Buffalo II

[LeonvB]

Strictly spoken you don't need I/V stages. But the DAC will perform better if you do include them. A BOM is included in the integration guide, which can be found in the document repository (Twisted Pear Audio Document Repository). The choice for IVY or Legato is IMO a matter of taste.

 

[tunwadee]

Hi Leon, thanks for the super fast response! My apologies, but I'm not down with all the acronyms yet. By BOM do you mean Buffalo user manual?
Thanks

 

[tunwadee]

Sorry Leon
BOM = bill of materials!
Learning fast lol

 

[zkdaz]

Brian

Is the scheduled 'stampede'for buffalos on April 24th going to happen? Being Easters Sunday and so soon after your vacation.

Thanks

Dan

 

[zkdaz]

Well I guess not. Please can you update us on the release schedule for BII and other hard to get parts like placids and tridents, I have finally decided to take the plunge and build my first system;

XMOS USB when released
Buffalo II with Tridents
IVY III but I will buy the Trident III too and experiment
Sympaticos
Lowther DX4 drivers in 18" radius open baffles

now I just want to get on with buying and building it all.

Thanks

Dan

 

[headrott]

I promised some people a review of the Buffalo II with Tube-I-zator boards in output.

Here is the link on the Tube-I-zator board DYIAUDIO web page for pictures and a small review of the Buffalo II and Tube-I-zator SRPP output stage boards. Phenominal sound quality and I highly recommend building one!! Please ask questions if you have them. The link is here: http://www.diyaudio.com/forums/group-buys/156149-tube-i-zator-professional-pcb-52.html#post2561770 and it's post #519.

Greg

 

[sinski]

I just finished my Buffalo test setup:

The sound is very, very good. It is a great DAC.

I have some questions:

1. Legato should get from the PS 12V. Has anybody tried higher voltage - 13 or even 14 Volts ? If yes, than how does it affect the sound ?

2. I think that Tridents combo will be my next step and then ? Buffalo dual mono or better invest in two additional BP Placids for Legato ?

Anybody uses Legato with three BP Placids ? How does it influences the sound quality ?

 

[francolargo]

Re: the Legato, yes some users have tried higher voltages to good effect. The general consensus is that the voltage across the I/V resistor (R 1-4 on Legato 2?) should be set to about V+/2 -1. I use +15v and then adjust V- until there is ~6.5v across any of the 4 150R resistors. I suggest shunting 80-90 ma on the Placid BP.

Re: Tridents, the 1.2v VDD trident makes a huge difference in the performance of my system. Recommended! The Placid will run warm supplying Tridents so plan on a well ventilated chassis.

Enjoy!

 

[francolargo]

I use +15v and then adjust V- until there is ~6.5v across any of the 4 150R resistors.

Edit: I think the layout may have changed from the early version 2 schematic because I only remember two IV resistors on my Legato 2. they are the outermost of the three parallel 1W resistors, IIRC.

 

[ThuyTN]

Any idea about when more BII kits be available?

 

[pirastro]

Just completed the Placid power supply for B-II. Managed to figure out the current draw adjustment is simply to check there is no voltage drop for unloaded vs loaded (with B-II connected). Did a A-B comparison with an industrial type linear supply, was surprised to conclude that there isnt any distinct difference between the two! Hmm, guess money best spent elsewhere.

Need to watch out that the polarity of the two pairs of AC connection from transformer is connected as black-red-yellow-orange and not black-red-orange-yellow otherwise the transformer will hum and heat up. Not sure if this is particular to 230v AC connection, but its not stated in the Placid manual.

 

[pirastro]

Strictly spoken you don't need I/V stages. But the DAC will perform better if you do include them. A BOM is included in the integration guide, which can be found in the document repository (Twisted Pear Audio Document Repository). The choice for IVY or Legato is IMO a matter of taste.

I have connected B-II (with 3.3uF filter cap) out to TVC then to amp with decent sound but lowish gains (dependent on the input sensitivity of amps). Also, works fine with LDR with proper loading.

Any advise if I could employ a tube SRPP from raindrop_hui on ebay?

 

[MartinC700]

Just completed the Placid power supply for B-II. Managed to figure out the current draw adjustment is simply to check there is no voltage drop for unloaded vs loaded (with B-II connected). Did a A-B comparison with an industrial type linear supply, was surprised to conclude that there isnt any distinct difference between the two! Hmm, guess money best spent elsewhere.

Need to watch out that the polarity of the two pairs of AC connection from transformer is connected as black-red-yellow-orange and not black-red-orange-yellow otherwise the transformer will hum and heat up. Not sure if this is particular to 230v AC connection, but its not stated in the Placid manual.

No disrespect, but I think that you need to study the manual closely as well as perhaps looking up data sheets on components. To work optimally the Placid needs to have it's shunt current adjusted to ~60mA with the Buffalo running, just looking for a voltage drop will not do that, details are in the manual on the TP site.

You also really need to run the Buffalo into a I/V stage like the IVY or Legato, I am sure that other types will work but Russ and Brian have optimised their designes for the Buffalo.

Good luck and do be careful with your 230v connections !!

 

[pirastro]

Not sure if we are looking at the same manual, I have the Placid rev 2.0 output I measured the current per rail across R2/R5, initially I had 250ma, but the leds on the AVCC was very dim, in fact one side wasnt lit. I finally settled for 2.2R resistor in place of VR1/2 for approx 350ma.

Thanks MartinC700

 

[waltube]

To Russ:

I sent two email (on you site) asking the availabilty ic a 4:1 mux Spidf. Without answer.

Please can you tell me if there are some dates?

Thanks


Walter

 

[MartinC700]

Not sure if we are looking at the same manual, I have the Placid rev 2.0 output I measured the current per rail across R2/R5, initially I had 250ma, but the leds on the AVCC was very dim, in fact one side wasnt lit. I finally settled for 2.2R resistor in place of VR1/2 for approx 350ma.

Thanks MartinC700

Hi,

You should really measure the voltage across R3, and set this to approximately 0.06v, this will then be giving you 60mA of shunt current. I don't know if you have Tridents installed, if you do then you will need significantly more than 350mA. If you have no Tridents, then 350mA of total current should be fine, but you would still be better off measuring and adjusting the shunt current.

Regards

 

[Nikon1975]

Dear Russ,

Can I ask you what values you use for register 13 both in Stereo and in mono mode ?

Thanks,

Davide

 

[Nikon1975]

Dear Russ,

Let me reformulate my question in a more general fashion:

1) is it possible to have the diagram of connection of the output of the DAC chip to the output of the board ?

2) If I use an external controller, like the arduino, what are the function of the dip switch ? Can they be ignored ?

I started to play with the Arduino and the Buffalo. It's so much fun !!!


Thanks,

Davide

 

[glt]

The output connection is specified in the data sheet. The inputs to buffalo are a bit "tricky" to figure out, but Russ disclosed it somewhere in one of the threads. You can take a look at my Arduino code to see how they are set up...

If you use an external controller, you can ignore the dip switches...

 

[Nikon1975]

Hi glt,

I wrote also a comment on your website. Great work you did. You really opened me another world. I had to figure out how to regulate the phases of the outputs of all eight channels, and it was not so easy. Finally I read the original settings of the Buffalo in mono mode, and I could figure out how to have all the DAC working together.

I made a version of the code that supports both, stereo and dual mono.

Question: why do you need a transistor for the brightness of the display ? Can you show how you connected that ?

Thanks,

Davide