Buffalo II & transformers

[RichLund]

Hi guys

Is there any proven circuit for connecting 600:600 transformers (I'm using UTC A-20's) to the Buf II? Just straight from the output to the primaries? And what about the secondaries - RC filter, or just a resistor?

Thanks,
Fedor

Hi Fedor

Just as an experiment I am trying UTC A-20's on the IVY 3 as balanced to SE converters connected to the balanced outputs. I realize this goes against the TP design philosophy but it's just for fun. It works well anyhow apart from a slight buzz. I'm wondering should I connect the balanced output GND to the UTC A-20 GND pin?

Below is the filter setup I am using for secondaries. The primary resistor values can be played around with to suit. The transformers are configured as 1:1 -

 

[BrianDonegan]

I realize this goes against the TP design philosophy

How so?

 

[fred_com]

Hi Fedor

Just as an experiment I am trying UTC A-20's on the IVY 3 as balanced to SE converters connected to the balanced outputs. I realize this goes against the TP design philosophy but it's just for fun. It works well anyhow apart from a slight buzz. I'm wondering should I connect the balanced output GND to the UTC A-20 GND pin?

Below is the filter setup I am using for secondaries. The primary resistor values can be played around with to suit. The transformers are configured as 1:1 -

Hi Rich,

Sorry, I can't answer your question, I don't have an I\V stage, and right now I've just connected +/- terminals of the DAC straight to the transfomer primaries. I'm using the same filter on the secondaries (left from when UTC's were connected to the Gigaworks Dac).

Thanks,
Fedor

 

[RichLund]

Hi Fedor

Sounds like we are beating the same track. I also have the Giga DAC which I used the A-20's on. It made a massive difference to that DAC but only slight difference when used with the Buffalo IVY.

I have been switching between the standard IVY SE outputs and the the transformer outputs and I have to say I quite like the transformers. A warmer, analogue presentation. Slight loss of ultimate clarity maybe but very comfy. I may sell the A-20's and try Jensen JT-11-EMCF or some Onetics. I have also connected the signal GND to the GND tab of the A-20's and it reduced the hum significantly.

Are you using resistors on the primaries when direct to the Buffalo?

 

[chipzahoy]

Connecting the signal GND to the chassis fixed the hum for me. Maybe I should try the transformer GND instead, sounds like a better idea.

 

[fred_com]

Hi Rich

Thanks for the tip about connecting A-20's GND to the Buff II output GND - just tried this using a wire, and hum level is indeed reduced a lot.

I'm not using any resistors on the primaries at the moment. Actually, I'm unsure what resistors values to use and how to connect them, if they are needed.
There's one circuit I wanted to try, and maybe will do it later. Other than that, I'm stumped.

<offtopic> BTW, thanks for the idea of VREF mod on Giga DAC - it made a final point in the series of the mods on this great DAC. </offtopic>

Fedor

 

[piecor]

Hello Folks!

I used the Lundahl LL1690 with the Gigawork (CS4398 and CS4397 versions) with huge results. In that case I connected the trafo as suggested by Per Lundahl, tha is: dac connected to the trafo with no additional components, a single 7K resistor across pin 9-10, pin 3 grounded... that's it!!!!

Le me ask some questions:

1. If I understood right the Buffalo doesn't need a SPDIF receiver, is that correct?

2. did somebody tried the LL1690 with the Buffalo II?

3. any comparison with the Gigaworks dac?

Best Wishes
Pietro

 

[RichLund]

Hi Pietro

1. Correct you can connect the input straight to the DAC. However I understand that the Wolfson chip on the receiver module considerably reduces jitter so may well sound better. This is something I'm about to try myself.

2. They should work no problem if I got my A-20's to work with it. The Lundahls should sound good.

3. I also have the Giga DAC and as good as it is, it's nowhere in the same league as the Buffalo. The Buffalo really is a superb sounding DAC. If your'e thinking of getting one... do it.

Hope that helps

 

[piecor]

Hi Pietro

I also have the Giga DAC and as good as it is, it's nowhere in the same league as the Buffalo. The Buffalo really is a superb sounding DAC. If your'e thinking of getting one... do it.
Hope that helps

is the difference between the two dacs that drammatic? And if yes, what are the relevant parameters based on which you judge the BUffalo to be superior?

Best
Pietro

 

[Spartacus]

1. Correct you can connect the input straight to the DAC. However I understand that the Wolfson chip on the receiver module considerably reduces jitter so may well sound better. This is something I'm about to try myself.

I've done this, definitely worthwhile if you have a source with significant jitter.

 

[RichLund]

is the difference between the two dacs that drammatic? And if yes, what are the relevant parameters based on which you judge the BUffalo to be superior?

Best
Pietro

Well, the parameters are 'does it make my music sound better' kind of parameters. I could waffle about soundstage, imaging and some such subjective descriptions but at the end of the day - the Buffalo makes music sound better.

Which it should anyway. The fact that it sounds better than the Gigaworks DAC isn't surprising considering the Buffalo is very carefully and thoughtfully designed with high quality SMD components and features that have been decided on by hours of extensive listening form Russ and Brian. The output stage is the IVY 3, which is again carefully selected and designed all powered by the excellent Placid power supplies.

The Gigawork DAC on the other hand has been hastily assembled using whatever old stock components are available at the time and has a very questionable power supply and regulator section. The fact that it does sound so good in the first place is testament to the Cirrus Logic chipset and their application note circuits. The Giga DAC only really shines when a lot of modification is done to the output and power / regulation sections.

 

[Bassivus]

is the difference between the two dacs that drammatic? And if yes, what are the relevant parameters based on which you judge the BUffalo to be superior?

Best
Pietro

Indeed VERY DRAMATIC OK I have never herd the big board giga dac just small one but Buffalo is another universe

 

[Jeffrey Davison]

Have you received an answer to this? Anyone else care to answer?


JD

Hello everybody,

Did enybody try output transformers with two buffalo II as dual mono ?

In dual mono mode i see (from the connection diagram with the IVY) that all 4 output signals (OUT_R+, OUT_R-, OUT_L+, OUT_L-) are used per channel, instead of 2 output signals per channel in stereo mode .
What would be the transformer connection diagram then?

 

[sinski]

Hi,

Has anybody connected Jensen JT-11-EMCF to BII ?

At the moment i have a gigaworks dac with Jensens, now thinking about Buffalo with Jensens...

 

[David Garretson]

Jeffrey, As I understand dual mono, two Buf modules can simply be paralleled into one pair of transformers.

I'm two days into a Buf II with Tridents and Placid PS into 1:2 Audio Consulting New Silver Rock transformers buffered with LME49600, all on SLA battery power. This is a righteous sounding combination.

Can anyone describe what they hear with dual mono vs. one Buffalo? Tough to leave well enough alone.

 

[sjalloq]

David,

are you using the LME49600 to drive headphones? How have you set it up?

Thanks.

 

[David Garretson]

The step-up transformers are followed with 4x LME49600 to XLR output of CDP. The buffers can be used in this manner as a reflective load or alternatively on the primary side. Either way this is a good way to operate the Sabre chip in voltage mode and combine the advantage of galvanic separation with current drive. This sounds in every way superior to transformers sans buffers.

Sonic performance of the monolithic buffers depends on quality of PS and bypassing. I use low impedance +/-12V SLA batteries with lots of capacitance, and triple bypass each power pin with 1500uf ZL Rubycon electrolytic, .1uf Russian polystyrene, and .01uf Russian teflon. I have not tried them with the Placid regs.

 

[joemana]

If you guys want the transformer output, you should try this one.
audio-talk :: View topic - Buffalo DAC output stage

I started my Bufallo II with IVY III, then replaced IVY with Lampizator output stage, the guy selling the Lampizator board had a glowing review with the Salas Shunt regulator injected to B+ of the Lampizator, so I did try, maybe my ears is not sensitive enough to hear the good stuff and still not satisfied, then I modified the Lampizator and hooked the circuit above link. I like the sounds of Buf better with the output stage link above. The instruments are clearer so with the vocals.

Joe

 

[gioz]

Jeffrey, As I understand dual mono, two Buf modules can simply be paralleled into one pair of transformers.

I'm two days into a Buf II with Tridents and Placid PS into 1:2 Audio Consulting New Silver Rock transformers buffered with LME49600, all on SLA battery power. This is a righteous sounding combination.

Can anyone describe what they hear with dual mono vs. one Buffalo? Tough to leave well enough alone.

Hi David,
what kind of battery do you use with buffalo?
Do you have connected the battery directly to placid without modification?

 

[David Garretson]

Gioz, I use a 95AH Enersys Odyssey PC2150 to supply Placid and the entire CDP including transport except for the SS buffers, which can run on smaller +/- batteries. The Odyssey was chosen for its AH reserves, deep-cycle capability, and low 2 milliohm internal resistance. In this application it drains .2V in a long evening. I attached the battery to some gold pins inserted in through-holes at the output side of the vacated rectifier position on Placid.