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Buffalo II & transformers

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With the quality and price of the Feastrex transformers, a top notch quality resistor is in my oppinion mandatory. You might want to try these resistors:

* TX2575 bulk metal foil type
* Caddock Mk132
* Caddock USF TF020/USF340
* Tantalum by Shinkoh
* PRP PR9372


/S.

Hi, staccatiss,

I had simply inserted load resistor in secondary as their recommendation.
I used 2.4k ohm generic metal film I just found in my junkbox.

I felt "brightness" in treble decreased with Finemet transformer in comparison to previously used I/V stage. That's not always, but with some recordings.


Later I realized this kind of brighter treble of previously used discrete op amp I/V tend to have fogginess - this actually masked details in some extent - at the same time.

Here's related article in Mr. Yukihito's blog. (in Japanese only)

Feastrex????????????????? | SD????????????????

Cheers,
 
I must correct impressions in my previous post

I have recently noticed that my BII hadn't work properly at least during borrowing the Finemet transformers.
Somehow one of the 8 outputs in the dac failing to output (+) correctly.

After receiving the transformers that I had ordered, I had re-checked the dac and made sure working properly.
Now BII with Finemet transformer sing much better.

I have to correct my previous impression of them, especially about treble and soundstaging.
High frequencies now have enough sparkle and more airly presentation.


Cheers!
 
NOW TRY THIS:

An externally hosted image should be here but it was not working when we last tested it.
C:

What you might call this, I don't know. It is not current I/V in the regular sense. But do note that we now have traded some of the offset voltage for current offset. Again the maths is simple, same as above:

1.65V/(195+330R) = 3.1mA

The offset voltage will be just above 1V DC. That DC will not go through the transformer, only AC current will be seen by the Primary. Looking AC wise, it also looks like a voltage divider:

(330R(195R+330R))*2.1VRMS = 1.3VRMS

But there is also another way of looking at it: The 3.1mA DC current offset is at least less that a tenth of the peak AC current required on the Secondary of the 1:1 transformer in pretty much all circumstances. The Sabre DAC is essentially modulating that current. Think of it as an iddle current being modulated.

Some kind of current processing is going on, but not in the sense of a proper I/V converter - which I still believe to be ideal, but maybe we are not looking for the ideal, just a better compromise for transformer use.

Bottom line, IF only 1.3V RMS output does not ruffle your feathers (it does some, but shouldn't), then like any good soup, how does it taste?

Cheers, Joe R.


Hello Joe !

I've tested this one ....Excellent !!!
I had on my shelves, an very good Jensen JT11-EMCF, a 600:600, 80% nickel core, 40 Ohms DCR Pri/sec
I've spent my afternoon to play music (about 60 p.) , listening with a special care my "reference playlist"
This simple combination gives a very good resolution with details, opened-air music ...

Thanks to Joe, for this excellent suggestion !!!

Richard
 
Hello Joe !

I've tested this one ....Excellent !!!
I had on my shelves, an very good Jensen JT11-EMCF, a 600:600, 80% nickel core, 40 Ohms DCR Pri/sec
I've spent my afternoon to play music (about 60 p.) , listening with a special care my "reference playlist"
This simple combination gives a very good resolution with details, opened-air music ...

Thanks to Joe, for this excellent suggestion !!!

Richard

Hello Richard
I think, I read that you were using the jt-11p-1, these jt11-EMCF sound better with the buffalo II ?
thanks for the reply, greetings Loredana
 
Hello Richard
I think, I read that you were using the jt-11p-1, these jt11-EMCF sound better with the buffalo II ?
thanks for the reply, greetings Loredana

Yes, I was using JT-11-P1, that was during several months...after a quick start with TPA first output stage bought with Buff-9008


Then ,until now, I tried an Edcor, wired ~7x, with 1800 Ohms on secondary, followed by a tube buffer...

If I compare JT11p1 with JT11-emcf, the sound was more "concentred" to mids and hights, with a bit of "metallic" in upper frequencies

The main difference now, is in "natural sound" , and an "opened air", with strong low freq.

I think to test in some weeks, "current mode" with 3 ohms and tube output stage ~40-50x gain

Richard
 
I have a pair of BIIs running in dual mono mode. The outputs are fed directly into a pair of Joe's quadfillar wound transformers (195ohm impedance). When Joe first shared his resistor loading trick with me, I tried 150ohms, then 75ohms and now 47.5ohms. The results were truly pleasing. I am now tempted to go even lower as I have more than enough gain in my line-amp.
 
Hello Joe !

I've tested this one ....Excellent !!!
I had on my shelves, an very good Jensen JT11-EMCF, a 600:600, 80% nickel core, 40 Ohms DCR Pri/sec
I've spent my afternoon to play music (about 60 p.) , listening with a special care my "reference playlist"
This simple combination gives a very good resolution with details, opened-air music ...

Thanks to Joe, for this excellent suggestion !!!

Richard

I still think somebody should try this with a Sabre DAC using Tubes.

IV-Tube.gif


Normally Tubes are only good for voltage DACs, but use a transformer like this and you will have a Tube I/V stage - and it is the Sabre DAC that makes it possible - offset current = 8mA (I wouldn't do this with any other DAC I could think of). It can be pulled all the way to ground on the Primary and the Secondary grounded - and just input to the grid of your favourite Tube - and away you go.

Somebody should try it - requires gain about 50.

Cheers, Joe R.
 
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I have finally connected the synchronous Buffalo2 to the SDTrans384 running version 17 and 3.11. I am now also using the Feastrex urushi-treated transformers with the Caddock TF020 4k02 Tetrinox resistor, the Reliable Capacitor 10n Teflon and Tin foil capacitor as transformer load, cryod purest solid core copper wire, and solid core cotton insulated silver wire together with Furutech rhodium RCA connectors. The Buffalo2 has no Tridents. SDtrans and Buffalo2 are powered by separate transformers+rectifiers+regulators.

Music has never sounded as good as this before! Most notably, the music swings, that is, the music makes my feet tap automatically, and sounds organic. Stereo depth/front/sideways has increased. And, there is a blackness of the background and in between instruments that is awesome. Sibilants (for ex s-sounds) sound non irritating (when the recording is not too bad). Voices are fantastic. It is easier to hear individual voices in a choir, and the echo of Mark Knopfler´s voice in "Private Investigation" is easier to pick out.

During playback of one of my reference songs, the saxophone sounded as it stood just to the left of me - I almost fell of my chair. Almost scary.

The only weakness I find is that the bass could have a bit more weight but maybe I need to get bigger speakers instead.

Bunpei - thank you very much for bringing me the SDTrans and Feastrex transformers!



/Staccatiss
 
Some images attached.

I have finally connected the synchronous Buffalo2 to the SDTrans384 running version 17 and 3.11. I am now also using the Feastrex urushi-treated transformers with the Caddock TF020 4k02 Tetrinox resistor, the Reliable Capacitor 10n Teflon and Tin foil capacitor as transformer load, cryod purest solid core copper wire, and solid core cotton insulated silver wire together with Furutech rhodium RCA connectors. The Buffalo2 has no Tridents. SDtrans and Buffalo2 are powered by separate transformers+rectifiers+regulators.

Music has never sounded as good as this before! Most notably, the music swings, that is, the music makes my feet tap automatically, and sounds organic. Stereo depth/front/sideways has increased. And, there is a blackness of the background and in between instruments that is awesome. Sibilants (for ex s-sounds) sound non irritating (when the recording is not too bad). Voices are fantastic. It is easier to hear individual voices in a choir, and the echo of Mark Knopfler´s voice in "Private Investigation" is easier to pick out.

During playback of one of my reference songs, the saxophone sounded as it stood just to the left of me - I almost fell of my chair. Almost scary.

The only weakness I find is that the bass could have a bit more weight but maybe I need to get bigger speakers instead.

Bunpei - thank you very much for bringing me the SDTrans and Feastrex transformers!



/Staccatiss
 

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The only weakness I find is that the bass could have a bit more weight

Try a pair of resistors, depending on the configuration of the Buffalo and how many DACs are in parallel, 330R (4 Stereo) of 100-180R (8 Mono) from either phase to ground - the tonal balance and weight should improve in any system. It's only a pair of resistors, nothing to loose.

Cheers, Joe R.
 
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Staccatiss if you will have a quite large capacity on the AVCC pins of the ESS9018, then you will have that bass you want/wish. And even more...
As I understood, you do not use Trident. If you use serial regulators for Buffalo, then you can just proceed with this suggestion.
You can just solder some extra ceramic caps (100µ/6V) over the existing ones on the Buffalo board. Or in the way you can see in my picture of the first post in my thread. You can solder together in a pack few or more such ceramic caps and then attach the packs over the existing caps for AVCC pins. It could be enough with two packs on each side of the chip.
I do not have your audio system configuration, but with mine (quite simple one, and hand made), I can well recognize your described sound (scene). I just wonder how it could sounds your system with the proposed above solution...
 
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