mA?
Current without Bal/SE stage ?

From the manual!
"Adjust VR1 and VR2 on the Legato until each of the inputs sit as close to AVCC/2 as possible.
Don't sweat over this very much. Testing has shown that anything close is just fine."

This last adjustment should be made with or without the buffalo dac?
Thanks

[AussieAmpBloke]

Originally Posted by prooptiki

The current without buffers, and Bal/SE stage is ok around 200mA?

What do you mean by "is ok"?
Is it normal for it to draw that much current? Yes.

Current without Bal/SE stage ?

You mean with buffer, but no BAL/SE? Then you'd be looking at about 280mA at +/-12V or about 340mA at +/-15V.