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Buffalo II

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Well, I finished my Buffalo 32S just a couple months ago. I find it is very good. One minor drawback is that I find it misses a little dynamics and sounds a little soft or laid back.
What are the major differences in sound between this DAC and the previous one? I suppose that it depends a lot on the output stage used, but perhaps you can give some subjective opinion for me to chew on?
Thanks Russ, and keep up the awesome work!
Byron
 
Okay, i've got my BII !
It's going to be fun to see people showing their own made adaptable IVY
(with groupbuy for boards:))

Any news on this Russ ?

"Also Counterpoint II is in the works.
And the very remote possibility of a tube output stage for a little fun".
 
I find it is very good. One minor drawback is that I find it misses a little dynamics and sounds a little soft or laid back.
What are the major differences in sound between this DAC and the previous one? I suppose that it depends a lot on the output stage used, but perhaps you can give some subjective opinion for me to chew on?
Thanks Russ, and keep up the awesome work!
Byron

Definitely not the way I have heard it described. :) Perhaps different from what you are used to?

I try not to make subjective descriptions of my own stuff. How is this - It keeps me in my office listening to music hours beyond what I am supposed to. :)

Cheers!
Russ
 
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Dear Russ,

could you be so kind and elaborate a bit about mono mode for the Buffalo II?
How does it work?
How do I choose channel?

Regards,

It is pretty simple. There is a "stereo/mono" switch and a "Left/Right" switch.

In mono mode the left/right switch determines which channel is converted. The active channel side of the DAC will be in phase. The opposite side will be out of phase. When connected to an IVY-III this will result in an in-phase(+) signal for that mono channel on the active channels SE output, and the anti-phase(-) signal being on the other SE output. Use them both and you have a mono balanced output. :)

I hope that helps clear it up a bit.

Cheers!
Russ
 
Dear Russ,

thanks for explaining the mono "mode". If I get it right, in mono mode the left_HOT and left_COLD (in phase and out of phase signals respectively) will
each have 4 converters running in paralell on one Buffalo II_Left_Ch PCB and then the right channel will use the 8 converters on the other Buffalo II_Right_Ch PCB?
That is pretty amazing!
What will the current out swing be then per phase?


What does the other switches do?



Regards,

It is pretty simple. There is a "stereo/mono" switch and a "Left/Right" switch.

In mono mode the left/right switch determines which channel is converted. The active channel side of the DAC will be in phase. The opposite side will be out of phase. When connected to an IVY-III this will result in an in-phase(+) signal for that mono channel on the active channels SE output, and the anti-phase(-) signal being on the other SE output. Use them both and you have a mono balanced output. :)

I hope that helps clear it up a bit.

Cheers!
Russ
 

opc

Member
Joined 2004
Paid Member
D1B1 I/V Stage for Buffalo II

Hi Russ,

My order for a Buffalo II was placed yesterday, and I'm looking forward to getting it! In the meantime, I'm working on a layout for my D1B1 I/V stage, and I was hoping you could provide me with the following:

-Spacing and exact location of the DAC output terminals
-Tallest component height on that side of the PCB.
-Overall PCB dimensions including hole locations.
-Distance from the output connectors to the digital input connector.

I'm designing an I/V stage that will drop directly on top of this, and it would be nice to have it ready for when the DAC arrives. Details are here:

http://www.diyaudio.com/forums/digital-line-level/154866-new-take-classic-pass-labs-d1-ess-dac.html

I'm guessing I'll have to add a little more height than I was initially expecting to clear the regulator daughterboard. Could you also let me know how tall that is once installed?

I'm looking forward to trying the new DAC!

Cheers,
Owen
 
Hi Russ,

I'm working on a layout for my D1B1 I/V stage

Cheers,
Owen

Hi Owen,

Nice project! Ah yes, the D1. :) I am quite familiar with it.

I have already tried such a stage (almost exactly the same), and have this word of caution, while it will sound very good, it will have a very bad turn off transient, and it happens to fast for a mechanical relay to catch. This is why I have not pursued the D1 as an output stage. I really don't want people to blow speakers. :)

The counterpoint-II was specifically designed to have the same sort of common-base conversion, but without the transient behavior and with much lower input impedance. It is tested and the Counterpoint II has no turn off transient. So if you like the D1 I very much think you will like the CP-II.

I don't say this to discourage you, but on the contrary I actually encourage you to try it. Just please do a prototype first and watch carefully the turn off behavior. Keep in mind, many folks will go direct out of the I/V stage into a power amplifier. So test it as such.

I will send spacing and whole details for you in a while.

Cheers!
Russ
 

opc

Member
Joined 2004
Paid Member
Hi Russ,

You should read over that thread, I cover a lot of that stuff. I've been living with the prototype for several months now, and although there is a small pop on startup, there is no strange transient on shutdown. I'm using a B1 jfet buffer in place of the original mosfet buffer Nelson uses, so that might account for the different behavior. I haven't bothered trying to minimize the pop on startup, but I'll certainly look into it. The proper schematic is a few pages into the thread.

I'm also running far more bias, lower rail voltage, and much lower impedance at the source than the original D1. In fact, I'm seeing only 50 mV of swing at the DAC output for 7.5mA out of the DAC, which is an impedance of 6.5 ohms. What impedance does the Counterpoint present to the DAC?

I'll put some effort into minimizing turn on pops, and I'll let you know how it goes. No doubt if it's going to be provided to others for use, it will have to be well behaved under all normal circumstances.

I'm looking forward to those dimensions!

Thanks,
Owen
 
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